104911-22-0Relevant academic research and scientific papers
Electroreduction of carbonylmanganese(I) cations. Mechanism of ligand substitution and hydride formation via manganese(0) intermediates
Narayanan,Amatore,Kochi
, p. 129 - 136 (2008/10/08)
Hydridomanganese(I) complexes (OC)3MnL2H are the principal products from a series of acetonitrile derivatives of carbonylmanganese cations, i.e., (OC)3Mn(NCMe)nL3-n+ (I), when the reductions are carried out electrochemically in the presence of added phosphines L. Cyclic voltammetric studies show that the conversion to the hydride can be formulated in three discrete stages. First, the carbonylmanganese cation such as (OC)3Mn(NCMe)3+ with n = 3 undergoes an electrocatalytic ligand substitution with added L to form the bis(phosphine) complex (OC)3Mn(NCMe)L2+ via labile 19-electron Mn(0) intermediates as in Scheme V. Second, the substitution product (OC)3Mn(NCMe)L2+ is reduced to the Mn(0) radical (OC)3Mn(NCMe)L2?; which is common to all cationic precursors irrespective of the degree of prior phosphine coordination in the precursor I (i.e., n = 1, 2). Third, the hydridomanganese product is derived by hydrogen atom transfer to the carbonyl ligand of the 19-electron intermediate (OC)3Mn(NCMe)L2? to form the formyl complex (OC)2Mn(NCMe)L2CHO, followed by the electrocatalytic extrusion of the coordinated ligand (MeCN) as in Scheme III. The third stage is established in the reductive conversion of the cationic (OC)4Mn(PPh3)2+ to the hydride (OC)3Mn(PPh3)2H by the observation of the intermediate (OC)3Mn(PPh3)2CHO during cyclic voltammetry. A competition to form the carbonylmanganate (OC)3MnL2- as a byproduct of reduction is also delineated.
