Song Li-Cheng

The study of isolobal displacement reactions. Synthesis and structures of the heterobimetallic μ-alkyne cluster complexes η-RC5H4(CO)2M(μ-R1C2R2)Co(CO)3 (MMo, W; RCH3C(O), CH3O2C)

η-CH3C(O)C5H4(CO)2Mo(μ-C6H5C2C6H5)Co(CO)3 (1a),η5-CH3C(O)C5H4(CO)2Mo(μ-p-CH3C6H4C2C6H5)Co(CO)3 (1b), η5-CH3O2CC5H4(CO)2Mo(μ-C6H5C2C6H5)Co(CO)3 (1c), η5-CH3C(O)C5H4(CO)2W(μ-C6H5C2C6H5)Co(CO)3 (1d) and η5-CH3O2CC5H4(CO)2W(μ-C6H5C2C6H5)Co(CO)3 (1e) were prepared by reactions of the corresponding sodium salts of functionally substituted cyclopentadienyl carbonyl molybdenum (tungsten) anions with (CO)3Co(μ-C6H5C2C6H5)Co(CO)3 or (CO)3Co(μ-p-CH3C6H5C2C6H5)Co(CO)3, respectively. The compounds 1a-1e were characterized by elemental analysis, IR, 1H NMR and mass spectroscopy, while the structure of 1c was further established by X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P21/n with a = 8.503(1), b = 26.721(7), c = 11.033(2) A; β = 106.09(2)°; V = 2408 A3; and Z = 4.

Synthesis and characterization of homo- and heterobimetallic complexes [η5-RC5H4W(CO)2]2 (WW) and η5 -RC5H4(CO)3WCo(CO)4 (WCO). X-ray molecular structure of [η5-EtO2CC5H4W(CO)2]2

Abstract The thermal decarbonylation of metal-metal singly bonded complexes [η 5 -RC 5 H 4 W(CO) 3 ] 2 in diglyme affords, in 23–34% yields, the corresponding triply bonded dimer [η 5 -RC 5 H 4 W(CO) 2 ] 2 ( 1 ) (R  MeCO, MeO 2 C, and EtO 2 C). Further reaction of 1 (R  MeCO and MeO 2 C) with Co 2 (CO) 8 in toluene at ambient temperature produces the heterobimetallic compounds η 5 -RC 5 H 4 (CO) 3 WCo(CO) 4 ( 2 ) (R  MeCO and MeO 2 C) in 51 and 40% yields, respectively. Structures for all these compounds have been deduced from elemental analysis, IR, 1 H NMR and MS spectroscopies and the structure of 1 (R  EtO 2 C) has been unequivocally confirmed by single crystal X-ray diffraction analysis.