Hydrogen bond
Certain hydrogen bonds - improper hydrogen bonds - show a blue shift of the X−H stretching frequency and a decrease in the bond ... The ideal bond angle depends on the nature of the hydrogen bond donor. The following hydrogen bond angles between a ... Hydrogen bonds are represented as H···Y system, where the dots represent the hydrogen bond. Liquids that display hydrogen ... This type of bond is much stronger than a "normal" hydrogen bond. The effective bond order is 0.5, so its strength is ...
Hydrogen-bond catalysis
Hydrogen-bond catalysis is a type of organocatalysis that relies on use of hydrogen bonding interactions to accelerate and ... Link Asymmetric Hydrogen Bond Catalysis. MacMillan Group Meeting Presentation by Anthony Mastracchio. Link Hydrogen Bonding in ... Organocatalysis Thiourea organocatalysis Hydrogen bond Hydrogen Bond Catalysis. Evans Group Meeting Presentation by Peter H. ... It is often difficult to distinguish between hydrogen-bond catalysis and general acid catalysis. Hydrogen-bond donors can have ...
Carbon-hydrogen bond
In chemistry, the carbon-hydrogen bond (C−H bond) is a chemical bond between carbon and hydrogen atoms that can be found in ... Carbon-hydrogen bonds have a bond length of about 1.09 Å (1.09 × 10−10 m) and a bond energy of about 413 kJ/mol (see table ... The length of the carbon-hydrogen bond varies slightly with the hybridisation of the carbon atom. A bond between a hydrogen ... Carbon-carbon bond Carbon-nitrogen bond Carbon-oxygen bond Carbon-fluorine bond March, Jerry (1985), Advanced Organic Chemistry ...
Symmetric hydrogen bond
This type of bond is much stronger than "normal" hydrogen bonds, in fact, its strength is comparable to a covalent bond. It is ... A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two ... Because of this problem, some consider it to be an ionic bond. Steiner, Thomas (2002). "The Hydrogen Bond in the Solid State". ... It is also seen in the bifluoride ion [F−H−F]−. Much has been done to explain the symmetric hydrogen bond quantum-mechanically ...
Hydrogen-bonded organic framework
... s (HOFs) are a class of two- or three-dimensional materials formed by hydrogen bonds among ... Hydrogen bonds formed among various monomers guarantee the construction of hydrogen-bonded organic frameworks with different ... based hydrogen-bonded network with interpenetrated diamond topology. Meanwhile diverse works of guest-induced hydrogen-bonded ... therefore different hydrogen bonding pairs should be selected following systematic requirements. The hydrogen bonding pairs ...
Low-barrier hydrogen bond
... strong hydrogen bonds. Standard hydrogen bonds are longer (e.g. 2.8 Å for an O···O h-bond), and the hydrogen ion clearly ... the bond is characterized as a single-well or short-strong hydrogen bond. Low barrier hydrogen bonds occur in the water- ... A Low-barrier hydrogen bond (LBHB) is a special type of hydrogen bond. LBHBs can occur when the pKa of the two heteroatoms are ... Low-barrier hydrogen bonds have been proposed to be relevant to enzyme catalysis in two types of circumstance. Firstly, a low- ...
Carbon-hydrogen bond activation
... carbon-hydrogen bond functionalization (C−H functionalization) is a type of organic reaction in which a carbon-hydrogen bond is ... in which a low-valent metal center inserts into a carbon-hydrogen bond, which cleaves the bond and oxidizes the metal. LnM + RH ... Hoyano, James K.; Graham, William A. G. (1982). "Oxidative addition of the carbon-hydrogen bonds of neopentane and cyclohexane ... Transforming C-H bonds into C-B bonds through borylation has been thoroughly investigated due to their utility in synthesis (i. ...
Tetraethylammonium chloride
K. M. Harmon, J. M. Gabriele and J. Harmon (1990). "Hydrogen bonding Part 30. New IR spectra-structure correlations for ... Harmon, Kenneth M.; Gabriele, Julie M. (1981). "Hydrogen bonding. 11. Infrared study of the water-chloride ion cluster in ...
Self-healing hydrogels
Hydrogen bonding is a strong intermolecular force that forms a special type of dipole-dipole attraction. Hydrogen bonds form ... Hydrogen bonds are stronger than normal dipole-dipole interactions and dispersion forces but they remain weaker than covalent ... As the chain increases in length, the reach of the carboxyl group becomes more flexible and the hydrogen bonds can mediated. ... The polar groups in the polymer strongly bind water molecules and form hydrogen bonds which also cause hydrophobic effects to ...
