Chelated alkyl halide manganese complexes ( η5: η1-C 5H 4CH 2CH 2X)Mn(CO) 2 from photolysis of ( η5-C 5H 4CH 2CH 2X)Mn(CO) 3

Abstract

Manganese tricarbonyl complexes ( η 5-C 5H 4CH 2CH 2Br)Mn(CO) 3 ( 3) and ( η 5-C 5H 4CH 2CH 2I)Mn(CO) 3 ( 4), with an alkyl halide side chain attached to the cyclopentadienyl ligand, were synthesized as possible precursors to chelated alkyl halide manganese complexes. Photolysis of 3 or 4 in toluene, hexane or acetone-d 6 resulted in CO dissociation and intramolecular coordination of the alkyl halide to manganese to produce ( η 5: η 1-C 5H 4CH 2CH 2Br)Mn(CO) 2 ( 5) and ( η 5: η 1-C 5H 4CH 2CH 2I)Mn(CO) 2 ( 6). Low temperature NMR and IR spectroscopy established the structures of 5 and 6. Photolysis of 3 in a glass matrix at 91 K demonstrated CO release from manganese. Low temperature NMR spectroscopy established that the coordinated alkyl halide complexes are stable to approximately −20°C.