Method of photopolymerization with complex metal chelate catalysts

In the photopolymerization of unsaturated monomers to form the corresponding polymers and copolymers the improvement wherein the polymerization is carried out upon exposure to light in the presence of Group IIIA catalyst in the form of a complex metal chelate having the structural formula ##STR12## in which M is a metal or metalloid selected from the group consisting of aluminum, gallium, indium, thalium and boron, X and Y are groups selected from the group consisting of sulphur, nitrogen, phosphorus, antimony, selenium and oxygen, Z.sub.1 and Z.sub.2 are groups selected from the group consisting of a halogen and substituted and unsubstituted alkyl, aryl, alkaryl, alkoxy, aryloxy, alkaryloxy and heterocyclic groups selected from the groups consisting of furyl, pyrryl, iodyl, pyrimidyl, pyridyl and furfuryl, R.sub.1 and R.sub.2 are groups selected from the group consisting of substituted and unsubstituted aryl, alkaryl, alkyl and alicyclic groups, n is a number of 1 to 3, and when n is 1, R.sub.1 may be a group having the general formula ##STR13## in which p is a number of 1 or 2 and R.sub.2, X and Y have the same meaning as defined above.