Verfahren zur Darstellung von Oniumsalzen mit komplexem Anion

Onium salts having a complex anion are prepared by the reaction of (a) an electron donor compound of formula R1kHlkY, (b) a electron acceptor compound of formula MR11nX1mn and (c) an organic compound RX, wherein R, R1 and R11 are alkyl or aryl groups, X is halogen, pseudohalogen or an acid residue, X1 is halogen or hydrogen, Y is N, P, As, Sb, Bi, S, Se or Te, M is Be, Zn, Cd, B, Al, In, Ga, Tl, Si, Ge, Pb or Sn, l and m are integers representing the capacities of Y and M respectively to combine with hydrogen, and k and n are 0 or an integer from 1 to l or m respectively. The reaction in its simplest form may be represented by:-D + A + RX --> [DR]+[AX]-wherein D represents the electron donor and A the electron acceptor, but compounds formed by the reaction of two molecules of acceptor with one each of donor and RX ar also disclosed. The reaction may be carried out by first forming a co-ordination compound between donor and acceptor and reacting this with RX, or an adduct or mixture may be formed from the acceptor and RX which is then reacted with the donor, or the donor and RX may be first mixed and then reacted with the acceptor. Trimethylammonium triethylchloroaluminate obtained by first passing triethylamine gas into triethylaluminium to form a 1 : 1 complex and passing methyl chloride into the product. By passing further methyl chloride there is obtained the complex Triethylpropylstibonium triethylbromoindanate is prepared by reacting methylantimony and triethylindium under an inert gas and adding N :propyl bromide to the product. Further examples are indicated by the equations:- The complex onium salts may be degraded by such methods as solvolysis with methanol or water, oxidative cleavage or displacement with a stronger complexing agent for the acceptor compound to give the simple onium salt (DR)+X- where D represents the donor compound. For example, tetraethylstibonium triethyl bromoaluminate in solution in dichloromethane is added to methanol, ethane is evolved and aluminium methoxide removed by decantation, and the residue worked up to yield tetraethylstibonium bromide.