HIGH-YIELD SYNTHESIS AND CHARACTERIZATION OF SN-6(MU(3)-O)(4)(MU(3)-OSIME(3))(4) - A NOVEL MAIN-GROUP CLUSTER FOR THE SUPPORT OF MULTIPLE TRANSITION-METAL CENTERS

A high yielding, highly reproducible synthesis of the novel main group cluster Sn-6(mu(3)-O)(4)(mu(3)-OSiMe(3))(4) (2), which involves the t hermolysis of bis[bis(trimethylsilanolato)tin] (4) at 180 degrees C, i s reported. Spectroscopic and chemical analyses are fully consistent w ith the assigned structure of 2. A preliminary investigation of the re action between this compound and Fe-2(CO)(9) reveals that the tin(II) centers of the former are capable of participating as 2e sigma-donors in the formation of the Fe(CO)(4) adducts, [{Fe(CO)(4)} Sn-6(mu(3)-O)( 4)(mu(3)-OSiMe(3))4] (5) and Fe(CO)(4)}Sn-2(6)-(mu(3)-O)(4)(mu(3)-OSiM e(3))(4)] (6). The assigned structures of 5 and 6 are confirmed by spe ctroscopic and crystallographic analyses and the latter reveal importa nt information regarding the influence that the steric features of 2 h ave on the coordination sphere of transition metal centers that are li gated to it. Space-filling models also reveal that additional complexa tion to 2, 5, and 6 is sterically permitted. Together? these findings provide an important platform upon which a variety of future studies t hat utilize 2 as a new class of building block for the construction of mixed p-d metal compounds and materials can be based. Single crystals of 5 are (at 25 degrees C) monoclinic, space group P2(1)/n with a 13. 404(2) Angstrom, b = 16.964(3) Angstrom, 17.766(2) Angstrom, beta = 90 .384(12)degrees, V = 4039.7(10) Angstrom(3), and Z = 4 (D-calcd = 2.13 9 mg m(-3); mu(Mo K alpha) = 41.57 mm(-1)). Single crystals of 6 .(0.7 )1/2C(6)H(6) are (at 23 degrees C) monoclinic, space group P2(1)/n wit h a = 11.804(2) Angstrom, b = 17.489(3) Angstrom, c = 23.222(2) Angstr om, beta = 97.146(9)degrees, V = 4756(1) Angstrom(3), and Z = 4 (D-cal cd = 2.089 mg m(-3); mu(Mo K alpha) = 38.41 mm(-1)).