A MIXED-LIGAND ZINC(II) COMPLEX CONTAINING A BRIDGING DITHIOLATE LIGAND

The mixed-ligand Zn-II complex bis(mu-1,2-benzenedithiolato)- 1 kappa S, 1:2 kappa(2)S';2 kappa S, 1:2 S'-bis[(2,2'-bipyrimidine-kappa(2)N(1 ),N-1')zinc], [Zn-2(C6H4S2)(2)(C8H6N4)(2)]. containing benzenedithiola te (bdt) and 2,2'-bipyrimidine (bpyrm) has been synthesized and found to have the dinuclear formulation [Zn(bdt)(bpyrm)](2). The dinuclear c omplex has crystallographically imposed 1 symmetry with severely disto rted square-pyramidal coordination about the metal atoms. One S atom o f the bdt ligand bridges the Zn atoms in an asymmetric fashion [Zn S(1 ) 2.433 (3), Zn'-S(1) 2.475 (3) Angstrom] while the second S atom is b ound in a terminal mode at a shorter distance [Zn-S(2) 2.303 (3) Angst rom]. The formation of a bdt-bridged rather than a bpyrm-bridged speci es may be favored by a significant pi-stacking interaction between the phenyl ring of the bdt ligand and one ring of the bpyrm ligand.