The preparation of disubstituted derivatives of [B3H8]- with halogen or pseudo-halogen is reported. Ions studied include [B3H6Cl2]- (1), [B3H6Cl(NCS)]- (2), [B3H6Cl(NCBH3)]-, and [B3H6Cl(NCBH2Cl)]-. N.m.r. parameters show that the ions are fluxional in solution, and 11B-11B coupling is poorly resolved. The thermal stabilities, and chemical and electrochemical behaviour of representative compounds are described. The molecular structures, illustrated by [B3H6Cl2]- and [B3H6Cl(NCS)]- relate to that of [B3H8]- with trans substituents. Four molecules of [N(PPh3)2][B3H6Cl2] crystallise in space group P21/c with a = 10.9552(14), b = 12.840(9), c = 24.236(5) Å, and β = 92.298(13)°. R = 0.0728 for 3 267 data measured at room temperature. The [B3H6Cl2]- ion has effective C2 symmetry and markedly asymmetric H bridges. [N(PPh3)2][B3H6Cl(NCS)] crystallises from CH2Cl2 as a 1:1 solvate with Z = 2 in space group P1, with a = 11.2855(22), b = 14.4000(21), c = 15.708(4) Å, α = 120.680(17), β = 109.760(18), and γ = 65.971 (14)° at 185 ± 1 K. An approximate structure solution affords R = 0.1922 for 5 706 diffraction data.
|Number of pages||9|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 1984|
ASJC Scopus subject areas