Electronic structure of axially distorted molybdenum(V) complexes; an absorption spectral study

Abstract

Electronic absorption spectra of a range of molybdenum(V) complexes and [WOCl₄(H₂O)]^– have been measured in the temperature range 4.2–300 K and in the energy range 4 000–40 000 cm^–1. The absorption bands below 18 000 cm^–1 have been assigned to the one-electron promotion d_xy*→d_xz*, d_yz*. Bands in the visible region have been classified as type I (d_xy*→d_x²–y²*) or type II (in-plane ligand-to-metal charge transfer). Assignments of the absorption spectra of the chromophores MoO³⁺, VO²⁺, WO³⁺, MoN²⁺, RuN³⁺, and OsN³⁺ have been compared to produce a self-consistent assignment.