Photochemistry of [Fe(CO)4L] complexes (L = NMe3 or pyridine) in argon and xenon matrices. Evidence for the formation of C3v[Fe(CO)3L] and the reversible infrared-induced isomerization to Cs[Fe(CO)3L]

Abstract

Photolysis of [Fe(CO)₄L] complexes (L = NMe₃ or pyridine) in Ar and Xe matrices at 10 K with the wavelengths 229, 254, 280, 313, 334, 366, 405, 436, and 475 nm resulted in the formation of C_3v[Fe(CO)₃L]. The reaction is reversed by i.r. light and by annealing the matrix. The C_3v[Fe(CO)₃L] complex isomerizes into C_s[Fe(CO)₃L] after i.r. photolysis. The reverse reaction is accomplished by excitation with visible light. Two forms of C_3v[Fe-(CO)₃L] are detected, which are called ‘reversible’ and ‘irreversible’C_3v[Fe(CO)₃L]. An explanation is given for the observed photochemical reactions based on photoelectron spectroscopy data.