Intermolecular alkane C-H bond activation with (OC)3Mn- and (OC)2Fe- negative ions in the gas phase

Only (OC) 2 Fe − reacted with CH 4 and (CH 3 ) 4 C to yield the respective hydridoalkyl adduct negative ions, specifically characterized with the neopentyl adduct. Both (OC) 3 Mn − and (OC) 2 Fe − reacted with the alkanes containing β-CH bonds to form (adduct −H 2 ) − product ions. The products from the reactions with C 2 H 6 were shown to be the (OC) n M(π-C 2 H 4 ) − complexes by the further ion/molecule reactions of the Mn complex: adduct formation with SiH 4 and (CH 3 ) 3 SiH, C 2 H 4 ligand substitution with SO 2 , and up to four H/D exchanges with D 2 . The H/D exchanges with D 2 established the reversibility of the β-hydride shifts occurring in intermediate metal complex negative ions. From the reaction efficiency (RE) for the C 2 H 6 reaction, RE/(1°C-H bond) was derived. The remaining (adduct −H 2 ) − product ions produced from the higher n-alkanes and the cycloalkanes were characterized as (OC) n M(H)(η 3 -C 3 H 3 R 2 ) − complexes produced by metal insertion into an allylic C-H bond in the intermediate olefin complexes