Bis[2-((dimethylamino)methyl)ferrocenyl]lead, (FcN)₂Pb, as a Ligand:  Synthesis and Characterization of the Heterotrimetallic Metalloplumbylene Compounds (FcN)₂PbM(CO)₅ (M = Cr, Mo, W)

Abstract

The reaction of [Fe(η 5 -C 5 H 5 )(η 5 -C 5 H 3 (CH 2 NMe 2 )-2)- C,N ] 2 Pb, (FcN) 2 Pb ( 1 ), with the group 6 carbonyl derivatives M(CO) 5 L (M = Cr, W, L = THF; M = Mo, L = THF, NMe 3 ) affords the heterotrimetallic plumbylene adducts (FcN) 2 PbM(CO) 5 (M = Cr ( 2 ), Mo ( 3 ), W ( 4 )) in excellent yield. All compounds were characterized by elemental analysis, X-ray crystallography, and IR and 1 H and 13 C NMR spectroscopy. The results show that the metalloplumbylenes 2 − 4 exist solely as meso diastereomers, both in the solid state and in solution, although the starting compound 1 consists in solution of a mixture of two interconverting diastereomers, rac - and meso -(FcN) 2 Pb. The Pb−M bond lengths are indicative of some degree of π-bonding.