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  • iron atoms
  • For example, the iron cluster Fe2(CO)9 contains six 'terminal' carbonyls, bound to only one iron each, and three 'bridging' carbonyls, each of which is bound to both iron atoms. (csbsju.edu)
  • In this way, it is possible for the individual catalytic centres made of iron atoms to be separated from each other by aluminium atoms. (fz-juelich.de)
  • molecule
  • Infrared spectroscopy is often used to assess bond order between specific atoms within a molecule. (csbsju.edu)
  • What will happen to the CO stretching frequency in carbon monoxide if the molecule binds to a palladium atom? (csbsju.edu)
  • The structure helped explain puzzles about ferrocene's conformers, the molecule features an iron atom sandwiched between two parallel cyclopentadienyl rings. (wikipedia.org)
  • The boron atom in this molecule is a key substructure because through it certain proteasomes are blocked that would otherwise degrade proteins. (wikipedia.org)
  • The F2 molecule is commonly described as having exactly one bond (in other words, a bond order of 1) provided by one p electron per atom, as are other halogen X2 molecules. (wikipedia.org)
  • nitrogen
  • More than half the supply of palladium and its congener platinum is used in catalytic converters, which convert as much as 90% of the harmful gases in automobile exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into less noxious substances (nitrogen, carbon dioxide and water vapor). (wikipedia.org)
  • Tetrahedral
  • BARF has a tetrahedral geometry around the central boron atom but each of the four surrounding aryl groups is aromatic and planar. (wikipedia.org)
  • hydrogenation
  • The cluster size of an ensemble of palladium nanoclusters was found to increase on hydrogenation. (esrf.eu)
  • The structural and electronic changes of bulk palladium upon hydrogenation are well documented . (esrf.eu)
  • As hydrogen in a metal can decrease the strength of the host metal bonding, this raises the question of how an ensemble of palladium nanoclusters will interact during and after hydrogenation. (esrf.eu)
  • molecular
  • Molecular self-assembly has often been suggested as the ultimate route for the bottom-up construction of building blocks atom-by-atom for functional nanotechnology, yet structural design or prediction of nanomolecular assemblies is still far from reach. (pnas.org)
  • A. E. Baber , H. L. Tierney, T. J. Lawton, E. C. H. Sykes, An Atomic-scale View of Palladium Alloys and their Ability to Dissociate Molecular Hydrogen, ChemCatChem , 2011 , 3 , 607-614. (bnl.gov)
  • But palladium has one significant feature-the capability to absorb (dissolve into itself) molecular hydrogen. (wikipedia.org)
  • The high frequency of molecular vibration is a consequence of the small mass of the hydrogen atom as compared to the mass of the oxygen atom and this makes detection of hydroxyl groups by infrared spectroscopy relatively easy. (wikipedia.org)
  • While an individual fluorine atom has one unpaired electron, molecular fluorine (F2) has all the electrons paired. (wikipedia.org)
  • nanowires
  • Herein, we prepared a 3D interwoven structure with Pd atoms deposited on homogeneously bound MnO 2 nanowires and carbon nanotubes (CNTs) (Pd/MnO 2 -CNT), allowing the combination of superior catalytic performance of atomic Pd incorporated in the metal oxide and the high conductivity of CNT. (rsc.org)
  • unusual
  • This transition metal dichalcogenide has an unusual monoclinic structure, with pairs of selenium atoms existing as dimers forming layers between palladium atom sheets. (wikipedia.org)
  • The aurophilic interaction is thought to result from electron correlation of the closed-shell components, which is unusual because closed-shell atoms generally have negligible interaction with one another at distances on the scale of the Au-Au bond. (wikipedia.org)
  • Defects
  • clarification needed] Palladium films with defects produced by alpha particle bombardment at low temperature exhibit superconductivity having Tc=3.2 K. Naturally occurring palladium is composed of seven isotopes, six of which are stable. (wikipedia.org)
  • crystalline
  • 2D Materials, sometimes referred to as single layer materials, are crystalline materials consisting of a single layer of atoms. (wikipedia.org)
  • single
  • Our strategy can be generalized to design new single atom electrocatalysts for numerous functionalities. (rsc.org)
  • It is well known that palladium only delivers the desired product when active centres that are as small as possible are present, approximately in the shape of single palladium atoms in an otherwise inactive matrix. (fz-juelich.de)
  • cluster
  • We investigated the effect of hydrogen exposure on a palladium cluster assembled film produced with a dual-target dual-laser vaporisation source with three different techniques: X-ray diffraction (XRD), Extended X-ray absorption fine structure (EXAFS) and scanning tunnelling microscopy (STM). (esrf.eu)
  • phases
  • E = E 0 + R T F ln ⁡ a H + ( p H 2 p 0 ) 1 / 2 {\displaystyle E=E^{0}+{RT \over F}\ln {a_{\mathrm {H} ^{+}} \over ({\frac {p_{\mathrm {H} 2}}{p^{0}}})^{1/2}}} When palladium is electrochemically charged by hydrogen, the existence of two phases is manifested by a constant potential of approximately +50 mV compared to the reversible hydrogen electrode. (wikipedia.org)
  • coordination
