Synthetic, Spectroscopic, and Electrochemical Studies of the Isomerically-Rich [M(CO)2(P2P′)X] /0 (M = Mn, Re; X = Cl, Br; P2P′ = η3-Ph2P (CH2)2P(Ph)(CH2)2PPh2) System: Structural Characterization of a Novel Pair

Abstract

Reaction of Mn(CO)5X (X = Cl, Br) with Ph2P(CH2)2P(Ph)(CH2) 2PPh2 (P2P') in refluxing xylene led to the formation of isomerically pure cis,mer-Mn(CO)2(η3-P2P/)X. Cyclic voltammograms in dichloromethane (0.1 M Bu4NPF6) show a reversible one-electron oxidation (process 1, E1/2 = 0.142 V) to give cis,mer-[Mn(CO)2(P2P')X]+, However, in acetone (0.1 M Bu4NPF6) at room temperature, process 1 is not reversible and an additional redox process 4 (E1/2 = 0.048 V) is observed. Process 4 is not observed at low temperatures, and at higher temperatures in acetone it merges with process 1 and also a new reversible redox couple (process 5, E1/2 = -0.411 V) appears. A combination of electrolyses, chemical ox..