Photochemical Generation of Cyclopentadienyliron Dicarbonyl Anion by a Nicotinamide Adenine Dinucleotide Dimer Analogue

Irradiation of the absorption band of an NAD (nicotinamide adenine dinucleotide) dimer analogue, 1-benzyl-1,4-dihydronicotinamide dimer, (BNA)2, in acetonitrile containing a cyclopentadienyliron dicarbonyl dimer, [CpFe(CO)2]2, results in generation of 2 equiv of the cyclopentadienyliron dicarbonyl anion, [CpFe(CO)2]-, accompanied by the oxidation of (BNA)2 to yield 2 equiv of BNA+. The studies on the quantum yields, the electrochemistry, and the transient absorption spectra have revealed that the photochemical generation of [CpFe(CO)2]- by (BNA)2 proceeds via photoinduced electron transfer from the triplet excited state of (BNA)2 to [CpFe(CO)2]2.