Oxygen compounds
1 per hydrogen atom) to an adjacent oxygen atom in a separate molecule. These hydrogen bonds between water molecules hold them ... "Water Hydrogen Bonding". Retrieved 2008-01-06. Also, since oxygen has a higher electronegativity than hydrogen, the charge ... Hydrogen atoms are covalently bonded to oxygen in a water molecule but also have an additional attraction (about 23.3 kJ·mol− ... Hydrogen peroxide (H 2O 2) can be produced by passing a volume of 96% to 98% hydrogen and 2 to 4% oxygen through an electric ...
Transmembrane protein
... type hydrogen bonding". Biochemistry. 28 (24): 9379-9385. doi:10.1021/bi00450a019. PMID 2482072. Kubyshkin, Vladimir; Grage, ... the complete unfolding would require breaking down too many α-helical H-bonds in the nonpolar media). On the other hand, these ... formation of non-native disulfide bonds, or unfolding of peripheral regions and nonregular loops that are locally less stable.[ ... α-helical transmembrane proteins from the outer bacterial membrane Methane monooxygenase Rhomboid protease Disulfide bond ...
Oxygen
... is an oxide of hydrogen and the most familiar oxygen compound. Hydrogen atoms are covalently bonded to oxygen in a water ... These hydrogen bonds between water molecules hold them approximately 15% closer than what would be expected in a simple liquid ... The bond can be variously described based on level of theory, but is reasonably and simply described as a covalent double bond ... Chaplin, Martin (January 4, 2008). "Water Hydrogen Bonding". Archived from the original on October 10, 2007. Retrieved January ...
Bovine submaxillary mucin coatings
In addition, structural rearrangements of proteins as well as hydrogen bonding are suggested to influence the adsorption. The ... Mucins adhere well to polymeric surfaces through various types of bonding: (1) covalent bond attachment (2) electrostatic ... hydrogen bonding; and (4) hydrophobic interactions . These interactions require very close contact between the surface and the ... can be explained by the high amount of protonated amino groups that are present at the pH 4 level that form electrostatic bonds ...
Chemical force microscopy
The strongest hydrogen bonds are at most ~1 eV in energy. This strongly implies that the cantilever has a force constant ... Roughly, intermolecular bond energies can be calculated by: E b o n d = k T B , {\displaystyle E_{bond}=kT_{B},} T B {\ ... Therefore, organic solvents are appropriate for studying van der Waals and hydrogen bonding while electrolytes are best for ... Emsley (1980). "Very strong hydrogen bonding". Chemical Society Reviews. 9: 91. doi:10.1039/cs9800900091. Zlatanova, J.; ...
Thiocarboxylic acid
Chemical compound
Hydrogen bonding occurs when a hydrogen atom bonded to an electronegative atom forms an electrostatic connection with another ... the "Gold Book") (1997). Online corrected version: (2006-) "hydrogen bond". doi:10.1351/goldbook.H02899 "Hydrogen Bonding". www ... "intermolecular bonding - hydrogen bonds". www.chemguide.co.uk. Archived from the original on 2016-12-19. Retrieved 2017-10-28. ... Opposite to covalent bonding, this chemical bond creates two oppositely charged ions. The metals in ionic bonding usually lose ...
Thiosemicarbazide
"Hydrogen bonding in thiosemicarbazide". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 26 ...
Dithiobenzoic acid
M. R. Crampton (1974). "Acidity and hydrogen-bonding". In Saul Patai (ed.). The Chemistry of the Thiol Group. Chichester: John ...
Dihydrogen bond
So-called hydrogen-hydrogen bond interactions have been proposed to occur between two neutral non-bonding hydrogen atoms from ... In chemistry, a dihydrogen bond is a kind of hydrogen bond, an interaction between a metal hydride bond and an OH or NH group ... Because two hydrogen centers are involved, the interaction is termed a dihydrogen bond. Formation of a dihydrogen bond is ... Unconventional Hydrogen Bonds with Element−Hydride Bonds as Proton Acceptor". Acc. Chem. Res. 29 (7): 348-354. doi:10.1021/ ...
Widgiemoolthalite
William H. Green
The Role of Hydrogen Bonding". Journal of the American Chemical Society. 117 (10): 2929-2930. doi:10.1021/ja00115a029. Susnow, ... WO 2019140068, William Green & Ryan Gillis, "Hydrogen sulfide mediated water splitting for hydrogen gas and sulfur dioxide ... "Thiozen: Carbon neutral hydrogen at scale". Thiozen. "La Salle Presents Honorary Degree to Marita Green Lind, M.D." La Salle ... Green is also a co-founder of Thiozen, a start-up company seeking to commercialize a method of converting H2S into hydrogen ...
