A luminescent heteroleptic five-coordinate cadmium(II) complex containing a bridging dithiolate ligand

Abstract

The luminescent heteroleptic Cd(II) complex bis (μ-1,2-benzenedithiolato)-1 kS, 1:2 k 2 S′ 2 kS, 1:2 k 2 S′-bis[(1,10-phenanthroline-k 2 N 1, N 1′)cadmium], [Cd2(C6H4S2)2(C12H8N2)2], containing benzenedithiolate (bdt) and 1,10-phenanthroline (phen) has been synthesized and found to have the dinuclear formulation [Cd(bdt)(phen)]2. The complex crystallizes in the space group P21/n with a = 10.3400(4), b = 11.5110(4), c = 13.6230(5) A, and β = 106.828(2)°. The dinuclear complex has crystallographically imposed centrosymmetry with one S atom of the bdt ligand bridging the Cd atoms in an asymmetric fashion (Cd–S = 2.5743(5) and 2.6817(5) A) while the second S atom is bound in a terminal mode (Cd–S = 2.4955(5) A). The mean interplanar spacing between the phen ligand and the phenyl ring of the bdt ligand is 3.291 A while that between the phen ligands of adjacent molecules is 3.363 A, suggesting the presence of both intra- and intermolecular π-stacking. The complex is emissive in the solid state at room temperature (λem = 569 nm) with a luminecsent lifetime of 369 ns. The unstructured emission is believed to be a ligand-to-ligand π–π* charge transfer transition.