This thesis focuses on the study of hydrogen dynamic behavior in a series of proton sponge cations as well as in bis(silyl)hydride organometallic complexes. To understand the dynamic behavior, a new tool, i.e. the three-dimensional vibrational Schrödinger equation has been derived and solved. Three different vibrational patterns for hydrogen motion have been revealed. The classification of proton sponges and bis(silyl)hydride complexes into those with localized and delocalized hydrogen behavior has been proposed. For the organometallic complexes the influence of the vibrational motion of the hydrogen on J(Si−H) spin−spin coupling constants has been studied. Also this thesis presents a study of [Cp*Co(SiR3)2(H)2] cobalt complexes and their iridium analogues to detect possible Si···H interactions. Based on molecular geometries, Wiberg bond indices, and J(Si-H) spin-spin coupling constants, at least two residual Si···H interactions have been detected in cobalt complexes while there are ...
Immobilization of two organometallic complexes into a single cage to construct protein-based microcompartmentImmobilization of two organometallic complexes into a single cage to construct protein-based microcompartment ...
June 20, 1967 M. cAls ETAL. 3,326,948 ORGANOMETALLIC COMPOUNDS AND THEIR PREPARATION Filed May l?, 1962 United States Patent C) 5,5 12 Claims. (Cl. 260-429) This invention relates to organometallic compounds of the kind in which at least one transition-metal carbonyl group is bound by a 1r-bond to a hydrocarbon or substituted-hydrocarbon molecule having available 1r electrons. Known compounds of this kind include, for example, cyclopentadienyl compounds such as cyclopentadienyl manganese tricarbonyl. Moreover, dicyclopentadienyl iron compounds are known (usually referred to as ferfocenes) in which an iron, cobalt, nickel or ruthenium atom is bound by fr-bonds to two cyclopentadiene radicals. Such organometallic compounds are suitable for many different technical applications. They may serve, for example, as additives to fuel or to lubricants, as drying agents to be incorporated in drying paints, varnishes, oils or resins, as intermediates in the manufact-ure of metalcontaining polymers, and for ...
Formation of organometallic complexes of platinum(II) and platinum(IV) in reactions of PtCl62− with alkanes, olefins and aromatics induced by γ-irradiation | Mikhail V. Serdobov; Galina V. Nizova; Georgiy B. Shulpin | download | BookSC. Download books for free. Find books
0075]FIG. 3 illustrates a bottom-spraying fluidized-bed granulation system. The spraying nozzle 22 is placed at the bottom of the tank, at the center of the perforated plate or grille 13, and a cylinder 32 is mounted thereon. Spraying of the aqueous solution of organometallic complex is performed from the bottom upward. The apparatus is composed of a conical-shaped removable tank 33 of Wurster type that fits onto the housing of the sleeve filter 15 of the apparatus. The tank 33 comprises a perforated tank bottom plate 13, a cylinder 32 (optional) located in the lower part of the tank above the perforated plate, and the height of which is adjustable, and a nozzle 22 located at the center of the perforated plate 13, under the cylinder 32, and oriented for spraying from the bottom upward. The larger volume of air that pass through the center of the perforated plate 13 and the inner cylinder 32 thereby create an ascending flow 31 of material, which then redescends outward, giving the particles in ...
tats This invention relates to novel organometallic compounds and their preparation. More particularly, the present invention relates to novel and useful transition metal complexes of azulene. An object of this invention is to provide a novel class of organometallic compounds. Another object is to provide a class of stable transition metal coordination compounds of azulene. A further object is to provide a novel class of stable non-ionic azulene metal complexes having unsymmetric configurations. Other objects will become apparent from the specification and claims which follow. The above objects are accomplished by providing nonionic complex compounds of the metals of groups IVB- VIII in which a metal atom or atoms are bonded to azulene, which compound is stabilized by additional covalent bonding of the metal atom or atoms to dissimilar electron-donating groups. The metal in the novel compounds of this invention is a metal of groups IVBVIII of the periodic table as shown in The Handbook of Chem ...
Organometallic compound - Organometallic compound - Alkene and alkyne ligands: An alkene ligand contains a π bond between carbon atoms, C=C, which can serve as an electron pair donor in a metal complex, as in the case of Zeises salt (see above Historical developments). This complex may be prepared by bubbling ethylene, C2H4, through an aqueous solution of [PtCl4]2− in the presence of divalent tin, Sn(II), which aids in the removal of the chloride ion (Cl−) from the coordination sphere of the divalent platinum, Pt(II). The alkene ligand bonds to the metal centre by both electron donation and acceptance, similar to the situation with carbon monoxide. Electron donor-and-acceptor character between
The general name metallocene is derived from ferrocene, (C5H5)2Fe or Cp2Fe , systematically named bis(η5-cyclopentadienyl)iron(II). According to the IUPAC definition, a metallocene contains a transition metal and two cyclopentadienyl ligands coordinated in a sandwich structure, i. e., the two cyclopentadienyl anions are co-planar with equal bond lengths and strengths. Using the nomenclature of hapticity, the equivalent bonding of all 5 carbon atoms of a cyclopentadienyl ring is denoted as η5, pronounced pentahapto. There are exceptions, such as uranocene, which has two cyclooctatetraene rings sandwiching a uranium atom.. In metallocene names, the prefix before the -ocene ending indicates what metallic element is between the Cp groups. For example in ferrocene, iron(II) or ferrous is present.. In contrast to the more strict definition proposed by IUPAC, which requires a d-block metal and a sandwich structure, the term metallocene and thus the denotation -ocene, is applied in the chemical ...
f-Block Metallocene refers to a class of organometallic sandwich compounds with f-Block metal and electron-rich ligands like cyclopentadienyl anion. The first prepared and well-characterized f-block metallocenes were the tris(cyclopentadienyl) lanthanide complexes, (C5H5)3Ln (Ln = La, Ce, Pr, Nd, Sm and Gd). However, their significance is limited more to their existences and structures than to their reactivity. The cyclopentadienyl ligands of f-block metallocenes were considered as inert ancillary ligands, only capable of enhancing their stability and solubility, but not their reactivity. In addition, only late and small metals in the lanthanide series, i.e., elements from Sm to Lu, are trivalent metallocene complexes, [(C5H5)2LnZ]n In 1980, the pentamethylcyclopentadienyl ligand, C5Me− 5, was introduced to prepare the lanthanide complexes with all metals in the series. Apart from improving the stability and solubility of the complexes, it was demonstrated to participate in organometallic ...
