The present invention is directed to novel organometallic complexes as catalysts for the reaction of compounds with isocyanate and hydroxyl functional groups to form urethane and/or polyurethane and the process employing such catalysts. More particularly, the present invention is directed to novel complexes of zinc(II) with substituted amidines. These novel catalysts are useful for the production of urethanes and polyurethanes which are important in many industrial applications.