The main interaction between pyridine and zeolites leads to form a hydrogen bond between the N atom of pyridine and OH groups of zeolites. The present work reports a theoretical study about the structural, vibrational and topological properties of the charge distribution of the molecular complexes between pyridine and a series of acids sites of zeolites. The calculated structural parameters...

In the title compound, C(11)H(14)N(2)O(5)S, the amide O atom acts as a hydrogen-bond acceptor from a carboxyl-ate O atom and a secondary amino N atom. In addition, one of the sulfonyl O atoms and the carbonyl O atom of the carboxyl group also form hydrogen bonds with the primary amido N atom. These intermolecular hydrogen-bonding inter-actions give rise to a layer structure, with the layers par...

In the title compound, C(10)H(12)N(2)O(5)S, one of the sulfonyl O atoms is hydrogen bonded to the amido N atom of an adjacent mol-ecule. There is also a weak hydrogen-bonding inter-action between the other sulfonyl O atom and the secondary amino N atom. In addition, the amido O atom is also hydrogen bonded to a carboxyl O atom. These hydrogen-bonding inter-actions give rise to a layer structure...

The stereochemistry of the hydrogen elimination that occurs during the formation of the Delta(4)- and Delta(2)'-double bonds of abscisic acid has been determined from the (14)C/(3)H ratios in abscisic acid biosynthesized by avocado fruit from [2-(14)C,(2R)-2-(3)H(1)]-, [2-(14)C,(2S)-2-(3)H(1)]- and [2-(14)C,(5S)-5-(3)H(1)]-mevalonate. Setting the (14)C/(3)H ratio at 3:3 for [2-(14)C,(2R)-2-(3)H...

The asymmetric synthesis of enantiopure pyrrolidines is reported via a streamlined strategy relying on two sequential C?H functionalizations simple hydrocarbons. first step regio- and stereoselective catalytic nitrene insertion. Then, subsequent diastereoselective cyclization involving 1,5-hydrogen atom transfer (HAT) from N-centered radical leads to the formation that can then be converted the...

In the title proton-transfer organic salt, C5H6.3N5 (+)·C8H4.7O4 (-)·C3H7NO, the adeninium moiety is protonated at the N atom in the 1-position of the 6-amino-7H-purin-1-ium (adeninium) cation. In the solid state, the second acidic proton of isophthalic acid is partially transferred to the imidazole N atom of the adeninium cation [refined O-H versus N-H ratio = 0.70 (11):0.30 (11)]. Through the...

Bare vanadium oxide and hydroxide cluster cations, V(m)O(n)+ and V(m)O(n-1) (OH)+ (m = 1-4, n = 1-10), generated by electrospray ionization, were investigated with respect to their reactivity toward methanol using mass spectrometric techniques. Several reaction channels were observed, such as abstraction of a hydrogen atom, a methyl radical, or a hydroxymethyl radical, elimination of methane, a...

The impact parameter Faddeev approach to atomic three-body collisions which has been developed for, and successfully applied to, ion-atom scattering processes, has now been developed further by including, instead of the Coulomb potentials, the full two-particle oo-shell Coulomb T-matrices in alìtriangle' contributions to the eeective potentials. Results of calculations of proton-hydrogen collis...

We have completed a new study of the formation of hydrogen lines in dense magnetized plasmas. We have developed a global formalism including the effects of the magnetic field and of the motional electric field. The latter, resulting from the motion of the radiating hydrogen atom in the magnetic field, modifies the structure of the matrices appearing in the equation of transfer of the Stokes vec...