Reaction of ethyl diazoacetate with Co-3(CO)(9)(mu(3)-CCl): Isolation and X-ray structures of Co-3(CO)(9)(mu(3)-CCO2Et), Co-3(CO)(9)(mu(3)-CCH2CO2Et), and [Co-3(CO)(9)(mu(3)-CCHCO2Et)](2)

The reaction between the tricobalt cluster Co-3(CO)(9)(mu(3)-CCl) (1) and A lCl3, followed by treatment with ethyl diazoacetate, N2CHCO2Et, affords a c omplex mixture of products in low yields. Column chromatography has allowed the isolation of the four cluster compounds Co-3(CO)(9)(mu(3)-CH) (2), Co- 3(CO)(9)(mu(3)-CCO2Et) (3), Co-3(CO)(9)(mu(3)-CCH2CO2Et) (4), and [Co-3(CO) (9)(mu(3)-CCHCO2Et)](2) (5) Clusters 4 and 5 are new and have been fully ch aracterized in solution by IR and H-1 NMR spectroscopy. The molecular struc tures of clusters 3-5 have also been determined by single-crystal X-ray dif fraction analysis. Co-3(CO)(9)(mu(3)-CCO2Et) crystallizes in the triclinic space group <P(1)over bar>, a = 8.8393(5), b = 14.727(1), c = 15.272(1) Ang strom, alpha = 93.361(6), beta = 105.509(5)degrees, gamma = 100.336(6)degre es, V = 1872.6(2) Angstrom(3), Z = 4, and d(calc) = 1.823 g/cm(3). Co-3(CO) (9)(mu(3)-CCH2CO2Et) crystallizes in the monoclinic space group P2(1)/n, a = 9.3806(7), b = 9.2617(8), c = 22455(2) Angstrom, beta = 94.483(7)degrees, V = 1944.9(3) Angstrom(3), Z = 4, and d(calc) = 1.803 g/cm(3). [Co-3(CO)(9 )(mu(3)-CCHCO2Et)](2) crystallizes in the monoclinic space group C2/c, a = 21.585(2), b = 8.7977(7), c = 20.784(1) Angstrom, beta = 104.807(6)degrees, V = 3815.8(5) Angstrom(3), Z = 4, and d(calc) = 1.835 g/cm(3). Plausible p athways leading to the formation of clusters 2, 4, and 5 are discussed.