Reactions of Bis(triphenylphosphonio)isophosphindolide Salts with Mercury(II) Compounds: Coordination Induced Addition and Oxidation Reactions and Synthesis of a Monomeric 1:1 Complex of the Type [R(2)(R'O)P]HgBr(2).
Bis(triphenylphosphonio)isophosphindolide triflate (1[CF(3)SO(3)]) reacted with HgCl(2) and H(2)O or MeOH to give a phosphinito complex which was converted with excess HgCl(2) into the dimercury complex 5. In contrast, methanolysis of 1[X] (X = CF(3)SO(3), Br) in the presence of Hg(OAc)(2) afforded the phosphonium cation 9. A mercury complex 8 was isolated for X = Br as a reaction intermediate. Salts of a macrocyclic cation with a constitution similar to that of 9 were obtained by reaction of 1[CF(3)SO(3)] with Hg(OAc)(2) and triethylene glycol. The products were characterised by (1)H, (13)C, and (31)P NMR spectroscopy; in addition, (199)Hg NMR data of some complexes were obtained from 2D (31)P,(199)Hg shift correlations. Complexes 5 (space group P2(1)2(1)2(1), Z = 4, a = 12.449(2) Å, b = 17.583(3) Å, c = 23.111(3) Å, V = 5058.8(14) Å(3), 8917 reflections refined to R(w2) = 0.103) and 8 (space group C2/c, Z = 8, a = 20.028(2) Å, b = 15.513(2) Å, c = 30.247(8) Å, beta = 91.91(1) degrees, V = 9392(3) Å(3), 7955 reflections refined to R(w2) = 0.177) were further characterized by single crystal X-ray diffractommetry. Compound 8 is the first example of a monomeric complex of the type LHgX(2) (L = phosphine donor, X = halogen); formation of a halide bridged dimer is presumably prevented by the extraordinarily sterically demanding ligand. A reaction mechanism for the formation of 5 and 8 is proposed which involves the formation of mercury complexes of 1 as the initial step.
Gudat
Dietrich
D
Anorganisch Chemisches Institut der Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn.
Nieger
Martin
M
Schrott
Martin
M