CuX (X = Cl, Br, I) Containing Coordination Polymers Built Upon Isomeric RSCH2C≡CCH2SR (R = p-Tolyl, Benzyl) Dithioether Ligands: First Example of a Luminescent (CuCl)n/Dithioether Network

Abstract

The CuBr salt reacts with the acetylenic dithioether 1,4-bis(p-tolylthio)but-2-yne (L1) to generate the 1D [{Cu(μ2-Br)2Cu}(μ-p-MeC6H4SCH2C≡CCH2SC6H4Me-p)2] n coordination polymer (1), contrasting with the previously reported reaction with CuI, which provided a 2D network [{Cu4(μ3-I)4}(μ-p-MeC6H4SCH2C≡CCH2SC6H4Me-p)2] n . (JIOPM, 2014, 24, 190-200). The ribbons of 1 incorporate two different types of alternating centrosymmetric Cu(μ2-Br)2Cu rhomboids displaying loose Cu···Cu contacts of 2.9306(14) and 2.9662(14) A. The reaction of CuI and CuBr with the isomeric dithioether ligand 1,4-bis(benzylthio)but-2-yne (L2) yields the isomorphous dinuclear 0D complexes [{Cu(μ2-X)2Cu}(μ-PhCH2SCH2C≡CCH2SCH2Ph)2] (2a: X = I; 2b: X = Br). These species represent the first examples of dinuclear [S2{Cu(μ2-X)2Cu}S2] complexes spanned by a dithioether ligand. In contrast, treatment of CuCl with L2 gives rise to the formation of an unusual 2D coordination polymer [{Cu2(μ2-Cl)(μ3-Cl)}(μ-PhCH2SCH2C≡CCH2SCH2Ph)] n (3), in which the layers are assembled both by dative Cu–S thioether bonds and organometallic Cu-π-acetylenic interactions via the triple bond of the L2 ligand. Furthermore, the Cu(I) centers are interconnected through μ2- and μ3-bound chloro ligands. Finally, thermal stability and photophysical proprieties were studied. This investigation demonstrated the interesting luminescent behavior of CuCl-containing coordination polymer (3).