Alfa Aesar™ Bis(cyclopentadienyl)titanium dichloride, 97% 250g Alfa Aesar™ Bis(cyclopentadienyl)titanium dichloride, 97% Betaj to Bisc -Organics
A bulky, optically active monoanionic scorpionate ligand, tris(4S-isopropyl-5,5-dimethyl-2-oxazolinyl)phenylborate (To P*), is synthesized from the naturally occurring amino acid l-valine as its lithium salt, Li[To P*] (1). That compound is readily converted to the thallium complex Tl[To P*] (2) and to the acid derivative H[To P*] (3). Group 7 tricarbonyl complexes To P*M(CO) 3 (M = Mn (4), Re (5)) are synthesized by the reaction of MBr(CO) 5 and Li[To P*] and are crystallographically characterized. The ν CO bands in their infrared spectra indicate that π back-donation in the rhenium compounds is greater with To P* than with non-methylated tris(4S-isopropyl-2-oxazolinyl)phenylborate (To P). The reaction of H[To P*] and ZnEt 2 gives To P*ZnEt (6), while To P*ZnCl (7) is synthesized from Li[To P*] and ZnCl 2. The reaction of To P*ZnCl and KOtBu followed by addition of PhSiH 3 provides the zinc hydride complex To P*ZnH (8). In this study, compound 8 is the first example of a crystallographically ...
In the complex salt [eta superscript 6]-1-chloro-2-(pyrrolidin-1-yl)benzene]-([eta superscript 5]-cyclopentadienyl)iron(II) hexafluoridophosphate, [Fe(C[subscript 5]H[subscript 5])-(C[subscript 10]H[subscript 12]CIN)]PF[subscript 6], (I), the complexed cyclopentadienyl and benzene rings are almost parallel, with a dihedral angle between their planes of 2.3 (3)°. In a related complex salt, ([eta superscript 5]-cyclopentadienyl){2-[[eta superscript 6]-2-(pyrrolidin-1-yl)phenyl]phenol}-iron(II) hexafluoridophosphate, [Fe(C[subscript 5]H[subscript 5])(C[subscript 16]H[subscript 17]NO)]PF[subscript 6], (II), the analogous angle is 5.4 (1)°. In both complexes, the aromatic C atom bound to the pyrrolidine N atom is located out of the plane defined by the remaining five ring C atoms. The dihedral angles between the plane of these five ring atoms and a plane defined by the N-bound aromatic C atom and two neighboring C atoms are 9.7 (8) and 5.6 (2)° for (I) and (II), respectively ...
Organometallic compounds composed of metal atoms and organic molecular rings have unique physical and chemical properties, and show attractive applications in optoelectronic devices, catalysts, biosensors and so on. In this paper, the structure and photoelectron spectra of a series of organometallic compounds Ln(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| (Ln = Ce, Eu, Ho, Nd and Yb) have been systematically studied by using two functional B3LYP and BPW91 based on the density functional theory. The results show organometallic complexes Ln(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| are typical sandwich structure. Both Eu(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| and Ho(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| have perfect sandwich structure with high D8h point symmetry. Nd(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| and Yb(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|/sub||sup|¯|/sup| possess D|sub|4h|/sub| point symmetry. Ce(C|sub|8|/sub|H|sub|8|/sub|)|sub|2|
The acquisition, analysis, and understanding of metal-ligand bond energy information in organometallic molecules is an active and important area of chemical research. This new volume presents a broad, up-to-date, and in-depth overview of the current state of knowledge in this field. It brings together carefully reviewed contributions from leading experimental researchers studying organometallic bonding energetics in the gas phase, in solution, and on well-characterized surfaces. The latest theoretical developments are also presented. In addition, an overview chapter provides an introduction to basic concepts and the various experimental methodologies employed, as well as an extensive bibliography of relevant review articles, textbooks, thermodynamic data compilations, and other source materials.Marks, Tobin J. is the author of Bonding Energetics in Organometallic Compounds with ISBN 9780841217911 and ISBN 0841217912. [read more] ...
Several cobalt complexes with tripodal chelating ligands Tp and Tp* (Tp = tris(pyrazolyl)borate; Tp* = tris(3,5-dimethyl-pyrazolyl)borate) were synthesized by treating the homoscorpionates of the first generation with CoBr2 under different conditions. These complexes were characterized with X-ray crystallographic determination as well as IR, NMR, MS, and UV-vis spectroscopies. Reaction of KTp with CoBr2 in THF afforded an unprecedented trinuclear Co(II) complex [TpCo(Hpz)Br]2(CoBr2) (1) with Tp as terminal ligands, as well as an oxidized side-product (Tp2Co)(Co2Br6) (2). The terminal Co(II) centers of (1) are octahedrally coordinated while the Co(II) in the bridging unit has a distorted tetrahedral geometry, holding a neighboring Co···Co distance of 3.472 Å. Reaction of KTp* with CoBr2 afforded half-sandwich Tp*CoBr (4) with pseudotetrahedrally coordinated Co(II) center, which is accessible to other donors. Mononuclear Tp*CoSPh (7) and dinuclear (Tp*Co)2O2(pz)2 (8) were prepared through ...
A carbon ignition temperature depressing agent is disclosed along with a method of regenerating an automotive particulate trap using the ignition temperature depressing agent. The agent is effective to promote oxidation of on-board collected carbonaceous particles extracted from the automobile exhaust. The agent comprises (a) an organometallic compound that upon heating (the combustion process of the engine) forms a readily reducible metal oxide which when finely divided promotes a carbonaceous ignition temperature in the range of as low as 450 F. and up to as low as 675 F., and (b) an aerosol-promoting liquid carrier effective to form a fine mist with the organometallic compound when sprayed, the carrier having a boiling point in the range of 176 -302 F. (80 -150 C.). The organometallic compound is one or more metal octoates having the metal selected from the group consisting of copper, nickel and cerium. The organometallic compounds are readily soluble and stable in the fuel supply used with an
Organometallic chemistry, rigorously defined by the chemical synthesis and reactivity of molecules with metal-carbon bonds, is a vibrant area of research with a large variety of practical applications [1]. For example, organometallic complexes are commonly used as catalysts for the production of commodity chemicals, materials such as polymers, and in fine chemical synthesis and medicinal chemistry discovery [1,2]. The majority of discoveries in the area have been performed in the solution phase, with studies in the solid state generally often reserved only for structural analysis; for example, single-crystal X-ray crystallography and, to a significantly lesser extent, solid-state nuclear magnetic resonance spectroscopy. By contrast to the solution phase, studies on the synthesis of, and catalysis using, organometallic complexes in the solid phase have attracted significantly less attention, even though there are potential benefits to this approach, such as: improved selectivities in synthesis ...
Applied Homogeneous Catalysis with Organometallic Compounds | Boy Cornils, Wolfgang A. Herrmann | download | B-OK. Download books for free. Find books
Accelerators that can be useful for an energy polymerizable composition comprising a cationically curable material; energy polymerizable compositions comprising at least one cationically curable material and an initiation system therefor, the initiation system comprising at least one organometallic complex salt and at least one accelerator; and a method for curing the compositions. The cured compositions can provide useful articles. The invention also provides compositions of matter comprising an organometallic complex salt and at least one compound selected from the Class 1 through Class 4 compounds disclosed herein.
