Triorganotin cyanometallate compounds

A compound of the general formula I ##STR7## wherein m is 4, 6 or 8

• n is 0 or 1,
• a is 0 or 1,
• b is 1, 2, 3, 4 or 5,
• each of
• R.sub.1, r.sub.2 and R.sub.3 independently represents an alkyl group of 1 to 18 carbon atoms, an alkenyl group of 2 to 18 carbon atoms, a cycloalkyl group of 5 to 12 carbon atoms, an alkylcycloalkyl group of 6 to 18 carbon atoms, or an aryl group of 6 to 16 carbon atoms which is unsubstituted or substituted by alkyl, alkoxy or alkylthio or oxoalkyl or carbalkoxyalkyl, each of 1 to 12 carbon atoms, or by 1 to 2 halogen atoms or by a nitro group, or an aralkyl group of 7 to 17 carbon atoms which is unsubstituted or substituted by alkyl of 1 to 12 carbon atoms or by 1 to 2 halogen atoms or by a nitro group,
• L represents NH.sub.3, pyridine, water, CO, NO or a halogen atom, and
• M if m is 4, represents Ni(O), Ni(I), Ni(II), Pd(II), Pt(II), Cu(I), Cu(II), Ag(I), Au(III), Zn(II), Cd(II), Hg(II), and if m is 6 represents Ti(III), V(II), V(III), Cr(I), Cr(II), Cr(III), Mn(I), Mn(II), MN(III), Te(I), Re(I), Re(II), Re(III), Re(IV), Fe(II), Fe(III), Ru(II), Ru(III), Os(II), Co(I), Co(II), Co(III), Rh(III), Ir(III), Pt(IV), and if m is 8, represents Ti(III), Mo(IV), Mo(I), W(IV), W(V), Mn(IV) or Re(V), and with the proviso that R.sub.1, R.sub.2 and R.sub.3 may not all be methyl or all be phenyl at the same time when M is Fe(II) or Fe(III).