Synthesis, Characterization and Electrocatalysis of Phenyl-Functionalized Diiron Propanediselenolato Complexes

Reaction of 2-phenyl-1,3-dibromopropane with in situ generated Na2Se2 gave 4-phenyl-1,2-diselenolancyclopentane, which subsequently underwent the oxidative addition with Fe-3(CO)(12) yielding the diiron diselenolato complex [(mu-SeCH2)(2)CHC6H5]Fe-2(CO)(6) (1). Substitution of one or two carbonyls of complex 1 for triphenylphosphine (PPh3) or cis-1,2-bis(diphenylphosphine)ethylene (cis-dppv) in the presence of decarbonylating agent Me3NO center dot 2H(2)O afforded the PPh3-monosubstituted complex [(mu-SeCH2)(2)CHC6H5]Fe-2(CO)(5)(PPh3) (2) or the dppv-disubstituted complex [(mu-SeCH2)(2)CHC6H5]Fe-2(CO)(4)(kappa (2)-dppv) (3). The structures of the four compounds were fully characterized by elemental analysis and various spectroscopic methods and for complexes 2 and 3 by X-ray crystallography. The cycle voltammetry under different conditions, such as CF3COOH, MeCN or CH2Cl2, potential scan rate and temperature, was investigated.