Architectural Diversity for Anion-Mediated Self-Assembly of Four Pairs of Silver(I) Polymeric Isomers Having Linear and V-Shaped Imidazole/Thiophene/Imidazole Bridging Spacers

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A pair of linear and V-shaped acceptor–donor–acceptor (A–D–A) thiophene-based diazole structural isomers [i.e., 2,5-di(1H-imidazol-1-yl)thiophene (L1) and 3,4-di(1H-imidazol-1-yl)thiophene (L2)] have been used as bidentate bridging ligands to build Ag(I) fluorescent and semiconducting coordination polymers in the presence of different counterions. X-ray single-crystal diffraction analyses for eight complexes 1–8 reveal that they are four pairs of polymeric isomers formulated as {[Ag(L1)(CF3COO)]}n (1), {[Ag(L2)(CF3COO)]}n (2), [Ag(L1)(NO3)]n (3), {[Ag(L2)(NO3)]·(H2O)}n (4), [Ag(L1)(ClO4)]n (5), {[Ag(L2)](ClO4)}n (6), {[Ag(L1)(CH3CN)](PF6)}n (7), and {[Ag(L2)](PF6)·(CH3CN)}n (8). They exhibit abundant structural diversity, namely, a one-dimensional (1D) dimeric chain 1, a double-strand helix 2, a cosinelike chain 3, wavelike chains 4 and 8, linear chains 5 and 7, and a zigzag chain 6 because of the alterations of conformation for μ2 bridging ligands L1 and L2 (cis/cis, cis/trans, and trans/trans) and the participancy of different counterions (CF3COO–, NO3–, ClO4–, and PF6–). It is noted that weak Ag(I)–thiophene coordinative bonds are observed in the case of 7 with the Ag–S distance of 3.057(4) Å, which lead to a 13.8× enhancement of solid-state conductivity in comparison with the semiconducting single crystal of 8 at room temperature.