Organometallic compounds and polymers made therefrom

A controlled release composition comprising an active agent and a compound of formula (I) ##STR19## wherein L.sup.1 is an element of Groups 13-16 of the Periodic Table;

• L.sup.2 is a neutral ligand;
• M is a transition element or a metal element of Groups 13-16 of the Periodic Table;
• n represents the number of coordination sites of M;
• x represents the oxidation state of M,
• R.sup.1 a polymerizable group;
• R.sup.2 and R.sup.1 are independently selected from the group consisting of an alkyl of up to 15 carbons;
• aryl of up to 30 carbons;
• an alkoxy or thioalkyl of up to 15 carbons;
• an aryloxy or thioaryl of up to 20 carbons;
• an oxygen or sulfur containing heterocycle of up to 25 carbons;
• an amine;
• an nitrogen heterocycle of up to 25 carbons with the proviso that L is not N;
• or R.sup.2 and R.sup.3 having the same definitions as above, interconnect to form a chelating ligand;
• R.sup.4 is an anionic ligand and when x is greater than 1, each R.sup.4 is the same or different;
• and
• m is 1, with the proviso that m is 2 when M is Cu, x is 1, L.sup.1 is phosphorus, L.sup.2 is not present and R.sup.4 is cyanate;
• and m is 3 when M is Cu, x is 1, L.sup.1 is phosphorus, L.sup.2 is not present, and R.sup.4 is an thioalkyl having up to 15 carbons or an thioaryl having up to 25 carbons;
• and also with the proviso that when M is Rh, R.sup.1 is a polymerizable group having a -(.dbd.CH.sub.2) group.