Four series of hydrogen bonded complexes of formamide and substituted benzoic acids and benzoates were studied in the light of substituent effect on intermolecular interactions. The analysis based on energy of interaction, geometry, QTAIM-derived properties of hydrogen bond critical point and energy of hydrogen bonds were made and discussed. The opposite effect of the substituent on hydrogen bo...

Hydrogen isotope ratios (2H/H or D/H) of long-chain unsaturated ketones (alkenones) preserved in lake and marine sediments hold great promise for paleoclimate studies. However, compound-specific hydrogen isotope analysis of individual alkenones has not been possible due to chromatographic coelution of alkenones with the same carbon chain length but different numbers of double bonds. Published s...

The title compound, C(8)H(8)N(2)O(4), is almost planar (r.m.s. deviation = 0.037 Å) and an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(8) loops. Inter-molecular N-H⋯O hydrogen bonds (involving the same H atom that forms the intra-molecular hydrogen bond) link the dimers into infinite sheet...

Hydrogen bonding interactions between biological chromophores and their surrounding protein and solvent environment significantly affect the photochemical pathways of the chromophore and its biological function. A common first step in the dynamics of these systems is excited state proton transfer between the noncovalently bound molecules, which stabilizes the system against dissociation and pri...

The methyl-amino-propyl chain in the title compound, C(13)H(21)NO, adopts an extended zigzag conformation and the N atom shows a trigonal coordination. The N atom acts as hydrogen-bond acceptor to the hy-droxy group of an adjacent mol-ecule, generating a helical chain running along the b axis. The amino H atom is not involved in hydrogen bonding.

The title compound, C16H16N4O7, is close to being planar, with a dihedral angle of 3.15 (11)° between the benzene rings. The meth-oxy groups at the ortho- and para-positions of the 2,4,5-tri-meth-oxy-phenyl group are almost coplanar with the ring [deviations of the C atoms = 0.017 (2) and -0.025 (2) Å, respectively], whereas the meta-meth-oxy group deviates slightly [C-atom displacement = 0.162...

The interactions between hydrogen and silicon are investigated based on first-principles calculations. After a comprehensive overview of various configurations attention is focused on the energetics and dissociation of Si–H bonds. An examination of the dissociation mechanism of Si–H bonds suggests an explanation for the observed difference in stability between hydrogen and deuterium at dangling...

We report a density functional theory (DFT) study of microscopic detailed effects of the bonding configuration of nitrogen-doped graphene (N-graphene) within the carbon lattice (including pyridinic, pyrrolic, and graphitic N) on the reactivity and mechanistic processes of H2O2 reduction reaction. We simulated the adsorption process of H2O2, analyzed the mechanistic processes, and calculated the...

Theoretical studies of hydrogen bond network rearrangement (HBNR) dynamics in liquid water have indicated that librational motions initiate the hydrogen bond breaking/formation processes. We present the results of using a simple time evolution method to extract and compare the tunneling lifetimes for motions that break and reform the hydrogen bond for the water dimer, trimer, and pentamer from ...

the relative stability of hydrogen-bonded of molybdate-phosphonic acid (mpa) complex (1:2) ingas phase has been carried out using density functional theory (dft) methods. the methods are usedfor calculations are b3lyp, bp86 and b3pw91 that have been studied in two series of basis sets: d95**and 6-31+g(d,p) for hydrogen and oxygen atoms; lanl2dz for mo and phosphorus. predictedhydrogen-bond geom...