Vibrational dynamics and relaxation of excited non-hydrogen bonded OH-aluminols from non-equilibrium AIMD, towards in silico time-resolved VSF experiments.

In the triple helical structure of collagen proposed by RAMACHANDRAN and co-workers1, 2 (see ref. 2 for earlier references), there are two N H . . . 0 hydrogen bonds for every three residues in each chain. In the modification of the RAMACHANDRANKARTHA structure proposed by RICI~ A N D C R I C K a, the three chains are pushed slightly farther apart from their positions in this two-bonded structu...

The total interaction energies of altogether 15 hydrogen-bonded nucleic acid base pairs containing unusual base tautomers were calculated. The geometry properties of all selected adenine-thymine and guanine-cytosine hydrogen-bonded base pairs enable their incorporation into DNA. Unusual base pairing patterns were compared with Watson-Crick H-bonded structures of the adenine-thymine and guanine-...

The influence of small monovalent metal ions on hydrogen bonds of aquo-protein complexes is studied on Li/HCONH2-OH2 as an example. Using results obtained from ab initio calculations with minimal GLO basis sets, the remarkable changes in the hydrogen bond energy and charge distribution, due to metal ion complex formation, are discussed. The metal ion seems to enhance strongly the donor-acceptor...

Hydrogen bond interactions between acetone and supercritical water are investigated using a combined and sequential Monte Carlo/quantum mechanics (S-MC/QM) approach. Simulation results show a dominant presence of configurations with one hydrogen bond for different supercritical states, indicating that this specific interaction plays an important role on the solvation properties of acetone in su...

The basic retention mechanisms of reversed-phase and hydrophilic-interaction liquid chromatography (HILIC) were quantitatively analyzed using simple molecular mechanics (MM) calculations. The model bonded phases were composed of an alkyl chain bonded to siloxane-like molecules. The head of the alkyl chain was a hydroxyl group, used to study retention mechanisms of HILIC. The standard analytes w...

The structures of 2-acetamido-4-tolyl-1,3-thiazole, C(12)H(12)N(2)OS, (I), and 2-amino-4-tolyl-1,3-thiazolium chloride dihydrate, C(10)H(11)N(2)S(+).Cl(-).2H(2)O, (II), reveal that both molecules are essentially planar, with the respective dihedral angles between the benzene and thiazole rings being 2.9 (1) and 10.39 (7) degrees . Compound (I) associates via a single N-H...O interaction to form...