Ab initio characterization of (CH3IO3) isomers and the CH3O2 + IO reaction pathways.

The geometries, harmonic vibrational frequencies, relative energetics, and enthalpies of formation of (CH(3)IO(3)) isomers and the reaction CH(3)O(2) + IO have been investigated using quantum mechanical methods. Optimization has been performed at the MP2 level of theory, using all electron and effective core potential, ECP, computational techniques. The relative energetics has been studied by single-point calculations at the CCSD(T) level.

Computational studies of (HIO3) isomers and the HO2 + IO reaction pathways.

The geometries, harmonic vibrational frequencies, relative energetics, and enthalpies of formation of (HIO3) isomers have been examined using quantum mechanical methods. At all levels of theory employed, MP2, B3LYP, and CCSD(T), the lowest energy structure is found to be the HOIO2 form, which shows particular stability. The two isomers HOOOI and HOOIO are closely located at the CCSD(T) level of theory.

Quantum mechanical investigation of the atmospheric reaction CH3O2 + NO.

The important stationary points on the potential energy surface of the reaction CH(3)O(2) + NO have been investigated using ab initio and density functional theory techniques. The optimizations were carried out at the B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) levels of theory while the energetics have been refined using the G2MP2, G3//B3LYP, and CCSD(T) methodologies. The calculations allow the proper characterization of the transition state barriers that determine the fate of the nascent association conformeric minima of methyl peroxynitrite.

Hydrolysis by phospholipase D of phospholipids in solution state or adsorbed on a silica matrix.

Phospholipases D (PLD) catalyse hydrolysis and transphosphatidylation reactions in phospholipids. In the present study, the hydrolytic activity for cabbage PLD was investigated with five different substrates (dipalmitoylphosphatidylethanolamine (DPPE), dipalmitoylphosphatidylcholine (DPPC), didecanoylphosphatidylcholine (DDPC), 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine and lyso-phosphatidylcholine (lyso-PC)) in solution or adsorbed on a silica matrix. In the specific buffer solutions, where the substrates were proved to form large multilamellar polydisperse aggregates, PLD showed preference for DPPC > DPPE > DDPC > 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine > lyso-PC.

Synthesis, structural characterization, and computational studies of novel diiodine adducts with the heterocyclic thioamides N-methylbenzothiazole-2-thione and benzimidazole-2-thione: implications with the mechanism of action of antithyroid drugs.

Reaction of N-methylbenzothiazole-2-thione (C8H7NS2 or NMBZT) with diiodine produced the charge-transfer (ct) complex [(NMBZT).I2] (1). NMBZT reacts with diiodine in the presence of FeCl3 in a molar ratio of 3:6:1 and forms the ionic complex [[(NMBZT)2I+].