Intraligand vibrations

In spite of the general insensitivity of the intraligand, vibrational modes to cluster size, there are a few specifics worth mentioning, particularly with respect to vc=c (ignoring effects of coupling with 6chj... 

Three broad classes of vibrational modes may contribute to the thermally averaged Franck-Condon factor the high-frequency (fast) modes hv > 1000 cm ) which are mainly intraligand vibrations, intermediate modes (1000 cm > hv > 100 cm ) that typically include the metal-ligand stretching vibrations and higher frequency solvent orientational-vibrational modes, and the low-frequency (slow) modes hv < 100 cm ) which are primary solvent modes but can include low-frequency intramolecular modes. At ordinary temperatures hv kT k hv hv and the low-frequency modes can be treated using classical (continuum) expressions. 

Identification of ligands coordinated to metal center determination of metal-ligand and intraligand vibrational modes bond strengths from force constants... 

Two other copper complexes, mononnclear [Cn(acac)(phen)(H20)]C104 and onedimensional polynuclear [Cu(acac)(bipy)(C104)] , have square-pyramidal structure. The latter complex has fragments bridged by perchlorate anions resulting in nentral polynn-clear chains. The solid-state spectra exhibit a broad d-d band and intraligand tt-tt transitions. IR data show that C—O vibrations correspond to a very strong intensity band at 1585 cm , as well as 1578 and 1525 cm . ... 

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