Promoting Alkane Binding: Crystallization of a Cationic Manganese(I)‐Pentane <i>σ</i> ‐Complex from Solution

Abstract

Abstract Transition metal–alkane σ ‐complexes are key intermediates in C–H activation and, until now, analysis of these species has been restricted to either the solution OR the solid state. Here we present a synthetic methodology that converts Mn 2 (CO) 10 in a noncoordinating solvent environment to [Mn(CO) 5 ] + at room temperature, and this species binds n ‐pentane as the strongest interacting ligand available. Three isomers of the n ‐pentane σ ‐complexes were studied in detail by solution NMR‐spectroscopy at low temperature. Two isomers of [Mn(CO) 5 ( n ‐pentane)] + crystallize from solution at room temperature and their structures were determined by single crystal X‐ray crystallography. The oxidation of metal complex dimers in solution to generate reactive metal cations, which bind alkanes as the strongest available ligand, is a new and probably general approach to generate metal‐alkane σ ‐complexes.