Infrared-spectra and normal-coordinate analysis of quinoline and quinolinecomplexes

Normal coordinate analysis was performed on the vibrational spectra data of quinoline and the force field parameters of the free molecule were determi ned by the refinement of the corresponding parameters of benzene and pyridi ne molecules. The results of semiempirical (AM1) and ab initio (4-31G(*)) c alculations were taken into account during the refinement procedure. A part ially common and well-transferable force field has been obtained for free q uinoline. In order to investigate the coupling peculiarities of the vibrati onal modes of quinoline by metal-ligand vibrations, the calculated force fi eld parameters of the free ligand were used in calculating the IR spectra o f the transition metal (II) quinoline complexes, without any alterations an d only force field parameters related to the M-N(Q) bond were introduced. T he calculated spectra have been compared with the experimental spectra of t he quinoline metal (II) complexes. (C) 2001 Elsevier Science B.V. All right s reserved.