PULSE-RADIOLYSIS STUDIES OF DECACARBONYLDIMANGANESE(O) AND HALOPENTACARBONYLMANGANESE(I) - PENTACARBONYLMANGANESE(O) RADICAL

The pulse radiolysis of Mn2(CO)10, Mn(CO)sBr, and Mn(CO)5l in ethanol solution has been investigated. The Mn(CO)5- radical, which was observed, exhibits an optical absorption band with a maximum at 830 nm and a molar absorption coefficient of Є830=800±80 M-1 cm-1. Absolute rate constants were determined for the reactions of the solvated electron with Mn2(CO)10 (9.1ËŸ109 M_1 s-1), Mn(CO)5Br (1.0ËŸ1010 M-1 s-1), and Mn(CO)5I (1.02 X 1010 M-1s-1). For the iodide system, Mn(CO)5- is also formed by the reaction of α-ethanol radical with Mn(CO)5I (1.5 X 108 M_1 s-1)- The recombination of Mn(CO)5- has a rate constant of 2k=1.2ËŸ109 M_1 s_1; Mn2(CO)10 is identified as a final product in the radiolysis of the halide complexes. Mn(CO)5-reacts with O2 (1.8 ËŸ109 M-1 s_1). © 1978, American Chemical Society. All rights reserved.