Infrared spectroscopic studies of transition metal complexes and polarizability effect

The literature data on substituent influence on the CS, CN, NC, NN, and NO stretching frequencies (ν) in the IR spectra and in specific cases on their respective stretching force constants (k) have been analyzed for 28 series of the transition metal complexes. The ν and k values were first established to depend not only on the inductive and resonance effects but on the polarizability of substituents as well. The contribution of the polarizability effect varies from 0 to 57% with the type of series.

Graphical abstractThe properties P (ν, k) of the transition metal complexes (CS, CN, NC, NN, NO stretching frequencies ν in IR spectra, force constants k) depend on joint influence of the inductive, resonance, and polarizability effects of X substituents.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► IR spectra of transition metal complexes. ► CS, CN, NC, NN, and NO frequencies and force constants. ► The influence of the inductive, resonance and polarizability effects of substituents.