Y. Yamaguchi, C. Kutal
Jan 29, 2000
Citations
1
Influential Citations
33
Citations
Journal
Macromolecules
Abstract
Spectroscopic, photochemical, and photoinitiation studies are reported for a series of monobenzoylferrocenes and 1,1‘-dibenzoylferrocenes. These nonionic metallocene complexes absorb strongly in the ultraviolet and visible wavelength regions owing to electronic transitions of mixed ligand field/charge-transfer character. Irradiation of the complexes in methanol results in ring−metal cleavage to yield a benzoyl-substituted cyclopentadienide carbanion and the corresponding half-sandwich iron(II) complex. This process occurs with an appreciable quantum efficiency (>0.30 at 546 nm) for 1,1‘-dibenzoylferrocenes; in contrast, monobenzoylferrocenes are appreciably less photosensitive. When the solvent is neat ethyl α-cyanoacrylate, the photogenerated carbanion initiates rapid anionic polymerization of this electrophilic monomer. Several factors that can influence the performance of benzoyl-substituted ferrocenes as anionic photoinitiators are considered.