Abstract: A method of producing an adduct of an organometallic compound M(R.sup.1).sub.3 where M is either indium or gallium and (R.sup.1).sub.3 represents a plurality of organic radicals which may be the same or different, preferably methyl or ethyl groups, comprising electrolysing, using a sacrificial anode of the metal M, a solution containing components 1 and 2 as follows:component 1: one or more organomagnesium halide compounds R.sup.1 MgX where X is a halide radical selected from Cl, Br and I; where R.sup.1 represents one of the groups contained in (R.sup.1).sub.3 ;component 2: a polar aprotic liquid which is a solvent for component 1, e.g. tetrahydrofuran, diethyl ether, di-isopentyl ether, di-n-butyl ether, diphenyl ether or anisole.Preferably, the solution electrolysed additionally contains a third component, component 3, which is one or more organic halides R.sup.1 X.sub.A, where R.sup.1 is one of the groups contained in (R.sup.1).sub.3, X.sub.

Abstract: A method of producing an adduct of an organometallic compound M.sup.1 (R.sup.1).sub.x, where M.sup.1 is a Group II or Group III metallic element and R.sup.1).sub.x represents a plurality of organic radicals, which may be the same or different, x being an integer equal to the valency of M.sup.1, comprises electrolysing, using a sacrificial anode of the metal M.sup.1, a solution containing components A, B and C as follows:A: a magnesium compound MgR.sub.2.sup.1 ;B: a readily ionizable support electrolyte providing relatively large anions and cations;C: a polar aprotic liquid which is a solvent for both components A and B; the metal M.sup.1 being selected from the group consisting of: indium, gallium, cadmium.