Synthesis and characterization of novel double tetrahedral transition metal clusters

The reaction of Co-2(CO)(8) and [Cl3CC(O)OCH2](2) gave a novel double tetra hedral cluster compound ([(CO)(9)Co-3 (mu(3)-C)C (O)OCH2](2) 1) containing two tetrahedral skeletons (Co3C) linked by a C(O)OCH2CH2OC(O) bridge. The r eaction of 1 with different molecular ratios of Na[M(CO)(3)C5H4R][M =Mo, W; R=H, C(O)Me] gave the one-step exchange products (CO)(9)Co-3 (mu(3)-C)C(O) OCH2CH2OC (O) (mu(3)-C)Co2M(CO)(8)(C5H4R) [M = Mo, R=H (2); M=Mo, R=C(O)Me (3)( M=W, R=H (4); M=W, R=C(O)Me (5)] or the two-step exchange products C(C 5H4R) (CO)(8)Co2M(mu(3)-C)C(O)OCH2](2)[M =Mo, R=H (6); M = Mo, R=C(O)Me (7) ; M=W, R=H (8); M=W, R=C(O)Me (9)]. By treating 5 or 9 with Na[Mo(CO)(3)C5H 5] in 1/2 molecular ratio, the compound (C5H5)(CO)(8)Co2MO (mu(3)-C) . C(O) OCH2CH2OC(O) (mu(3)-C)CoMoW (CO)(7)(C5H4C(O)Me) (C5H5)(10) or C(C5H5)(C5H4 . C(O)Me) (CO)(7)CoMoW (mu(3)-C)C(O)OCH2](2)(11) which has one or two chira l tetrahedral skeletons (CoMoWC)was obtained. Compounds 1-11 were character ized by C/H analyses, IR and H-1 NMR. The results indicate that the Co(CO)( 3) group in different cluster cores has a different reactivity in a metal e xchange reaction. The crystal structure of compound 1 was determined by sin gle-crystal X-ray diffraction methods. The crystal belongs to monoclinic sy stem with space group, P2(1)/n (# 14) and lattice parameters, a=0.933 0(2) nm, b= 1.519 7(4) nm, c = 1.178 3(4) nm, beta = 91.16(2)degrees, Z = 2, F(0 00)=972.