Synthesis and characterization of Group 6 transition-metal [70]fullerene derivatives containing dppb ligands.: Crystal structure of fac-Mo(CO) 3(dppb)(CH 3CN)

Abstract

The thermal reaction of an equimolar quantity of fac-Mo(CO) 3(dppb)(CH 3CN) [dppb=1,2-bis(diphenylphosphino)benzene] ( 1) with C 70 in chlorobenzene at 80–85 °C gave an isomeric mixture of fac/ mer-Mo(CO) 3(dppb)(η 2-C 70) ( 2) in 46% yield, whereas the photochemical reaction of an equimolar amount of Mo(CO) 6, dppb and C 70 in chlorobenzene at room temperature afforded the isomeric mixture 2 in 48% yield and a single isomer mer-[Mo(CO) 3 (dppb)] 2(η 2,η 2-C 70) ( 3) in 19% yield. Similarly, while the thermal reaction of fac-W(CO) 3 (dppb)(CH 3CN) ( 4) with C 70 produced a single isomer mer-W(CO) 3(dppb) (η 2-C 70) ( 5) in 42% yield, the photochemical ‘one pot’ reaction of Cr(CO) 6, dppb and C 70 gave rise to a single isomer mer-Cr(CO) 3(dppb)(η 2-C 70) ( 6) in 62% yield and a single isomer [ mer-Cr(CO) 3(dppb)] 2(η 2,η 2-C 70) ( 7) in 25% yield, respectively. All the new [70]fullerene mono- and dinuclear organometallic derivatives 2, 3 and 5– 7 have been characterized by elemental analysis, and IR, 1H-, 31P-, 13C-NMR (partly), UV–vis and FAB-MS spectroscopic methods, as well as the crystal structure of one of their starting materials fac-Mo(CO) 3(dppb)(CH 3CN) ( 1) has been determined by X-ray diffraction analysis.