Luminescent 1D- and 2D-Coordination Polymers Using CuX Salts (X = Cl, Br, I) and a Metal-Containing Dithioether Ligand.

Abstract

The organometallic synthon trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) reacts with CuX (X = Cl, Br, I) in PrCN and PhCN to form 1D- or 2D-coordination polymers (CP) with a very high degree of variability of features. The copper-halide unit can be either the rhomboids Cu2X2 fragments or the step cubane Cu4I4. The CP's may also incorporate a crystallization solvent molecule or not, which may be coordinated to copper or not. Their characterizations were performed by X-ray crystallography, thermal gravimetric analysis (TGA), and IR, absorption, and emission spectra as well as photophysical measurements in the presence and absence of solvent crystallization molecules. The nature of the singlet and triplet excited state was addressed using DFT and TDDFT computations, which turn out to be mainly ππ* with some minor MLCT (Cu4I4 → L1) contributions. The porosity of the materials has been evaluated by BET (N2 at 77 K). The solvent-free 1D CP's are not prone to capture solvent molecules or CO2, but the efficiency for CO2 absorption is best for the 2D CP, which exhibits the presence of clear cavities in the grid structure, after the removal of the crystallization molecules.