New basic organic complexes containing zinc

摘要

The invention comprises co-ordination complexes of a zinc salt of an acid selected from thio- and dithio-phosphoric acids thio- and dithiophosphinic acids and thio- and dithio-carbamic acids wherein R and R1 are hydrocarbon or substituted hydrocarbon radicals which may be the same or different, and X is oxygen or sulphur with a heterocyclic tertiary amine in which one N atom is common to two rings, or with a heterocyclic ditertiary amine in which the N atoms which may or may not be in the same ring are separated from one another either by two or three carbon atoms. The radicals R and R1 may be alkyl, cycloalkyl, aryl, or aralkyl or an alkyl group interrupted by one or more hetero atoms, e.g. oxygen or sulphur, or R and R1 may together form an alkylene radical which may be interrupted by a hetero atom such as O or S and which together with the remainder of the thio acid molecule will form a ring structure containing from 4 to 7 atoms in the ring, e.g. the radical -(CH2)4- or -CH2CH2OCH2CH2-. The complex may comprise the combination of either (a) one or two molecules of the zinc compound with one molecule of the amine or (b) one molecule of the zinc compound with two molecules of the amine. The complexes may be obtained by mixing together solutions or suspensions containing the appropriate molecular proportions of the zinc compound and the amine and if necessary heating the mixture under reflux. Suitable solvents include acetone, petroleum ether, toluene and cyclohexanone. Specified tertiary amines are quinuclidine, 1:4-diaza-bicyclo-[2,2,2]-octane, pyrrolizidine, 7-oxal-1-aza-bicyclo-[4,3,0]-nonane and specified ditertiary amines are 4-dimethyl (or -di-n-butyl) aminopyridine, 4-morpholino pyridine, 4-pyrrolidinopyridine, N,N1-dimethylpiperazine, 1:10-phenanthroline, 2,21-dipyridyl and N,N1-dimethyl-1:4-diazacycloheptane. In one of the examples given zinc diphenyldithiophosphinate is first reacted with pyridine to form a 1:1 molar complex and the latter is then converted to the 4-dimethylaminopyridine complex by reacting the pyridine complex suspended in dry chloroform with 4-dimethylaminopyridine. The products are useful as antioxidants and as catalysts in the production of urethanes from organic isocyanates and hydroxy compounds.