Crystal structure and low-temperature emission of [(dmp)Cu(μ-S₂butphos)₂Cu(dmp)][BF₄]₂·6CH₂Cl₂ (dmp=2,9-dimethyl-1,10-phenanthroline; S₂butphos=1,4-bis(diphenylphosphinesulfido)butane)

The synthesis and crystal structure of a bimetallic luminescent Cu(I) complex containing 1,4-bis(diphenylphosphinesulfido)butane and the α-diimine 2,9-dimethyl-1,10-phenanthroline (dmp) is described. The coordination geometry about the Cu(I) center is pseudo-tetrahedral. Interplanar interactions between phenyl groups on the phosphine sulfide ligands and the phenanthroline exist which are indicative of intramolecular π-stacking, leading to compressed S-Cu-S bond angles. The complex displays emission from a single metal-centered charge-transfer state at 77 K in a 4:1 ethanol/methanol (v/v) glass. This is in contrast to the triphenylphosphine complex, which exhibits dual luminescence from a charge-transfer and an intraligand state at 77 K. Crystal data: triclinic, {Mathematical expression}, a=13.619(4) Å, b=13.673(2) Å, c=15.384(2) Å, α=75.08(1)°, β=80.35(2)°, γ=80.67(2)°.