Synthesis, optical spectroscopy, structural, and DFT studies on dimeric iodo-bridged Copper(I)complexes

Three new iodo-bridged copper(I)complexes of the type [CuI(PPh₃)L]₂, where L = Ar–≡–C₅H₄N, Ar = phenyl (C₁), biphenyl (C₂)and flourenyl (C₃)have been synthesized via coordination-driven self-assembly processes. Two of Cu(I)complexes, C₂ and C₃, have been characterized by single-crystal X-ray diffraction studies. The complexes have two molecules of the P-donor ligand and two molecules of the N-donor ligand in trans configurations, supporting the central Cu₂I₂ unit. Absorption properties of the complexes have been investigated. Extensive DFT calculation has been carried out to delineate the influence of aromatic spacers on the optical properties and the nature of excited states. The ease of synthesis of these Cu(I)dimers and the wide range of ethynylpyridine supporting ligands that can be incorporated highlights the potential for these materials to form polymers by linking through the ethylylpyridine ligands.