The three organometallic complexes [(Cis-Pt^II (DDH) (2,5- Dihidroxibenzensulfonic)^2, Rh^I (CO)2 Cl(2- Aminobenzothiazole) and Rh^I (CO)2 Cl(5-Cl-2- Methilbenzothiazole)] used in this study had been previously found to have a high in vitro activity against promastigote and amastigote like forms of Leishmania donovani. Here, the cytotoxic effect of these new organometallic complexes on the J-774 macrophages were studied. Only the Rh^I(CO)2 Cl (2-Aminobenzothiazole) complex induced substantial toxicity in the cells.. Also, we assayed the effect of this complex on the parasite s biosynthesis of macromolecules. The Rh^I(CO)2Cl (5-Cl-2- Methylbenzothiazole) complex inhibited DNA, RNA, and protein synthesis. On the other hand, the two other compounds tested did not inhibit the incorporation of radioactive precursors. Finally important ultrastructural alterations in the parasites treated with the two non-cytotoxic complexes were observed ...
16. R.W. Schurko, Simon Fraser University, January 25, 2006. Observing the Invisible Nucleus: NMR of unreceptive nuclei in inorganic, organometallic and other solid materials.. 15. R.W. Schurko. National Research Council, Ottawa. October 20, 2005. NMR of unreceptive nuclei in solid materials: developments and applications.. 14. R.W. Schurko. University of Western Ontario, October 5, 2005. Solid-state NMR across the periodic table: Applications to organometallic and inorganic materials.. 13. R.W. Schurko. University of Ottawa, September 16, 2005. Solid-State NMR across the periodic table: Applications to organometallic and inorganic materials.. 12. R.W. Schurko. Michigan State University, Sept. 27, 2004. Solid-State NMR of Quadrupolar Nuclei in Organometallic Complexes, Mesoporous Composite Materials & Nanoparticles, a talk by R.W. Schurko.. 11. R.W. Schurko. University of Manitoba, Sept. 17, 2004. Solid-State NMR of Quadrupolar Nuclei in Organometallic Complexes, Mesoporous Composite Materials & ...
16. R.W. Schurko, Simon Fraser University, January 25, 2006. Observing the Invisible Nucleus: NMR of unreceptive nuclei in inorganic, organometallic and other solid materials.. 15. R.W. Schurko. National Research Council, Ottawa. October 20, 2005. NMR of unreceptive nuclei in solid materials: developments and applications.. 14. R.W. Schurko. University of Western Ontario, October 5, 2005. Solid-state NMR across the periodic table: Applications to organometallic and inorganic materials.. 13. R.W. Schurko. University of Ottawa, September 16, 2005. Solid-State NMR across the periodic table: Applications to organometallic and inorganic materials.. 12. R.W. Schurko. Michigan State University, Sept. 27, 2004. Solid-State NMR of Quadrupolar Nuclei in Organometallic Complexes, Mesoporous Composite Materials & Nanoparticles, a talk by R.W. Schurko.. 11. R.W. Schurko. University of Manitoba, Sept. 17, 2004. Solid-State NMR of Quadrupolar Nuclei in Organometallic Complexes, Mesoporous Composite Materials & ...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
Nickelocene is the organonickel compound with the formula Ni(η5-C5H5)2. Also known as bis(cyclopentadienyl)nickel or NiCp2, this bright green paramagnetic solid is of enduring academic interest, although it does not yet have any known practical applications. Ni(C5H5)2 belongs to a group of organometallic compounds called metallocenes. Metallocenes usually adopt structures in which a metal ion is sandwiched between two parallel cyclopentadienyl (Cp) rings. In the solid-state, the molecule has D5h symmetry, wherein the two rings are eclipsed. The Ni center has a formal +2 charge, and the Cp rings are usually assigned as cyclopentadienyl anions (Cp−), related to cyclopentadiene by deprotonation. The structure is similar to ferrocene. In terms of its electronic structure, three pairs of d electrons on nickel are allocated to the three d orbitals involved in Ni-Cp bonding: dxy, dx2-y2, dz2. One of the two remaining d-electrons resides in each of the dyz and dxz orbitals, giving rise to the ...
Any two L and/or A ligands may be bridged to each other. The metallocene compound may be full-sandwich compounds having two or more ligands L, which may be cyclopentadienyl ligands, cyclopentadiene derived ligands or substituted cyclopentadienyl ligands, or half-sandwich compounds having one ligand L, which is a cyclopentadienyl ligand or heteroatom substituted cyclopentadienyl ligand or hydrocarbyl substituted cyclopentadienyl ligand such as an indenyl ligand, a benzindenyl ligand or a fluorenyl ligand and the like or any other ligand capable of T, bonding to a transition metal atom (M). One or more of these bulky ligands is K -bonded to the transition metal atom. Each L can be substituted with a combination of substituents, which can be the same or different including hydrogen or a linear, branched or cyclic alkyl, alkenyl or aryl radicals for example. The metal atom (M) may be a Group 4, 5 or 6 transition metal or a metal from the lanthanide and actinide series, preferably the transition ...
United States Patent Ofi 3,103,525 Patented Sept. 10, 1963- PROCESS FOR HYDROGENATING IRON SUB- GROUP METAL CYCLOPENTADENYL COM- POUNDS Thomas H. Coflield, Heidelberg, Germany, and Kryn G. lhrman, Farmington, Mich, assignors to Ethyl Corporation, New York, N.Y., a corporation of Virginia N Drawing. Filed Sept. 18, 1959, Ser. No. 840,79 11 Claims. (Cl. 260-429) This invention relates to a chemical process for preparing organometallic compounds. More specifically, this invention relates to a process for forming organometallic compounds in which an aromatic-metal-cyclopentadienyl compound is reduced to form a compound in which both an aromatic molecule and a cyclopentadiene molecule are bonded to the metal atom. An object of this invention is to provide a process for forming organometallic compounds. A furtherobject is to provide a new process in which an aromaticmetalscyclopentadienyl compound, either neutral orionic, is reacted with reducing agent to form compounds (in which both an aromatic ...
The past 15 years have witnessed tremendous advances in the design and use of organometallic complexes as precatalysts for olefin polymerization. Most recently, an intense search has been started in next-generation single-site catalysts. New approaches have been taken to ligand design.
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Extinguishing media: Use agent most appropriate to extinguish fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam ...
The main target of this thesis is the design of a new aluminum-based surface ligand with low coordination and expected high acidity. These new supports will serve for the immobilization of different organometallic complexes with the surface organometallic chemistry (SOMC). The resulting molecular like species will be used for various catalytic applications including alkane metathesis, olefin metathesis and polymerization. The first chapter is an introduction to the field of catalysis, more specifically, surface organometallic with a summary of its concept and the main examples cited for the immobilization of transition metal complexes on different oxide surfaces (silica, silica-alumina and alumina). This chapter presents, as well, an overview of the use of the aluminum alkyls compounds and their immobilization on a surface for the generation of various aluminum based surfaces. The Second chapter details the reaction involving the grafting of the monomeric triisobutylaluminum on SBA-15700. The ...
