Synthesis and characterization of the first transition-metal fullerene complexes containing bis(η6-benzene)chromium moieties

While photochemical reaction of C-60 with an equimolar amount of Mo(Co)(4)(eta(6)-Ph2PC6H5)(2)Cr (1) in toluene at room temperature produced bimetallic Mo/Cr fullerene complex fac/mer-(eta(2)-C-60) Mo(CO)(3)(eta(6)-Ph2PC6H5)(2)Cr] (2) in 87% yield, the thermal reaction of an equimolar mixture of C-60, M(dba)(2) (M = Pd, Pt; dba = dibenzylideneacetone) and (eta(6) -Ph2PC6H5)2Cr (3) in toluene at room temperature afforded bimetallic M/Cr fullerene complexes (eta(2) -C-60)M[(eta(6) -Ph2PC6H5)(2)Cr] (4, M = Pd; 5, M = Pt) in 88% and 92% yields, respectively. Products 2, 4 and 5 are the first transition-metal fullerene complexes containing bis(eta(6)-benzene)chromium moieties. While 2, 4 and 5 were characterized by elemental analysis and spectroscopy, the crystal molecular structures of 4 along with the starting materials 1 and 3 have been determined by X-ray diffraction techniques. (c) 2005 Elsevier B.V. All rights reserved.