The nature of the intramolecular hydrogen bond in the enol tautomer of 2,4-pentanedione has been investigated by high resolution proton and deuteron magnetic resonance spectroscopy. An unusually large deuterium isotope effect on the chemical shift of the bridge hydrogen has been observed. This unexpected result, together with the observation of a pronounced temperature dependence for both the p...

3,4-diaminobenzamidinium was synthesized and spectroscopically and structurally characterized, both at room temperature and at 150 K. The crystal structure consists of two 3,4diaminobenzamidinium cations and two chloride anions. The planar amidinium group is inclined by 35.35(5)° and 28.96(7)° in respect to the diaminobenzene moiety in the two crystallographically independent cations. The ions ...

-The introduction of artificial +b/3 stacking faults into well-crystallized kaolinite by intercalating and removing hydrazine had no observable effect on the solid-state 29Si nuclear magnetic resonance spectrum of kaolinite. Also, the introduction of such stacking faults did not alter the hydroxyl-stretching region of the infrared spectrum, implying no change in the hydrogen bonding between the...

The spontaneous and collision-assisted hydrogen-atom abstracting reaction (HA) dynamics of triplet benzil are investigated through the combination of transient absorption spectroscopy with TD-DFT calculations. HA dynamics exhibit a remarkable dependence on the hydrogen donor properties. The effects of the triplet-state hydrogen bonding on the reaction dynamics are illustrated. In particular, it...

Intramolecular hydrogen bonding (HB) is one of the most studied noncovalent interactions of molecules. Many physical, spectral, and topological properties of compounds are under the influence of HB, and there are many parameters used to notice and to describe these changes. Hitherto, no general method of measurement of the energy of intramolecular hydrogen bond (EHB) has been put into effect. W...

Electron spin resonance (ESR) and dc-magnetization experiments have been performed in Gd-doped amorphous (a-)silicon lms. The lms were deposited by the cosputtering technique following di erent conditions rendering samples with varying Gd and hydrogen concentrations. In addition to lms with di erent contents of impurities and, in order to probe the in uence of the atomic structure on the magnet...

In the title compound, C(14)H(12)ClN(3)OS, the short exocyclic N-C bond lengths indicate resonance in the thiourea part of the mol-ecule. The title compound is stabilized by an intra-molecular N-H⋯N hydrogen bond, which results in the formation of a six-membered ring. In addition, it shows a synperiplanar conformation between the thio-carbonyl group and the pyridine group. Inter-molecular N-H⋯S...

The atomistic mechanism of rapid hydrogen production from water by an aluminum cluster is investigated by ab initio molecular dynamics simulations on a parallel computer. A low activation-barrier mechanism of hydrogen production is found, in which a pair of Lewis acid and base sites on the cluster surface plays a crucial role. Hydrogen production is assisted by rapid proton transport in water v...