SYNTHESIS, CHARACTERIZATION, AND REACTIONS OF THE CLUSTER COMPLEXES CONTAINING THE TETRAHEDRAL CLUSTER CORE MFECOS (M=MO, W) AND A FUNCTIONALLY-SUBSTITUTED CYCLOPENTADIENYL LIGAND - THE SINGLE-CRYSTAL X-RAY STRUCTURES OF 2 DOUBLE CLUSTERS, [ETA(5)-C5H4C(O)CH2CH2C(O)C5H4-ETA(5)]-[M(CO)(2)FE(CO)(3)CO(CO)(3)(MU(3)-S)](2) (M=MO, W)

Reactions of monoanions eta(5)-RC(5)H(4)(CO)(3)M(-) with FeCo2(CO)(9)(mu(3)-S) gave the functional cluster complexes eta(5)-RC(5)H(4)(CO)(2)MFeCo (CO)(6)(mu(3)-S) (1a-e, M = Mo, R = CO(2)Me, CO(2)Et; M = W, R = CO(2)Me, CO(2)Et, C(O)Me). 1e reacted with MeMgI, followed by hydrolysis, giving tertiary alcohol cluster eta(5)-Me(2)C(OH)C5H4(CO)(2)WFeCo(CO)(6) (mu(3)-S) (2), while it reacted with NaBH4 to give the secondary alcohol cluster eta(5)-MeCH(OH)C5H4(CO)(2)WFeCo(CO)(6)(mu(3)-S) (3). Treatment of 3 with Et(3)OBF(4) afforded both a single cluster ether complex, eta(5)-MeCH(OEt) C5H4 (CO)(2)WFeCo(CO)(6)(mu(3)-S) (4), and a double cluster ether complex, eta(5)-C(5)H(4)MeCHOCHMeC(5)H(4) eta(5))[(CO)(2)WFeCo(CO)(6)(mu(3)-S)](2) (5) Similarly, reactions of dianions (-)M(CO)(3)[eta(5)C(5)H(4)C(O)CH2CH2C(O)C5H4-eta(5)](CO)(3)M(-) with two molecules of FeCo2(CO)(9)(mu(3)-S) gave 1,4-succinoyl(biscyclopentadienyl)-bridged double cluster complex [eta(5)-C5H4C(O)CH2CH2C(O)C5H4- eta(5)][(CO)(2)MFeCo(CO)(6)(mu(3)-S)](2) (6a, M = Mo, 6b, M = W). These complexes could be further reduced by NaBH4 to give dihydroxyl derivatives [eta(5)-C5H4CH(OH)CH2CH2CH(OH)C5H4 eta(5)][(CO)(2)MFeCo(CO)(6)(mu(3)-S)](2) (7a, M = Mo; 7b, M = W). Treatment of 7a and 7b with Et(3)OBF(4) afforded two unexpected double clusters containing a biscyclopentadienyl-substituted tetrahydrofuran bridge (alpha-eta(5)-C5H4-C4H6O-C5H4-eta(5)-alpha')[(CO)(2)MFeCo(CO)(6)(mu(3)-S](2) (8a, M = Mo, 8b, M = W). X-ray structures of 6a and 6b have been determined. Crystal data for 6a: triclinic, space group P-1 (No. 2), a = 7.602(3) Angstrom, b = 8.112(4) Angstrom, c = 16.208(3) Angstrom, alpha = 97.58(3)degrees, beta = 94.05(2)degrees, gamma = 109.50(3)degrees, V = 927(1) Angstrom(3), Z = 1. Crystal data for 6b: monoclinic, space group C2/c (No. 15), a = 26.448(7) Angstrom, b = 91660(4) Angstrom, c = 14.687(5) Angstrom, beta = 100.72(2)degrees, V = 3687(4) Angstrom(3), Z = 4.