Reactions of 1,8-Nonadiyne with Co₂(CO)₈ and Mo₂(C₅H₄R)₂(CO)₄ and Crystal Structures of [M₂L₂(CO)₄][μ-HC₂(CH₂)₅C₂H-μ][Mo₂(C₅H₄R)₂(CO)₄] (M = Co, L = CO; M = Mo, L = C₅H₄R, R = H, COCH₃, COOC₂H₅)

Abstract

The treatment of 1,8-nonadiyne with Co2(CO)8 in hexane at room temperature gives a new complex [Co2(CO)6][μ-HC2(CH2)5C2H-μ][Co2(CO)6] (1) followed by regioselective exchange reactions with Na[Mo(C5H4R)(CO)3] (R = H, COCH3, COOC2H5) to afford the hetero-tetranuclear clusters [Co2(CO)6][μ-HC2(CH2)5C2H-μ][CoMo(C5H4R)(CO)5] (2a, R = H; 2b, R = COCH3; 2c, R = COOC2H5) and [CoMo(C5H4R)(CO)5][μ-HC2(CH2)5C2H-μ][CoMo(C5H4R)(CO)5] (3a, R = H; 3b, R = COCH3; 3c, R = COOC2H5), respectively. The reaction of Mo2(C5H4R)2(CO)4 with 1,8-nonadiyne produces the homo-dinuclear clusters [HC2(CH2)5C2H-μ][Mo2(C5H4R)2(CO)4] (4a, R = H; 4b, R = COCH3; 4c, R = COOC2H5) and homo-tetranuclear clusters [Mo2(C5H4R)2(CO)4][μ-HC2(CH2)5C2H-μ][Mo2(C5H4R)2(CO)4] (5a, R = H; 5b, R = COCH3; 5c, R = COOC2H5), respectively. The clusters 4a, 4b, and 4c reacted with Co2(CO)8 to form the novel tetranuclear clusters [Co2(CO)6][μ-HC2(CH2)5C2H-μ][Mo2(C5H4R)2(CO)4] (6a, R = H; 6b, R = COCH3; 6c, R = COOC2H5). The structures of 5a, 5b, and 6a have been determined by single-crystal X-ray diffraction, and the regioselective exchange reactions have been briefly discussed.