Photoinduced Reactions of Tri-tert-butylindium with (Diethylamino)trimethylstannane and (Di-n-butylamino)trimethylstannane.

The preparations of [(t-Bu)(2)InNEt(2)](2) and [(t-Bu)(2)InN(n-Bu)(2)](2) by the photoinduced reactions of (t-Bu)(3)In with Et(2)NSnMe(3) and (n-Bu)(2)NSnMe(3), respectively, have been investigated. The isolation and characterization of products other than [(t-Bu)(2)InNR(2)](2) in these reactions clearly indicate that the reactions of (t-Bu)(3)In with R(2)NSnMe(3) do not proceed by simple alkyltrimethyltin elimination. A possible radical mechanism for the formation of the byproducts has been suggested. X-ray crystallographic studies indicate that both compounds are dimeric in the solid state. Crystallographic data: for [(t-Bu)(2)InNEt(2)](2), orthorhombic space group Pbca (No. 61), a = 19.135(7) Å, b = 19.670(6) Å, c = 15.793(7) Å, V = 5944.41(5) Å(3), rho(calcd) = 1.346 g cm(-)(3); for [(t-Bu)(2)InN(n-Bu)(2)](2), triclinic space group P&onemacr; (No. 2), a = 11.943(2) Å, b = 15.790(1) Å, c = 10.711(3) Å, alpha = 98.60(1) degrees, beta = 103.54(2) degrees, gamma = 94.85(1) degrees, V = 1926 Å(3), rho(calcd) = 1.232 g cm(-)(3). Mass spectrometry data indicate that both compounds exist as dimers in the gaseous state.

Theoretical study of reaction pathways to borazine.

Four reaction pathways from diborane and ammonia to borazine, (HBNH)3, have been studied computationally at the density functional level (B3LYP/6-311+G(2d,p)//B3LYP/6-31G(d)). The cycloaddition of H2BNH2 to 1,3-diaza-2,4-diborabuta-1,3-diene and subsequent elimination of two molecules of H2 was found to be the lowest-energy pathway to (HBNH)3. In the other pathways, the formation and conversion of the intermediates 1,3,5-triaza-2,4,6-triborahexatriene, cyclotriborazane, and 1,3,5-triaza-2,4,6-triborahexa-1,5-diene into (HBNH)3 were investigated. The formation of 1,3-diaza-2,4-diborabuta-1,3-diene and, subsequently, the formation and electrocyclization of 1,3,5-triaza-2,4,6-triborahexatriene and the cycloaddition of H2BNH2 to 1,3-diaza-2,4-diborabuta-1,3-diene are predicted to be the kinetically favored pathways to (HBNH)3 in the gas phase. At low concentrations of 1,3-diaza-2,4-diborabutene, high concentrations of H2BNH2, and a temperature of 298.15 K, the formation of the polyolefins H3BNH2(H2BNH2)nNHBH2 (n=1,2) is predicted to be competitive with the formation of 1,3-diaza-2,4-diborabuta-1,3-diene.