SYNTHESIS OF TRINUCLEAR MIXED-METAL CLUSTERS OS2FE(CO)(10)L-2 (L = OH, I, CO) - THE CRYSTAL-STRUCTURES OF OS2FE(CO)(10)(MU-OH)(2) AND OS2FE(CO)(12)CENTER-DOT-0.41OS(3)(CO)(12)

The heterometallic clusters Os2Fe(CO)(10)(mu-X)(2) (X = OH, I) were ob tained from the binuclear osmium complexes Os-2(CO)(6)X-n (X = Cl, n = 4; X = I, n = 2). The structure of Os2Fe(CO)(10)(mu-OH)(2) was determ ined by a single-crystal X-ray diffraction analysis. The crystal is tr iclinic and crystallizes in the space group P (1) over bar and a = 14. 009(6), b = 13.330(4), c = 9.511(2)Angstrom, (alpha = 103.69(2), beta = 81.83(3), gamma = 102.22(3)degrees, V= 1699(1)Angstrom(3), Z = 4, D- calc = 2.969 g cm(-3), R = 0.093 for 2359 independent reflections (F-o > 6 sigma(F-o)). The cluster consists of an open triangular OsFeOs me tal core with no Os-Os bond. The bridging OH groups are coordinated se miaxially and span the Os-Os edge. On heating in the presence of an ex cess of Fe-2(CO)(9), the Os-2 Fe(CO)(10)(mu-I)(2) cluster is converted to Os2Fe(CO)(12). The co-crystallate Os2Fe(CO)(12) . 0.41Os(3)(CO)(12 ) was isolated from the solution of Os2Fe(CO)(10)(mu-I)(2), as the pro duct of decomposition of the initial cluster. It crystallizes in the m onoclinic system, space group P2(1)/n, with a = 8.056(2), b = 14.743(2 ), c = 14.520(2)Angstrom, beta = 100.62(1)degrees V = 1695.0(5)Angstro m(3), Z = 4, D-calc = 3.179 g cm(-3) and R = 0.0250 for 1997 independe nt reflections (F-o > 4 sigma(F-o)). (C) 1997 Elsevier Science S.A.