UV Photochemistry of [CpFe(CO)₂]₂ (Cp = η⁵-C₅H₅) Studied by Picosecond Time-Resolved Infrared Spectroscopy

Abstract

Picosecond time-resolved infrared spectroscopy has been used to investigate the primary UV photochemistry of [CpFe(CO)2]2 (Cp = η5-C5H5) in alkane solution at room temperature. We show that the triply bridged intermediate, CpFe(μ-CO)3FeCp, is formed within 10 ps. We observe a new intermediate with a ν(CO) band at 1908 cm-1 that reacts at a diffusion-controlled rate (k = (1.3 ± 1.0) (2σ) × 1010 s-1) with THF to form Cp(CO)Fe(μ-CO)2Fe(THF)Cp.