Ivânia R. Cabrita, Pedro R. Florindo, Paulo J. Costa, M. Conceição Oliveira, Ana C. Fernandes, (2018). Hydrophosphonylation of aldehydes catalyzed by cyclopentadienyl ruthenium(II) complexes. Molecular Catalysis, 450, 77-86. ISSN 2468-8231. eISSN . http://dx.doi.org/10.1016/j.mcat.2018.03.001 ...
Quantum chemistry calculations showed that the first reduction, as experimentally observed by cyclic voltammetry for a series of neutral and cationic functionalised bis(cyclopentadienyl) titanium(iv) derivatives, is metal based, involving the chemically and electrochemically reversible TiIV/TiIII redox couple. The
McLennan, Alistair J. (1983) Cyclopentadienyl platinum complexes and organic group transfer reactions. PhD thesis, University of Glasgow. Full text available as ...
The title complex salt, [Fe(C[subscript 5]H[subscript 5])(C[subscript 13]H[subscript 10]S[subscript 2])]PF[subscript 6][middle dot]0.33C[subscript 3]H[subscript 6]O, obtained from an acetone-diethyl ether-dichloromethane mixture at 280 (2) K, has three cationic molecules (A-C), three hexafluoridophosphate counter-anions and one acetone solvent molecule in the asymmetric unit. Two of the three cations contain FeCp (Cp is cyclopentadienyl) inside the fold of the heterocycle. The dihedral angles between the planes of the external (complexed and uncomplexed) benzene rings in the thianthrene molecule are 146.5 (2)° for FeCp-out-of-fold molecule A, and 139.0 (3) and 142.5 (2)° for the two FeCp-infold molecules B and C, respectively. The complexed Cp and benzene rings in each molecule are almost parallel, with a dihedral angle between the planes of 0.2 (5)° for molecule A, 2.8 (5)° for B, and 2.19 (4) and 6.86 (6)° for the disordered Cp ring in C ...
Novel 3-O-1,2;5,6-di-O-isopropylidene-alpha-D-glueofuranose] and 3-O-D-glucose] derivatives with an iminodiacetate (N,O,O), a histidinate, and an N-(acetetyl)picolylamine (N,N,O) chelating system for tridentate coordination of the organometallic M(CO)(3)-fragment (M = Tc, Re) have been prepared. The chelates were introduced and assembled through reductive amination starting from 3-O-1,2;5,6-di-O-isopropylidene-alpha-D-glucofuranose]-acetaldehyde. After deprotection, the pyranose derivatives were reacted with the precursor NEt4](2)ReBr3(CO)(3)] to afford the corresponding organometallic complexes in yields between 54% and 94%. The NMR, MS, and IR analyses corroborated the tridentate coordination of the organometallic metal center exclusively via the synthetic chelates. In the case of the N-(acetyl)picolylamine derivative, the coordinative properties were further confirmed by X-ray structure analysis of the first Re(CO)(3)-D-glucofuranose complex. All glucose complexes unveiled good stability and ...
COMMUNICATIONS A. K. Beck. D.A. Plattner, F. N. M. Kuhnle, J. Org. Chem. 1995,60,17881799. [8] D.Seebach. D.A. Plattner, A.K. Beck, Y. M. Yang, D. Hunziker, Hefv. Chim. Acta 1992.75,2171-2209. [9]Review: K. Mikami in Encyclopedia of Reagents for Organic Synthesis, Vol. I (Ed.: L. A. Paquette), Wiley, Chichester, UK, 1995,p. 407;C. A. Martin, Ph. D. Thesis Massachusetts Institute of Technology, Cambridge, MA, USA. 1988:J. T. Wang, X. Fan, X. Feng, Y. M. Qian, Synthesis 1989,291292: G.E. Keck, K. H. Tarbet, L. S. Geraci, J. Am. Chem. Soc. 1993,115, 8467-8468: K. Mikami. S. Matsukawa, Tetrahedron: Asymmetry 1995, 6, 2571 -2574:J. W. Faller, D. W. Sams, X. Liu. J. Am. Chem. Soc. 1996,118, 1217-1218: S. Weigand, R. Brtickner, Chenr. EUKJ. 1996, 2,1077-1084. [lo] K. Mikami, S. Matsukawa. Nature 1997,385,613-615; M. Mori, H. Imma, N. Takai, Tetrahedron Letr.1997, 38, 6229-6232. [ll] See Ref. [lot and for a similar (R)-3,3,5,S-tetrachloro-4.4,6,6-tetramethylbiphenol, see: E. J. Corey, M. A. Letavic. M. ...
Chemische Bezeichnung oder Material: 3-Methoxyphenylmagnesium bromide Anmerkung zur Bezeichnung: 1M solution in THF/toluene CAS.: 36282-40-3 CAS Min. %.: 19.02 CAS Max. %.: 23.25 CAS_: 109-99-9 CAS Min. %_: 76.75 CAS Max. %_: 80.98 CAS: 108-88-3 Summenformel: C7H7BrMgO Strukturformel: CH3OC6H4MgBr Molare Masse: 211.34 MDL-Nummer: MFCD00672002 800ML 3-Methoxyphenylmagnesiumbromid, 1M Lösung in THF/Toluol, AcroSeal ...
Although phosphorus containing ligands are commonly employed for enantioselective catalysis as components of organometallic complexes, recent years have seen a steady growth in the use of non-organometallic phosphorus reagents for similar applications. This review highlights some of the recent literature in this area to dare, with particular reference to asymmetric reduction and to C-C and C-N bond forming reactions. The review also serves to highlight some areas of potential future development.. ...
Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on small chemical compounds.
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
Spectroscopic Properties of Inorganic and Organometallic Compounds: Volume 13 Spectroscopic Properties of Inorganic and Organometallic Compounds: Volume 13 ...
This thesis sets out to explore the electronic structures and redox properties of organometallic complexes. The mixed valence states of these complexes have been investigated and classified. Chapter 1 introduces the general area and provides a brief summary of the theory to electron transfer. The concepts discussed in Chapter 1 are developed further in subsequent Chapters. A trimetallic molecular assembly featuring two redox-active organoiron fragments connected via a central ruthenium tetramesitylporphyrin socket through pendant pyridyl moieties was investigated using electrochemical and UV-vis-NIR/IR spectroelectrochemical studies. Electrochemical studies reveal three reversible oxidation waves, the first two of which can be attributed to the stepwise oxidation of the iron centres. The redox separation between these iron redox waves was found to be constant regardless of electrolyte composition, suggesting a through bond mechanism for electronic interactions between the iron centres. An ...
The use of transition organometallic complexes as reagents for the synthesis of complex organic molecules has been under intensive growth and development for several decades, and many organic transformations of profound synthetic potential has been achieved. Particularly, the use of organoiron complexes has been recognized as a powerful tool in the synthetic methodology due to their ability to react with nucleophiles and electrophiles in a stereoselective fashion. The use of NMO as a chemoselective, metal mediated oxidizing agent will be discussed.
