Conformational preferences of isostructural N-methylpiperidine betaine and (1methylcyclohexyl)acetic acid studied by PM3 and B3LYP calculations. The effect of electrostatic interactions on the rotation barrier

In the course of vibrational spectroscopic investigations of DNA-metal interactions, the FTIR spectra of protiated and iminodeuterated solid tetrakis(imidazole)copper(II) acetate were recorded at room temperature and the boiling temperature of liquid nitrogen (RT and LNT, respectively) and studied together with its RT Raman spectrum. Bands due to the internal vibrations of the acetate groups and imidazole ligands, are assigned and correlated with the available structural data.