Yoshiyuki Hase

The vibrational spectra of phthalic anhydride

Abstract The IR and Raman spectra of phthalic anhydride have been reported for the polycrystalline sample and the polarized Raman spectrum for the molten sample. The observed frequencies have been assigned tentatively to the C2v molecular symmetry and a normal coordinate analysis has been carried out for a modified valence force field.

The infrared and Raman spectra of phthalimide, N-d-phthalimide and potassium phthalimide

Abstract The IR and Raman spectra of phthalimide, N-d-phthalimide and potassium phthalimide have been reported for polycrystalline samples and the observed bands have been discussed on the basis of a C 2v molecular symmetry. By comparison with the fundamental frequencies the assignment for phthalic anhydride has been reexaminad and the frequency shifts among four compounds have been discussed by considering the changing of bond nature. A normal coordinate analysas has been carried out to calculate the force constants of molecules and to confirm the band assignment.

Vibrational spectra of adducts of acetonitrile with titanium and tin tetb achloride

Abstract The IR and Raman spectra of the adducts of acetonitrile and acetonitrile- d 3 , with titanium and tin tetrachloride have been measured in the solid state. The observed spectra suggest a cis -configuration for these adducts, and tha vibrational assignments and the normal coordinate analyses have been performed on the basis of C 2v symmetry.

The infrared and Raman spectra of pyromellitic dianhydride

Abstract The infrared and Raman spectra of solid state samples of pyromellitic dianhydride have been measured. The infrared—Raman mutual exclusion rule has been observed and the frequencies have been tentatively assigned on the basis of D 2h symmetry. The values of the CO and skeletal ring stretching frequencies have been interpreted in terms of a conjugated π-system.

The Raman active vibrational modes and isotopic effects of four isotopically substituted lithium hydroxides

Abstract The Raman active vibrational fundamental modes of four isotopically substituted polycrystalline lithium hydroxides have been reported and the observed frequencies have been discussed in terms of the frequency ratios expected for the pure internal and lattice vibrations and the Teller-Redlich product rule.

The infrared and Raman spectra of tetrachlorophthalic anhydride, tetrachlorophthalimide, N-d-tetrachlorophthalimide and potassium tetrachlorophthalimide

Abstract The vibrational IR and Raman spectra of tetrachlorophthalic anhydride, tetrachlorophthalimide, N- d -tetrachlorophthalimide and potassium tetrachlorophthalimide have been measured for polycrystalline samples and the observed bands have been assigned tentatively by comparison with those of tetrahydro-compounds. To confirm the assignments, a normal coordinate analysis has been carried out on an assumption of the valence force field. The CO stretching modes of the OCXCO resonating system have been discussed in terms of the observed frequencies and the calculated force constants.

Conformational and electronic interaction studies of α-substituted carbonyl compounds. Part 9. ω-Hetero-substituted acetophenones

νCO frequencies and intensities, n→π*CO transition energies and α-methylene carbon chemical shifts were measured for some ω-hetero-substituted acetophenones (φCOCH2X: X = F, OMe, NMe2, NEt2, Cl, Br, SEt, and I), and their conformations were estimated with the help of molecular-mechanics calculations. The stability of the gauche rotamers is discussed in terms of hyperconjugative interactions between σCX and πCO* orbitals. The carbonyl frequency shifts of the cis rotamers are interpreted as due to the substituent field effect, while the corresponding shifts for the gauche rotamers have been ascribed to an interplay of the inductive and hyperconjugative effects. The abnormal negative νCOgauche shifts and the n→π*CO band bathochromic shifts of the ω-fluoro- and ω-methoxy-acetophenones, and the observed shielding effect on the α-methylene carbon atom of the studied acetophenones, are discussed in terms of π*CO/σCX and π*CO/X1p orbital overlapping. The higher stabilization of the ω-ethylthioacetophenone gauche rotamer, the largest negative νCOgauche shift, and the lower shielding effect for its methylene carbon have been interpreted as due to the simultaneous occurrence of π*CO/σCS and πCO/σCS orbital interactions.

Raman active normal vibrations of lanthanide oxychlorides

Abstract Raman spectra of solid state lanthanide oxychlorides, LnOCl, where Ln  La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er, have been measured in the 1000-40 cm −1 region and the observed fundamental wavenumbers have been assigned and discussed by referring to the results of the factor group analysis and the normal coordinate calculations based on a tetragonal space group D 7 4 h .

Infrared Active Frequencies for Lithium Hydroxide

Abstract The infrared active fundamental frequencies of 6LiOH, 6LiOD, 7LiOH and 7LiOD are reported for polycrystalline samples and discussed using the results of the factor group analysis for a D7 4h [tbnd] P4/nmm crystal structure and applying the Teller-Redlich product rule for the crystal vibrations.

Preferred conformations of methylthio-acetone and -acetophenone, methylsulphonyl-acetone and -acetophenone, from molecular-mechanics and dipole-moment techniques

Abstract Preferred conformations for the title compounds are determined from calculated molecular-mechanics energies in the gaseous phase and analysis of the dipole moments measured in solvents of low dielectric permittivity, In all cases, the gauche conformer having the MeS bond situated far away from the Me(C) (or Ph(C)) group, and nearly bisecting one of the C(O)CH valleys, is predominant.