Diametrically opposed Carbenes on an α-Cyclodextrin : synthesis, characterization of organometallic complexes and Suzuki-Miyaura coupling in ethanol and in water, Eur. J. Org. Chem. 2013, DOI : 10.1002/ejoc.201300268. ...
Special topics in catalysis such as adsorption, catalyst preparation, homogeneous catalysis, inorganic and organometallic complexes as catalysts, mechanism of catalytic reactions, oxidation catalysis, will be studied as literature projects. The subjects of choice are based on the relevance for the ongoing research in the group. ...
Research has continued into time-resolved spectroscopic and low-temperature matrix isolation studies on transient intermediates involved in the reaction mechanisms of organometallic complexes. In order to utilise the synthetic capabilities of organometallics to an even greater extent it is essential to gain a better understanding of how they act as catalysts or synthetic
Synthetic Stratagies to Optimize Photophysical and Photoredox Properties of Organometallic Complexes. **Friday, October 20, 2017 @ 3:00 PM in NSC 228 (refreshments 2:30 PM in NSC 306) ...
TY - JOUR. T1 - Effects of treatment with a carbon monoxide-releasing molecule and a heme oxygenase 1 inducer in the antinociceptive effects of morphine in different models of acute and chronic pain in mice. AU - Hervera, Arnau. AU - Gou, Gemma. AU - Leánez, Sergi. AU - Pol, Olga. PY - 2013/8/1. Y1 - 2013/8/1. N2 - Rationale: Treatment with a carbon monoxide-releasing molecule (tricarbonyldichlororuthenium(II) dimer, CORM-2) or a classical heme oxygenase 1 inducer (cobalt protoporphyrin IX, CoPP) has potent anti-inflammatory effects, but the role played by these treatments in the antinociceptive effects of morphine during acute and chronic pain was not evaluated. Objectives: In wild type (WT), neuronal (NOS1-KO), or inducible (NOS2-KO) nitric oxide synthases knockout mice, we evaluated the effects of CORM-2 and CoPP treatments in the antinociceptive actions of morphine and their interaction with nitric oxide during acute, visceral, and chronic inflammatory or neuropathic pain. Methods: Acute ...
387501517 - EP 0983983 A3 2000-07-05 - Combinatorial synthesis and analysis of organometallic compounds and catalysts - [origin: EP0978499A2] Methodologies for the synthesis, screening and characterisation of organometallic compounds and catalysts (eg homogenous catalysts), including combinatorial synthesis, screening and characterisation of libraries of supported and unsupported organometallic compounds and catalysts (eg homogenous catalysts). The methods can be applied to the preparation and screening of large numbers of organometallic compounds which can be used not only as catalysts (eg homogeneous catalysts), but also as additives and therapeutic agents.[origin: EP0978499A2] Methodologies for the synthesis, screening and characterisation of organometallic compounds and catalysts (eg homogenous catalysts), including combinatorial synthesis, screening and characterisation of libraries of supported and unsupported organometallic compounds and catalysts (eg homogenous catalysts). The methods can be
Medicinal plants are increasingly being projected as suitable alternative source for the treatment of various diseases. However, toxic effects resulting from therapeutic bismuth compounds are still documented in animals and humans. This study described the genetic effects of five common lichen species and compared their activities on the genotoxicity induced by the colloidal bismuth subcitrate. After the application of colloidal bismuth subcitrate and lichen extracts, separate and together, human whole blood cultures were assessed by sister-chromatid exchange (SCE) and micronucleus tests. According to our results, the frequencies of SCE and micronucleus rate in peripheral lymphocytes were significantly increased by colloidal bismuth subcitrate (at dose 5 mu g/mL) compared with controls. However, lichen extracts had no genotoxic effect. The order of anti-genotoxicity efficacy against colloidal bismuth subcitrate was Pseudevernia furfuracea, Dermotocarpon intestiniforme, Ramalina capitata, ...
Reaction of Organic Halogen Compounds with Metals (Part Ⅰ) A Formation of Organometallic Complex in Dimethyl Formamide Solvent Reaction of organic chlorine containing ester, alcohol, and acids with metallic tin and zinc in dimethyl formamide solvent gave a good yield of organo metallic complex. The same reaction under a mixed U.V. irradiation could not give an appreciable yield of the complex except in the case of an elevated reaction temperature. The solvation effect of dimethyl formamide of the metallic complex formation was markedetly increased as compared to the reaction in toluene and cyclohexane. In case of chlorine containing carboxylic acid, the formation of organo chloro zinc complex of the salt was observed. The reaction of organo zinc complex with a carbonyl precursor gave the addition product together with a dimerized product. Especially the aldehyde species enhanced the formation of zinc complex. The addition reaction was simple and convenient, but the yield was not high.(30-40% for
CO and 4 of the CORMs (ALF 153, 157, 436 and CORM-2) increased cGMP levels in smooth muscle cells, while the rest of the compounds failed to alter cGMP production. The CORM-stimulated increase was minor (50-300% over basal) compared to the effects seen with the NO-donor, SNP (at least 100-fold). CORM-3, a widely used CORM, decreased basal cGMP levels in RASMC. Interestingly, CO and CORMs modestly reduced SNP-stimulated cGMP formation in RASMC. The inactive forms of CORMs (compounds lacking the ability to liberate CO) did not affect SNP-induced cGMP accumulation. CORMs also reduced bradykinin-stimulated cGMP levels in endothelial-smooth muscle co-cultures. In sGC activity assays using purified recombinant human sGC, CORMs were ineffective in stimulating cGMP production. However, CORMs blocked up to 80% of DEA-NO-induced sGC activity. ...
Zinc phthalocyanines (ZnPc) are currently being investigated in relation to their use as sensitisers for Photodynamic Therapy (PDT). In particular, the photophysical properties of these dyes are of interest since then- ability to generate the cytotoxic species, singlet oxygen ((^1)O(_2)), is believed to be central to their role in causing tumour necrosis. In this study, a detailed investigation of the photophysical properties of substituted zinc phthalocyanines under various conditions is described. Two novel β-tetra substituted zinc phthalocyanines have been synthesised, ZnPc(CMe(C0(_2)Me)(_2))(_4) and ZnPc(CHMeCO(_2)H)(_4). The nature of peripheral substituents has little effect on triplet state or singlet oxygen production by ZnPc, however, ZnPc(CHMeCO(_2)H)(_4) displays a remarkable sensitivity to the ionic strength of non aqueous solutions. Ion concentrations below 10(^-4) mol dm(^-3) induce dimerisation whilst concentrations greater than this promote monomerisation. This behaviour is ...
