The hairpin ribozyme, a small catalytic RNA consisting of two helix-loop-helix motifs, serves as a paradigm for RNA folding. In the active conformer, the ribozyme is docked into a compact structure via loop-loop interactions. The crystal structure of the docked hairpin ribozyme shows an intricate network of hydrogen bonding interactions at the docking interface, mediated by the base, sugar, and...

In the title compound C(11)H(9)NO(2), the phenyl and isoxazole rings are almost coplanar, making a dihedral angle of 1.14 (9)°. This planarity is also assisted by an intra-molecular C-H⋯O hydrogen bond between the phenyl ring and the carbonyl O atom. In the crystal, weak C-H⋯O inter-actions generate a layered structure parallel to the ac plane.

Hydrogen production by metal particles in water could provide a renewable energy cycle, if its reaction kinetics is accelerated. Here, ab initio molecular dynamics simulation reveals rapid hydrogen production from water by a cluster (or superatom) consisting of a magic number of aluminum atoms, Al{n} (for instance, n=12 or 17). We find a low activation-barrier mechanism, in which a pair of Lewi...

The title compound, C14H18N4O, synthesized from an unconventional microwave-assisted method using caesium carbonate as catalyst, has an approximately planar conformation with the pyridyl and pyrazole rings inclined by a dihedral angle of 7.94 (3)°, allowing the formation of an intra-molecular N-H⋯N hydrogen bond. The supra-molecular assembly has a three-dimensional arrangement controlled mainly...

We have performed a detailed structural and optical investigation of hydrogenated nanocrystalline silicon (nc-Si:H) thin films prepared by plasma-enhanced chemical vapor deposition. The microstructural properties of these thin films are characterized and interpreted physically based on the growth mechanism. Infrared spectroscopy reveals that the bonded hydrogen in a platelet-like configuration,...

Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/A1203, was carried out in thirteenvarious solvents (four alcoholic solvents, six aprotic polar solvents and three non polar solvents) at 25 °C.Single-parameter correlations of logk vs. normalized polarity parameter (ETN), hydrogen-bond acceptorbasicity (p), hydrogen-bond donor acidity (a) and dipolarity/polarizibility (it*) d...

heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by pt/a1203, was carried out in thirteenvarious solvents (four alcoholic solvents, six aprotic polar solvents and three non polar solvents) at 25 °c.single-parameter correlations of logk vs. normalized polarity parameter (etn), hydrogen-bond acceptorbasicity (p), hydrogen-bond donor acidity (a) and dipolarity/polarizibility (it*) d...