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

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.

有机金属合成子反式-[对甲硫基苯基乙炔基-铂(三甲基膦)₂-乙炔基对甲硫基苯基]（L1）与CuX（X=Cl、Br、I）在丙腈（PrCN）和苯甲腈（PhCN）中反应，生成具有极高结构可变性的一维（1D）或二维（2D）配位聚合物（CP）。该类配位聚合物的铜卤结构单元可为菱形Cu₂X₂二聚体片段，或是阶梯状立方烷型Cu₄I₄簇；其可结合或不结合结晶溶剂分子，且溶剂分子可与铜中心配位或不配位。
研究通过X射线单晶衍射、热重分析（TGA）、红外光谱（IR）、吸收与发射光谱，以及有无结晶溶剂时的光物理测试对产物进行了表征。采用密度泛函理论（DFT）与含时密度泛函理论（TDDFT）计算阐明了单重态与三重激发态的本质，结果表明激发态主要为ππ*跃迁，同时伴随少量MLCT（Cu₄I₄ → L1）电荷转移贡献。材料的孔隙性能通过BET测试（77 K下氮气吸附）进行了评估。无溶剂的一维配位聚合物不易吸附溶剂分子或二氧化碳（CO₂）；而二维配位聚合物在去除结晶溶剂后，其网格结构中存在明确的空腔，因此对二氧化碳的吸附效率最优。