Water bridges anchored by a C–H⋯O hydrogen bond: the role of weak interactions in molecular solvation

2016 ◽  
Vol 18 (40) ◽  
pp. 27745-27749 ◽  
Author(s):  
Aditi Bhattacherjee ◽  
Sanjay Wategaonkar
Keyword(s):  
Hydrogen Bond ◽  
Ab Initio ◽  
Infrared Spectra ◽  
Direct Evidence ◽  
Weak Interactions ◽  
Imidazole Ring ◽  
Water Bridges ◽  
Hydrogen Bonded

Hydrogen-bonded water bridges are re-directed from a polar NH bond to a weakly activated C(2)–H bond upon N-methylation. Infrared spectra, supported by ab initio calculations, provide direct evidence of the role of the C(2)–H donor in the solvation of the imidazole ring.

scholarly journals A test of ab initio-generated, radial intermolecular potential energy functions for five axially-symmetric, hydrogen-bonded complexes B⋯HF, where B = N2, CO, PH3, HCN and NH3

2021 ◽  
Vol 23 (12) ◽  
pp. 7271-7279
Author(s):  
Anthony C. Legon
Keyword(s):  
Hydrogen Bond ◽  
Potential Energy ◽  
Ab Initio ◽  
Intermolecular Potential ◽  
Axially Symmetric ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Acceptor Atom ◽  
Bonded Complexes ◽  
Hydrogen Bonded

Radial P.E. functions of hydrogen-bonded complexes B⋯HF (B = N2, CO, PH3, HCN and NH3) have been calculated ab initio at the CCSD(T)(F12C)/cc-pVTZ-F12 level as a function of the hydrogen-bond length r(Z⋯H), where Z is the H-bond acceptor atom of B.

The infrared spectra of theobromine salts

1967 ◽  
Vol 45 (23) ◽  
pp. 2899-2902 ◽  
Author(s):  
Denys Cook ◽  
Zephyr R. Regnier
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Imidazole Ring ◽  
Free Base ◽  
Absorption Bands ◽  
Out Of Plane ◽  
Stretching Vibrations ◽  
Deformation Modes ◽  
Infrared Absorption Bands

From the infrared spectra of theobromine salts it is concluded that the salts are probably arranged in hydrogen-bonded centrosymmetric pairs involving [Formula: see text] interactions. [Formula: see text] anion− hydrogen bonds are formed by protonation of the free nitrogen atom (N9) in the imidazole ring. Infrared absorption bands arising from the former hydrogen bond constantly appear near 3 000 cm−1, whereas those from the latter shift from 2 580 to 3 300 cm−1, depending on the anion. In-plane NH and N+H deformation modes give bands near 1 485 and 1 160 cm−1, respectively. Out-of-plane NH modes have been located, but precise assignments are not possible.The assignments for some other bands which show deuteration shifts are detailed, and the carbonyl stretching vibrations which increase in frequency on protonation of the free base are identified.

Structures of F - -(CH4)n and Cl - -(CH4)n (n = 1,2) Anion Clusters Elucidated through Ab Initio Calculations and Infrared Spectra

2004 ◽  
Vol 57 (12) ◽  
pp. 1157 ◽  
Author(s):  
Zoë M. Loh ◽  
Rosemary L. Wilson ◽  
Duncan A. Wild ◽  
Evan J. Bieske ◽  
Mark S. Gordon
Keyword(s):  
Hydrogen Bond ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Infrared Spectra ◽  
Halide Anion ◽  
Fermi Interaction ◽  
Anion Clusters ◽  
Infrared Intensity

Ab initio calculations are performed at the MP2/aug-cc-pVTZ level for F−-CH4 and Cl−-CH4, to show that the dimers have C3v symmetry with the CH4 sub-unit attached to the halide anion by a single hydrogen bond. This geometry is consistent with infrared spectra of F−-CH4 and Cl−-CH4 recorded in the CH-stretch region. The calculations also indicate substantial anharmonicity in the H-bonded CH stretch of F−-CH4. Infrared spectra of the F−-(CH4)2 and Cl−-(CH4)2 trimer clusters are consistent with structures that have two equivalent CH4 sub-units H-bonded to the halide core. Additional bands in the F−-(CH4)2 spectrum are assigned as transitions to CH4 bending overtone and combination levels, gaining infrared intensity from Fermi interaction with the H-bonded CH stretch.

Infrared Spectra of Hydrogen-Bonded Ionic Crystals:  Ab Initio Study of Mg(OH)2and β-Be(OH)2

2004 ◽  
Vol 108 (36) ◽  
pp. 13632-13637 ◽  
Author(s):  
Piero Ugliengo ◽  
Fabien Pascale ◽  
Mohammadou Mérawa ◽  
Pierre Labéguerie ◽  
Sergio Tosoni ◽  
...  
Keyword(s):  
Ab Initio ◽  
Infrared Spectra ◽  
Ionic Crystals ◽  
Ab Initio Study ◽  
Hydrogen Bonded
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