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

The luminescent heteroleptic Cd(II) complex bis (-1,2-benzenedithiolato)-1 kS, 1:2 k²S 2 kS, 1:2 k²S-bis[(1,10-phenanthroline-k²N¹, N¹)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) Å, and = 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) Å) while the second S atom is bound in a terminal mode (Cd–S = 2.4955(5) Å). The mean interplanar spacing between the phen ligand and the phenyl ring of the bdt ligand is 3.291 Å while that between the phen ligands of adjacent molecules is 3.363 Å, suggesting the presence of both intra- and intermolecular -stacking. The complex is emissive in the solid state at room temperature (_em = 569 nm) with a luminecsent lifetime of 369 ns. The unstructured emission is believed to be a ligand-to-ligand –* charge transfer transition.