Syntheses and crystal structures of tris(di-n-propylamino)-p-bromobenzyl-phosphonium bromides: [(C3H7)(2)N](3)PCH2C6H4Br+Br- and [(C3H7)(2)N](3)PCH2C6H4Br+Br3-

Tris(di-n-propylamino)-p-bromobenzylphosphonium bromide [(C3H7)(2)N](3)PCH2 C6H4Br+-Br- (1) has been prepared by the reaction of tris(di-n-propylamino) phosphine with p-bromobenzylbromide in methylene chloride. The: colorless c rystals are monoclinic, space group P2(1), Z = 2, a = 930.2(3), b = 1501.2( 3), c = 1093.5(2) pm, beta = 105,97(4)degrees. The lattice con tains Br- an ions and [(C3H7)(2)N](3)PCH2C6H4Br+ cations. [(C3H7)(2)N](3)PCH2C6H4Br+Br3- (2) has been obtained by treating 1 with equimolar quantities of elemental bromine in methylene chloride solution. The yellow-red crystals of 2 are t riclinic, space group <P(1)over bar>, Z = 2, a = 1069.5(3), b = 1267.7(7), c = 1273.7(3) pm, alpha = 87.27(3), beta = 82,67, gamma = 67.15 degrees, an d consist of [(C3H7)(2)N](3)PCH2C6H4Br+ cations and linear Br-3(-) anions. The three N atoms in the cations of 2 are planar.