SYNTHESIS OF AN AZADISILACYCLOPROPANE AND 2 CYCLODISILAZANES FROM 1,1,2,2-TETRACHLORO-1,2-DIMESITYLDISILANE

1,1,2,2-Tetrachloro-1,2-dimesityldisilane (1) was synthesized from 2.1 equiv of MesLi.Et2O and Si2Cl6. Reaction of 1 with two MesNHLi at -78 -degrees-C in THF afforded trans-2-chloro-1,2,3,4-tetramesitylcyclodis ilazane (4a), 21%, cis-2-chloro- 1,2,3,4-tetramesitylcyclodisilazane ( 4b), 4 %, and esitylamino)-1,2,3-trimesitylazadisilacyclopropane (5), 26%. When 1 equiv of MesNHLi was used, 1, 4a, and 4b were the major sp ecies present. Use of 4 equiv of MesNHLi led mainly to the formation o f 5 (80%). The molecular structure of 5.2C6H6 was determined by X-ray crystallographic analysis. Compound 5-2C6H6 crystallized in the monocl inic space group C2/c with cell parameters a = 21.887(6) angstrom, b = 12.364(3) angstrom, c = 18.878(5) angstrom, beta = 101.44(2)-degrees, V = 5007(2) angstrom3, Z = 4, d(calcd) = 1.131 g/cm3, and R = 4.98%.