SYNTHESIS AND STRUCTURES OF BORON AND GERMANIUM CONTAINING 8-MEMBERED SILOXANE RINGS AND OF A BICYCLOHEPTANE DERIVATIVE WITH SILICON, TIN, AND OXYGEN AS BUILDING UNITS OF THE RING-SYSTEM

The reaction of (t-Bu)2Si(OH)2 with PhBCl2 and GeCl4, respectively, leads in a molar ratio of 1:1 to the formation of 1,3,5,7-tetraoxa-2,6-disila-4,8-diborocine 1 and 1,3,5,7-tetraoxa-2,6-disila-4,8-digermocine 2. Mu-O-O'-Di(t-butyl)silandiyl-dihydroxo-di-mu-hydroxohexachloro-distannane 3 has been synthesized by treatment of SnCl4 with (t-BU)2Si(OH)2 in CH2Cl2. The X-ray structure analyses of 1 and 2 exhibit eight-membered rings containing silicon, boron, oxygen, and silicon, germanium, oxygen. 1 and 2 crystallize in the triclinic space group P1BAR with a = 8.727(2), b = 9.523(3), c = 9.816(4) angstrom; alpha = 91.81(2), beta = 100.76(3), gamma = 116.90(1)-degrees and a = 8.297(2), b = 9.325(2), c = 10.900(2) angstrom; alpha = 72.36(1), beta = 77.48(1), gamma = 88.31(1)-degrees. The X-ray structure analysis of 3 exhibits a [3.1.1]bicycloheptane analogue structure. 3 crystallizes in the monoclinic space group P2(1)/c with a = 15.185(3), b = 14.302(3), c = 22.825(5) angstrom; beta = 90.84(3)-degrees.