H. Vogt, D. Wulff-molder, M. Meisel
1996
Citations
0
Influential Citations
3
Citations
Journal
Zeitschrift für Naturforschung B
Abstract
(p-Bromobenzyl)triphenylphosphonium Bromide, [(p-Br-C6H4-CH2)P(C6H5)3]+Br- · (CH2Cl2)2.5 (1) has been prepared by the reaction of triphenylphosphine with p-bromobenzylbromide and its structure determined (triclinic, space group P1̅, Z = 2, a = 1198.03(12), b = 1245.80(11), c = 1258.42(12)pm, a = 100.170(8), β = 103.543(9), γ = 1 18.158(7)°. The compound exists as Br- anions and [(p-Br-C6H4- CH2)P(C2H5)3]+ cations, with weak interactions between the chlorine atoms of the CH2Cl2 molecules and the bromine bonded in the cation. [p-Br-C6H4-CH2)P(C6H5)3]Br2 (2) and [(p-Br-C6H4-CH2)P(C6H5)3]Br3·(CH2Cl2)1.5 (3) have been obtained by reactions of the corresponding amounts of bromine with 1 in methylenechloride solution. The yellow-red crystals of 2 are orthorhombic, space group Pccn, Z = 8, a = 2060.8(3), b = 1223.6(4), c = 1860.8(3) pm. Compound 2 exists as [p-Br-C6H4-CH2)P(C6HO5)3]+ cations and linear Br2-4 units with a bromide-bromine distance of 297.3(4) pm. The red crystals of (3) are triclinic, space group P1̅, Z = 2, a = 1 171.16(7), b = 1260.97(8), c = 1270.35(7)pm, α = 65.510(5), β = 75.811(5), γ = 62.320(5)°, and contain [(p-Br-C6H4-CH2)P(C6H5)3]+ cations and linear, slightly asymmetrical Br-3 anions. In all cases the cation has a slightly irregular tetrahedral geometry around the P atom.