Syntheses and Characterizations of the Novel Dodecanuclear Heterobimetallic Cage Clusters: [Et(4)N](2)[(M(2)Cu(2)S(2)O(2)edt(2))(3)(&mgr;(6)-S(2))].CH(2)Cl(2) (M = Mo, W; edt = (-)SC(2)H(4)S(-)).