Comprehensive Investigation of the Electronic Spectroscopy and Theoretical Treatments of Ferrocene and Nickelocene

Abstract

New data concerning the electronic absorption and emission spectra of ferrocene and the absorption spectrum of nickelocene are presented. Assignment and discussion of the transitions are made based on the experimental results. No ferrocene emission is observed upon excitation into the lowest energy absorption band. An emission occurs upon excitation into the next higher energy band. These results are interpreted in terms of crossing of the first excited state and the ground state. The luminescence is long lived and is interpreted as phosphorescence paralleling an assigned singlet‐triplet absorption at 5280 A. No nickelocene emission was noted. Assignments of the absorption bands of ferrocene and nickelocene are proposed within the framework of each of the major theoretical approaches.