View more ,We sought to investigate the T1 kinetics of blood and myocardium after three infusion schemes of gadobenate dimeglumine (Gd‐BOPTA) and subsequently compared contrast‐enhanced whole‐heart coronary MRI after a bolus Gd‐BOPTA infusion with nonenhanced coronary MRI at 1.5 T. Blood and myocardium T1 was measured in seven healthy adults, after each underwent three Gd‐BOPTA infusion schemes (bolus: 0.2 mmol/kg at 2 mL/sec, hybrid: 0.1 mmol/kg at 2 mL/sec followed by 0.1 mmol/kg at 0.1 mL/sec, and slow: 0.2 mmol/kg at 0.3 mL/sec). Fourteen additional subjects underwent contrast‐enhanced coronary MRI with an inversion‐recovery steady‐state free precession sequence after bolus Gd‐BOPTA infusion. Images were compared with nonenhanced T2‐prepared steady‐state free precision whole‐heart coronary MRI in signal‐to‐noise ratio, contrast‐to‐noise ratio, depicted vessel length, vessel sharpness, and subjective image quality. Bolus and slow infusion schemes resulted in ...
A metallocene catalyst is provided which comprises the product obtained by combining (a) a metallocene procatalyst, preferably one containing a bridging group possessing at least two bulky groups, and (b) a cation-generating cocatalyst. A process for activating a metallocene procatalyst is also provided which comprises combining the metallocene procatalyst with the components of a cation-generating cocatalyst.
TY - JOUR. T1 - Focal liver lesions. T2 - Evaluation of the efficacy of gadobenate dimeglumine in MR imaging - A multicenter phase III clinical study. AU - Petersein, Jan. AU - Spinazzi, Alberto. AU - Giovagnoni, Andrea. AU - Soyer, Philippe. AU - Terrier, Francois. AU - Lencioni, Riccardo. AU - Bartolozzi, Carlo. AU - Grazioli, Luigi. AU - Chiesa, Antonio. AU - Manfredi, Riccardo. AU - Marano, Pasquale. AU - Van Persijn Van Meerten, Els L.. AU - Bloem, Johannes L.. AU - Petre, Carina. AU - Marchal, Guy. AU - Greco, Alina. AU - McNamara, Michael T.. AU - Heuck, Andreas. AU - Reiser, Maximilian. AU - Laniado, Michael. AU - Claussen, Claus. AU - Daldrup, Heike E.. AU - Rummeny, Ernst. AU - Kirchin, Miles A.. AU - Pirovano, Gianpaolo. AU - Hamm, Bernd. PY - 2000/6. Y1 - 2000/6. N2 - PURPOSE: To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR)imaging of focal liver lesions. MATERIALS AND METHODS: In 126 of 214 patients, MR imaging was performed before ...
Alfa Aesar™ Bis(cyclopentadienyl)vanadium bromide, 98% 1g; Ampoule Alfa Aesar™ Bis(cyclopentadienyl)vanadium bromide, 98% Betaj to Bisc -Organics
Table of Contents for 2016 Global and Chinese Cyclopentadienyl Manganese Tricarbonyl (CAS 12079-65-1) Industry Market Research Report by Prof Research Available at market-research-reports.com.
Bismuth Subcitrate - Get up-to-date information on Bismuth Subcitrate side effects, uses, dosage, overdose, pregnancy, alcohol and more. Learn more about Bismuth Subcitrate
This invention uses a new method of producing ionic metallocene compounds. These compounds are useful as catalysts for polymerization of olefins, primarily propylene. This method uses an ionizing agent which ionizes the neutral metallocene compound. The ionizing ionic compound does not contain an active proton and contains a carbonium, oxonium or sulfonium cation. The anion of the ionizing ionic compound is not coordinated or is only loosely coordinated to the metallocene cation and is chemically unreactive with the metallocene cation. Examples of such compounds are triphenylcarbenium tetrakis(pentafluorophenyl)boronate, triphenylcarbenium tris(pentafluorophenyl)phenyl boronate and triphenylcarbeniumtris(pentafluorophenyl)4-trimethylsilyl-2,3,5,6-tetrafluorophenylboronate. The process of making catalysts with this invention produces catalysts having high activity and does not produce by-products which can inhibit catalyst activity. This new synthesis is a clean reaction which does not produce a Lewis
387498759 - EP 0976784 A4 2001-01-03 - METAL/RUBBER ADHESION PROMOTER AND RUBBER COMPOSITION - [origin: WO9942519A1] An adhesion promoter which is equal or superior in adhesiveness to an organocobalt compound and has improved storage stability; and a rubber composition containing the adhesion promoter. The adhesion promoter, which enhances adhesion between a steel cord and a rubber material, comprises an organometallic compound containing nickel and an organometallic compound containing zinc. The rubber composition comprises 100 parts by weight of a rubber ingredient and 0.1 to 10.0 parts by weight of the adhesion promoter.[origin: WO9942519A1] An adhesion promoter which is equal or superior in adhesiveness to an organocobalt compound and has improved storage stability; and a rubber composition containing the adhesion promoter. The adhesion promoter, which enhances adhesion between a steel cord and a rubber material, comprises an organometallic compound containing nickel and an organometallic compound
Emissive phosphorescent organometallic compounds are described that produce improved electroluminescence, particularly in the blue region of the visible spectrum. Organic light emitting devices employ
|i|Purpose|/i|. Retrospective comparison between gadofosveset trisodium and gadobenate dimeglumine steady state magnetic resonance angiography (SS-MRA) of the thoracic vasculature at 1.5T using signal-to-noise ratio (SNR) and vessel edge sharpness (ES) as markers of image quality. |i|Materials and Methods|/i|. IRB approval was obtained. Twenty separate patients each underwent SS-MRA using high-resolution 3D ECG-triggered coronal IR-TFE at 1.5T approximately 3-4 minutes following 10 or 15 mL gadofosveset or 20 mL gadobenate. ROIs were placed in the right atrium, left ventricle, left atrium, ascending aorta, descending aorta, and right pulmonary artery to estimate SNR. Vessel ES was estimated as 20-80% rise distances from line intensity profiles in the left pulmonary vein, ascending aorta, and descending aorta. Data were analyzed using nonpaired Students |svg xmlns:xlink=http://www.w3.org/1999/xlink xmlns=http://www.w3.org/2000/svg style=vertical-align:-0.11285pt;width:5.9250002px; id=M1 height=
Carbohydrate - metallocene conjugates. Metallocenes are organometallic compounds characterized by a transition metal central atom (M) bound to cyclopentadienide (Cp-/C5H5-) ligands, the general formula of metallocenes being Cp2M. Titanocene dichloride was among the first non-platinum organometallics investigated as promising anticancer agents. Although its clinical trials were stopped because of low efficacy and other drawbacks, the last two decades have witnessed renewed research interest in anticancer metallocenes. We have started a programme aimed at improving cytotoxic activity and pharmacological properties of metallocenes by their conjugation to carbohydrates, iminosugars and selected heterocycles. Carbohydrates and iminosugars have typicaly 3 - 6 functional groups that can be modified to ameliorate cytotoxic profile, bioavailability, solubility, biocompatibility, and hydrophobic/hydrophilic balance of the resulting metallocene-carbohydrate conjugate. Recently, we have extended this ...
