Articles

Structure and Vibrational Frequencies of Vanadium(V) oligomers: an ab initio study using effective core potentials. Abstract Ab initio molecular geometries and vibrational frequencies of various isolated vanadate species (VO3−4, HVO2−4, H2VO−4, and V2O4−7) were calculated using different pseudopotentials. The relative merits of these were assessed by comparing the calculated molecular parameters with the corresponding values…

Ab initio SCF MO calculations on triaza and tetraaza cyclic amines. Abstract Molecular orbital ab initio calculations have been performed on some triaza and tetraaza cyclic amines aiming at the determination of their minimum energy geometries and of the relative conformational energies in different protonation states.The results clearly show two factors governing the conformational preferences…

Conformational equilibria for 3-methylstyrene: Raman and FTIR spectra and ab initio calculations. Abstract The Raman spectra of liquid 3-methylstyrene show pairs of bands whose temperature-dependent intensities clearly suggest the occurrence of a conformational equilibrium. From these bands, assigned to cis and trans conformers, a trans-cis energy difference of 0.8 + 0.2 kJ mol−1 was obtained…

β-cyclodextrin complexes of benzaldehyde, vanillin and cinnamaldehyde: a Raman spectroscopic study. Abstract Raman spectra of benzaldehyde, vanillin and trans-cinnamaldehyde, and of their complexes in β-cyclodextrin are presented and discussed. The guest molecules provide both an aromatic ring for privileged interaction with the cyclodextrin cavity, and characteristic vibrations (e.g., vC=O, vC=C, vCCϕ (ϕ=phenyl), vC-Hϕ) with group…

Discovery of two rotational isomers of 4-methoxystyrene by laser induced fluorescence in a supersonic jet. Abstract The S1–S0 fluorescence excitation spectrum of 4-methoxystyrene seeded into a supersonic free jet shows two 000 bands, corresponding to the cis and trans rotational isomers. Dispersed fluorescence, with excitation in each of these bands, show that some of the…