Formation of [CuSCN]n-Based Topological Structures via a Family of Flexible Benzimidazolyl-Based Linkers with Different Spacer Lengths

Solvothermal reactions of bulk CuSCN with six flexible benzimidazolyl-based ligands with different spacer lengths [bzim)(CH2) (bzim)] (bzim = benzimidazolyl; n = 1, mbbm; a = 2, ebbm; a = 3, prbbm; n = 4, bbbm; n = 5, pbbm; a = 6, hbbm) afforded a series of new [CuSCN](n)-supported coordination polymers, [(CuSCN)(2)(mbbm))(n), (1), [(CuSCN)(2)-(ebbm)(2)] (2), [(Cu(SCN)(2)(prbbm)] (3a), [{(CuSCN)(2)(prbbm)(2)}center dot 2MeCN](n) (3b). [(CuSCN)(4)(bbbm)(3)](n) (4), [(CuSCN)(2)(pbbm)](n) (5), and [(CuSCN)(2)(()hbbm)](n) (6), respectively. Compounds 1-6 were characterized by elemental analysis. IR, and X-ray crystallography. Compound 1, 3a, or 6 possesses the similar staircase-like [CuSCNL chains that are bridged by mbbm, prbbm, or hbbm to form one one-dimensional (ID) chain with an oblong channel (3a) or two two-dimensional (2D) networks (1 and 6). Compound 2 or 3b consists of a dimeric [CuSCN], fragment that serves either as a 4-connecting node to link the other four equivalent ones via two pairs of ebbm bridges to form a 2D (4,4) network (2) or as a 2-connecting node to bridge its two adjacent ones via a pair of prbbm bridges to form a 1D chain (3b). Compound 4 contains a new kind of [CuSCN] double chain that is connected by bbbm with two conformations to form a unique 2D network, while 5 consists of a [CuSCM single chain that is linked by pbbm to form the other kind of 1D chain with an oblong channel. In addition, the photoluminescent properties of 1-6 in solid state at ambient temperature were also investigated.