This Thesis is dedicated to the synthesis and investigation of the rare-earth metal complexes with two particular types of chelating monoanionic ligand systems: • ortho-deprotonated N,N-dimethyl-benzylamines (dmba)- • cyclopentadienyl-phosphazenes (CpPN)- The first ligand system is presented by a series of side-chain modified (dmba)- ligands that have been used to study the influence of present or absent benzylic protons on the stability of homoleptic rare-earth metal tris-aryl complexes. Discussion of their synthesis, thermal stability and crystal structures composes Chapter II. The second and novel ligand system is presented by a series of CpPN-ligands with different substituents on P- and N-atoms and at the Cp-ring. A discussion of their syntheses, prototropic equilibria and molecular structures is presented in Chapter III. Cyclopentadienyl-phosphoranes are the intermediates in the CpPN ligand synthesis. Thus a new highly crowded cyclopentadienyl-phosphane skeleton, some mechanistic ...
This Thesis is dedicated to the synthesis and investigation of the rare-earth metal complexes with two particular types of chelating monoanionic ligand systems: • ortho-deprotonated N,N-dimethyl-benzylamines (dmba)- • cyclopentadienyl-phosphazenes (CpPN)- The first ligand system is presented by a series of side-chain modified (dmba)- ligands that have been used to study the influence of present or absent benzylic protons on the stability of homoleptic rare-earth metal tris-aryl complexes. Discussion of their synthesis, thermal stability and crystal structures composes Chapter II. The second and novel ligand system is presented by a series of CpPN-ligands with different substituents on P- and N-atoms and at the Cp-ring. A discussion of their syntheses, prototropic equilibria and molecular structures is presented in Chapter III. Cyclopentadienyl-phosphoranes are the intermediates in the CpPN ligand synthesis. Thus a new highly crowded cyclopentadienyl-phosphane skeleton, some mechanistic ...
0029]Aspects of the present disclosure relate to a process which comprises treating a Type I titanyl phthalocyanine with a weak acid having a pKa of at least equal to or greater than about -0.25, dissolving the weak acid treated Type I titanyl phthalocyanine in a solution comprising a trihaloacetic acid and an alkylene halide; adding the mixture comprising the dissolved Type I titanyl phthalocyanine to a solution comprising an alcohol and an alkylene halide thereby precipitating a Type Y titanyl phthalocyanine; treating the Type Y titanyl phthalocyanine with monohalobenzene thereby resulting in a high sensitivity titanyl phthalocyanine; a process wherein the weak acid pKa is from about 0 to about 15, and wherein the weak acid captures the metallic impurities present in the titanyl phthalocyanine Type I; a process where the weak acid pKa is from about 1 to about 10, and wherein the titanyl phthalocyanine obtained is Type V titanyl phthalocyanine; a process where the acid pKa is from about 2 to ...
We report the synthesis and analysis of metallocenes (ferrocene, chromocene, ruthenocene, vanadocene, tungstenocene-dihydride) encapsulated in single wall carbon nanotubes (SWNTs). In the case of ferrocene, efficient filling of the SWNTs was accomplished from both the liquid and the vapor phase. The other two metallocenes were filled from the vapor phase. High resolution transmission electron microscopy reveals single molecular chains of metallocenes inside SWNTs. Molecules move under the electron beam in the SWNTs indicating the absence of strong chemical bonds between each other and the SWNT wall. Their movement freezes after short illumination as a result of irradiation damage. Energy dispersive X-ray spectrometry confirms the presence of iron, chromium, ruthenium, vanadium and tungsten.
Extract] Significant recent attention has been devoted to the development of useful self-assembled hybrid materials.[1] This is particularly the case for metal-organic frameworks (MOFs), which display properties such as regularity, porosity, robustness, and high surface area that lead to potential applications in areas such as catalysis, gas separation, and storage.[2, 3] Our research groups and others have been developing new methods for the synthesis of both discrete and extended metal-organic materials, with particular interest in the controlled generation of increased structural complexity.[4] Herein we report a hierarchical self-assembly strategy which has been used to synthesize a new metal-organic framework. This strategy differs from the commonly employed molecular building block (MBB) and secondary building unit (SBU) approaches, where single metal ions or small inorganic clusters (polyhedra) are linked by bridging (often carboxylate) ligands in a one-pot reaction.[5] In these ...
|p|The development of two 1,8-napthalimide-conjugated Ru(|sc|ii|/sc|)-polypyridyl complexes which exhibit different DNA binding and photocleavage behavior is presented.|/p|
Gadoterate meglumine(Dotatrem) generic is a gadolinium based contrast agent, prescribed for visualization of brain along with with magnetic resonance imaging (MRI).
TY - JOUR. T1 - Interface-induced growth of boronate-based metal-organic framework membrane on porous carbon substrate for aqueous phase molecular recognition. AU - Liu, Schucheng. AU - Shinde, Sudhirkumar. AU - Pan, Jianming. AU - Ma, Yue. AU - Pan, Guoqing. PY - 2017/9/15. Y1 - 2017/9/15. N2 - For metal-organic frameworks (MOFs), introduction of special functional groups and integration on porous support will endow the MOF with specific molecular affinity and tunable membrane-like surface properties. Herein, we demonstrated a facile interface-induced Zn(II)-ligand-fragment co-assembly strategy to in situ fabricate boronate-based MOF membrane on hydrophobic porous carbon substrate for specific molecular recognition and separation. Due to the phenylboronic acid groups and hydrophobic porous carbon supporting layer, a catechol-containing medicinal natural flavone Luteolin was found to be efficiently and selectively recognized on the MOF composite in water-containing solution. As compared to the ...
Learn about the potential side effects of gadoterate meglumine. Includes common and rare side effects information for consumers and healthcare professionals.
Read the side effects of Gadoterate meglumine as described in the medical literature. In case of any doubt consult your doctor or pharmacist.
All 5 carbon atoms of a Cp ligand are bound to the metal in the vast majority of M-Cp complexes. This bonding mode is called η5-coordination. The M-Cp bonding arises from overlap of the five π molecular orbitals of the Cp ligand with the s, p, and d orbitals on the metal. This π bonding is significant, hence these complexes are referred to as π-complexes. Almost all of the transition metals, that is, group 4 to 10 metals, employ this coordination mode.[1]. In relatively rare cases, Cp binds to metals via only one carbon center. These types of interactions are described as σ-complexes because they only have a σ bond between the metal and the cyclopentadienyl group. Typical examples of this type of complex are group 14 metal complexes such as CpSiMe3. An example of both is (Cp2Fe(CO)2).. It is probable that η1-Cp complexes are intermediates in the formation of η5-Cp complexes. Still rarer, the Cp unit can bond to the metal via a three-carbons. In these η3-Cp complexes, the bonding ...