  • The average grain size was derived both from the width of the XRD Bragg peaks and the coordination number around Pd atoms obtained from EXAFS, whereas the (lateral) diameter of the nanoclusters at the sample surface was measured directly by STM. (esrf.eu)
  • steric
  • However, hyperconjugation has been suggested as an explanation for the preference of the staggered conformation of ethane because the steric hindrance of the small hydrogen atom is far too small. (wikipedia.org)
  • pathway
  • Furthermore he thought that fumarate was part of a reductive pathway where hydrogen atoms were taken up from the food and passed from oxaloacetate to malate to fumarate to succinate and then to a cytochrome complex where they were eventually combined with water. (blogspot.de)
  • electron
  • High-energy hydrogen (deuterium) atoms are obtained during the excitation of the hydrogen subsystem by electron irradiation due to the generation of plasma oscillations (plasmons) in a crystal lattice or hydrogen subsystem [ 9 , 10 ]. (mdpi.com)
  • Induction is the redistribution of electron density through a traditional sigma bonded structure according to the electronegativity of the atoms involved. (wikipedia.org)
  • Conjugation is not only affected by electronegativity of the connected atoms but also affected by the position of electron lone pairs with respect to the pi-system. (wikipedia.org)
  • If atoms are brought too close together, there is an associated cost in energy due to overlapping electron clouds (Pauli or Exchange interaction, or Born repulsion), and this may affect the molecule's preferred shape (conformation) and reactivity. (wikipedia.org)
  • substitution
  • The modification of isoCA-4 by introduction of difluoromethoxy group at the para-position (3i) and substitution of the two protons of the linker by two fluorine atoms (3m), produced the most active compounds in the series, with IC50 values of 0.15-2.2 nM (3i) and 0.1-2 nM (3m) respectively, against a panel of six cancer cell lines. (deepdyve.com)
  • The symmetrical substitution pattern with reactive bromine atoms makes 1,2,4,5-tetrabromobenzene an interesting starting compound for nematic liquid crystals with crossed mesogens and for columnar (diskotic) liquid crystals with an extensive planar, "board-like" tetrabenzoanthracene ring system. (wikipedia.org)
  • In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. (wikipedia.org)
  • Heck
  • Chiral palladium complexes can be used to synthesize chiral intramolecular Heck reaction products in non-racemic form. (wikipedia.org)
  • The Heck reaction is the palladium-catalyzed coupling of an aryl or alkenyl halide with an alkene to form a substituted alkene. (wikipedia.org)
  • Ring sizes produced by the intramolecular Heck reaction range from four to twenty-seven atoms. (wikipedia.org)
  • capsules
  • These palladium-equipped capsules can be used to promote the uncaging of propargyl-protected phenols, as well as Suzuki-Miyaura cross-couplings, in water, and under physiologically compatible temperatures. (metbiocat.eu)
  • The X-rays and gamma rays are of low enough energy to deliver a higher radiation dose selectively to nearby tissues, in "permanent" brachytherapy where the isotope capsules are left in place (I-125 competes with palladium-103 in such uses). (wikipedia.org)
  • Thus
  • In some cases, for an atom to interact with sterically shielded atoms, it would have to approach from a vicinity where there is less shielding, thus controlling where and from what direction a molecular interaction can take place. (wikipedia.org)
  • process
  • In this Account , we present recent efforts on the development of platinum- and gold-catalyzed formal cycloadditions of allenes, only including annulations initiated by a direct metal-promoted activation of the allene moiety.This Account is organized considering the number of atoms engaged in the annulation process, and when possible, we present the results in a chronological order. (metbiocat.eu)
  • Oxidative addition of an aryl perfluorosulfonate generates a cationic palladium aryl complex V. The mechanism then proceeds as in the neutral case, with the difference that an extra site of coordinative unsaturation exists on palladium throughout the process. (wikipedia.org)
  • Later, scientists realized that the metal atom gains electrons in this process. (wikipedia.org)
  • group
  • For example, an allyl group can coordinate to palladium in the η¹ mode (only one atom of an allyl group attached to palladium) or the η³ mode (3 atoms attached to palladium). (wikipedia.org)
  • The IUPAC Gold Book provides a more general definition of a class (a) metal ion, as "A metal ion that combines preferentially with ligands containing ligating atoms that are the lightest of their Periodic Group", and a class (b) metal as one that combines preferentially with ligands containing ligating atoms other than the lightest of their Periodic Group. (wikipedia.org)
  • elements
  • Ancient Greek philosophers debated the existence of a vacuum, or void, in the context of atomism, which posited void and atom as the fundamental explanatory elements of physics. (wikipedia.org)
  • include
  • Further examples include packing efficiency (the fraction of volume in a crystal structure occupied by atoms) and the Goldhammer-Herzfeld criterion ratio. (wikipedia.org)
  • Other methods for the direct formation of aromatic rings from substituted, unsaturated precursors include the Dötz reaction, palladium-catalyzed [4+benzannulation of enynes with alkynes, and Lewis-acid-mediated [4+cycloaddition of enynes with alkynes. (wikipedia.org)