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Mixed quantum mechanics/molecular mechanics (QM/MM) techniques are used for exploring several feasible low-energy pathways of the nucleotide transfer reaction of pol [beta] for correct G:C basepairing versus the incorrect G:G case. The results have helped in interpreting the nucleotide specificity differences across polymerase families in terms of the concept of active site preorganization.

The molecular structures of gaseous CH3AsF2 and (CH3)2AsF were determined by electron-diffraction experiments and ab initio computations. Findings indicated that both As-C and As-F bond lengths are shortened by increasing numbers of fluorine atoms but that the angles CAsF and FAsF are almost invariant in the series (CH3)3As, (CH3)2AsF, CH3AsF2, and AsF3.

A study has been conducted to examine the structure of perfluorocyclopropene, a perfluorinated compound, in gaseous, solution and crystalline states using electron diffraction, rotational spectroscopy and liquid crystal NMR spectroscopy, respectively. X-ray diffraction techniques were also used to measure crystal growth. The structural parameters for the solid and gas phases are presented.

Electron diffraction, ab initio and IGLO computations analyze the molecular structure of 1-(difluoroboryl)pentaborane(9), demonstrating high thermal stability in the gas phase. A difluoroboryl group replaced the apical boron atom of the molecule, which comprised a pentaborane(9) cage. The exo B-B bond was the center of rotation for the BF2 moiety.

An analysis of the C-C ring opening reaction of the oxirane molecule on the singlet potential energy surface, in the context of ab initio electronic structure theory, identified three minima on the surface relating to the closed-shell ring structure (as reactant), and two closed-shell open structure (as products) of C2 and Cs symmetry. Four authentic transition states on the associated reaction coordinates connect these minima.