TY - JOUR. T1 - Chemistry. T2 - Gas adsorption sites in a large-pore metal-organic framework. AU - Rowsell, Jesse L.C.. AU - Spencer, Elinor C.. AU - Eckert, Juergen. AU - Howard, Judith A.K.. AU - Yaghi, Omar M.. PY - 2005/8/26. Y1 - 2005/8/26. N2 - The primary adsorption sites for Ar and N2 within metal-organic framework-5, a cubic structure composed of Zn4O(CO2) 6 units and phenylene links defining large pores 12 and 15 angstroms in diameter, have been identified by single-crystal x-ray diffraction. Refinement of data collected between 293 and 30 kelvin revealed a total of eight symmetry-independent adsorption sites. Five of these are sites on the zinc oxide unit and the organic link; the remaining three sites form a second layer in the pores. The structural integrity and high symmetry of the framework are retained throughout, with negligible changes resulting from gas adsorption.. AB - The primary adsorption sites for Ar and N2 within metal-organic framework-5, a cubic structure composed of ...
RESULTS: One hundred fourteen of 123 enrolled patients successfully underwent both examinations. Final diagnoses were intra-axial tumors, metastases, extra-axial tumors, other tumors, and nontumor (49, 46, 8, 7, and 4 subjects, respectively). Readers 1, 2, and 3 demonstrated preference for gadobenate dimeglumine in 46 (40.7%), 54 (47.4%), and 49 (43.0%) patients, respectively, compared with 6, 7, and 7 patients for gadobutrol (P , .0001, all readers). Highly significant (P , .0001, all readers) preference for gadobenate dimeglumine was demonstrated for all other qualitative end points. Inter-reader agreement was good for all evaluations (K = 0.414 - 0.629). Significantly superior CNR and LBR were determined for gadobenate dimeglumine (P , .019, all readers).. ...
These results indicate that pretreatment of rats with the synthetic catalytic scavenger of ROS, EUK-134, prevents oxidative stress and produces a significant degree of protection against the pathological manifestations of KA-induced seizure activity in hippocampus and piriform cortex. Although numerous studies have suggested that ROS are critically involved in excitotoxicity (see refs. 5, 30, and 31 for reviews), very few studies have demonstrated convincingly, in an in vivo excitotoxic model, a causal relationship between increased production of ROS and neuronal damage (7, 32). A clear demonstration of the crucial role of ROS in excitotoxicity should include: (i) evidence for increased production of ROS specifically in neuronal populations at risk with excitotoxicity before overt signs of neuronal damage and (ii) evidence that manipulations aimed at preventing ROS accumulation reduce neuronal damage without interfering with excitatory amino acid receptor functions. The former has been difficult ...
Detail záznamu - Synthesis and Electrochemistry of Cyclopentadienyl Ferratricarbollides Substituted by Me and Ph Groups on the Cage Carbon Atoms - Detail záznamu - Knihovna Akademie věd České republiky
In Co(C5H5)2 the Co centre is sandwiched between two cyclopentadienyl (Cp) rings. The Co-C bond lengths are about 2.1 Å, slightly longer than the Fe-C bond in ferrocene.[3]. Co(C5H5)2 belongs to a group of organometallic compounds called metallocenes or sandwich compounds.[4] Cobaltocene has 19 valence electrons, one more than usually found in organotransition metal complexes such as its very stable relative ferrocene. (See 18-electron rule.) This additional electron occupies an orbital that is antibonding with respect to the Co-C bonds. Consequently, the Co-C distances are slightly longer than the Fe-C bonds in ferrocene. Many chemical reactions of Co(C5H5)2 are characterized by its tendency to lose this extra electron, yielding an 18-electron cation known as cobaltocenium: ...
Over the past several years we have devised and expanded the capabilities of Zeeman atomic absorption spectroscopy (ZAA). Using this technique, trace elements in a complex matrix can be directly analyzed with high accuracy even when there is only one atom of interest contained in several million atoms of the host material. Quantities in the nanogram, or in some cases picogram, range can be determined within IS seconds for more than 30 elements. Because of its high selectivity and high sensitivity, ZAA can be used as a new technique for organometallic species determination by interfacing with a high pressure liquid chromatograph (HPLC). The HPLC separates various molecular species. Different kinds of mobil solvents can be directly introduced in the ZAA detection system; even organic solvents or high concentration salt solutions. Then, organometallic species in the ppb range are separately detected according to their retention times. This technique has a much larger field of application than HPLC coupled
The latter for most compounds. By fluxional I mean that some compounds interconvert between different shapes. Examples of these are the organometallic compounds such as bis(cyclopentadienyl)mercury (II) that exists both as the bis-monohapto and bis-pentahapto complexes. In the bis-monohapto complex the mercury is sigma bonded once to two carbon atoms... one on each of the two cyclopentadiene groups. In the bis-pentahapto complex, the mercury is bonded to every carbon in both cyclopentadienyl groups. Thats about as fluxional as you can get ...
The complexes CpMo(CO)3X (X = Cl, Br, I; Cp = C5H4CH3) and [CpMo(CO)3(L)]+ (L = CH3CN, CH3COCH3) were synthesized and their electrochemistry and electron transfer induced substitution reactions were studied. Electrochemical ...
The principal idea of this volume is to offer a Capita Selecta of unconventional and thought-provoking topics in organometallic chemistry, presented by experts in each field. As intended, this approach leads either to reviews covering a specific uncommon class of organometallic compounds or to overviews which relate uncommon physical properties with various classes of organometallic compounds. The contributions are streamlined thus onto two main axes - unusual properties reflecting structures and bonding situations, on the one hand, and uncommon structural features or structure-reactivity relationships, on the other. Extensive cross-referencing of useful information is provided, making this volume accessible for people working in rather different areas of organometallic chemistry ...
This publication or database and the information in it is protected by copyright. All reproductions of this copyrighted material must be for non-commercial educational fair use as defined by 17 U.S.C. 107.. ...
Development of organic methodologies.. Total synthesis of biological active products.. Organometallic complexes: design, synthesis and catalytic applications.. Greener chemistry.. Cancer research.. Synthesis and applications of porous materials such as MOFs and ZIFs.. Currently Funded Research Projects:. Project 1: Development of Adsorption-Based CO2 Separation System Using MOF Materials, Type: King Abdulaziz City for Science and Technology-Technology Innovation Center (KACST-TIC), Durations: Nov/13-Oct/15, Amount: SR 1,982,000. Role: Co-I. Project 2: N-Heterocyclic Carbene Complexes: Design, Synthesis and Catalytic Applications, Type: King Abdulaziz City for Science and Technology (KACST), Durations: Aug/13-Jul/15, Amount: SR 861,950. Role: P-I. Project 3: Dynamic Kinetic Resolution of Racemic Alcohols by Dual Enzymatic Method, Type: National Science, Technology and Innovation Plan (NSTIP), Duration: Mar/12-Feb/14, Amount: SR 1,996,800. Role: Co-I. Completed Funded Research ...