Force field (chemistry)
Y (X, Y= N, O) hydrogen bond and the calibration of empirical hydrogen-bond potentials". The Journal of Physical Chemistry. 98 ... E bonded = E bond + E angle + E dihedral {\displaystyle E_{\text{bonded}}=E_{\text{bond}}+E_{\text{angle}}+E_{\text{dihedral ... such as angles and bond lengths. Some force fields also include explicit terms for hydrogen bonds. The nonbonded terms are ... 2 bonded atoms, 1, 3 bonded atoms, as well as 1, 4 bonded atoms. Atomic charges can make dominant contributions to the ...
1,3-Dipolar cycloaddition
McGarrity, J.F.; Patai, Saul (1978). "Basicity, acidity and hydrogen bonding". Diazonium and Diazo Groups. Vol. 1. pp. 179-230 ... 5-hydroxy-4-pyrones can also be used to synthesize carbonyl ylides by an intramolecular hydrogen transfer. After hydrogen ... Nakamura, Eiichi; Yoshikai, Naohiko; Yamanaka, Masahiro (2002). "Mechanism of C−H Bond Activation/C−C Bond Formation Reaction ... C-diapolarophiles due to a lower gain in sigma bond energy to offset the loss of a pi bond during the transition state. ...
Ammonium hexafluorotitanate
In the lattice [TiF6]2- octahedra interact with the ammonium cations by hydrogen bonds. Bichowsky, Foord Von (1957). " ... Tun, Z.; Brown, I. D. (1982). "Hydrogen bonding in Diammonium Hexafluorotitanate". Acta Crystallographica Section B Structural ...
Fluorine
Hydrogen and fluorine combine to yield hydrogen fluoride, in which discrete molecules form clusters by hydrogen bonding, ... Fluorination also increases lipophilicity because the bond is more hydrophobic than the carbon-hydrogen bond, and this often ... Hydrogen bonding is another possibility. ZrF 4 melts at 932 °C (1710 °F), HfF 4 sublimes at 968 °C (1774 °F), and UF 4 melts at ... The bond energy of difluorine is much lower than that of either Cl 2 or Br 2 and similar to the easily cleaved peroxide bond; ...
Thiourea organocatalysis
... is the preferred substituent Hydrogen-bonding between thiourea derivatives and carbonyl substrates involve two hydrogen bonds ... especially hydrogen bonding ("partial protonation"). The scope of these small-molecule H-bond donors termed (thio)urea ... Kotke, Mike (2009). Hydrogen-Bonding (Thio)urea Organocatalysts in Organic Synthesis : State of the art and Practical Methods ... Thioureas are often found to be stronger hydrogen-bond donors (i.e., more acidic) than ureas because their amino groups are ...
Molecular dynamics
A hydroxyl group, for example, can be both a hydrogen bond donor, and a hydrogen bond acceptor, and it would be impossible to ... The polar hydrogens are usually retained in the model, because proper treatment of hydrogen bonds requires a reasonably ... Most force fields in chemistry are empirical and consist of a summation of bonded forces associated with chemical bonds, bond ... one typically eliminates all explicit hydrogen atoms except those that have the capability to participate in hydrogen bonds ( ...
CHARMM
Reiher, III WH (1985). Theoretical studies of hydrogen bonding (Thesis). Harvard University. MacKerell AD Jr; et al. (1998). " ... The Urey-Bradley term is a cross-term that accounts for 1,3 nonbonded interactions not accounted for by the bond and angle ... The bond, angle, dihedral, and nonbonded terms are similar to those found in other force fields such as AMBER. The CHARMM force ... bonds}k_{b}(b-b_{0})^{2}+\sum _{angles}k_{\theta }(\theta -\theta _{0})^{2}+\sum _{dihedrals}k_{\phi }[1+cos(n\phi -\delta ...
2-Fluoroethanol
Hydrogen bonding stabilizes the gauche conformer. In a basic solution, 2-fluoroethanol undergoes dehydrofluorination, giving ... Strength of the internal hydrogen bond". The Journal of Physical Chemistry. 95 (4): 1609-1612. doi:10.1021/j100157a020. ...
Homology modeling
2004), hydrogen bonding (Kortemme et al. 2003), and geometric properties (Colovos and Yeates 1993; Kleywegt 2000; Lovell et al ...