Cuprous Halide Complexes of a Variable Length Ligand: Helices, Cluster Chains, and Nets Containing Large Solvated Channels

Abstract

The variable-length azacrown ether bridging ligand N,N′-bis(3-pyridyl-methyl)diaza-18-crown-6 (b3pmdc) was reacted with cuprous iodide to give a range of new discrete and polymeric coordination compounds. Six structurally diverse CuI(b3pmdc) architectures were isolated, as well as a single oxidized CuII(b3pmdc) species. These include the helical one-dimensional (1D) chain [H4b3pmdc][Cu10I14]·CHCl3·2H2O (1), the luminescent linear cluster chain [Cu4I6(H2b3pmdc)] (2), the guest water containing network [Cu4I4(Hb3pmdc)2](1.5ClO4)(0.5I3)·3.5H2O·2.5MeOH (3), the luminescent cubane cluster chain [Cu4I4(b3pmdc)2] (4), the three-dimensional (3D) net [Cu9I12(Kb3pmdc)3(H2O)4]·9MeOH (5), the dinuclear mixed halide [Cu2Cl3.4I2.6(H4b3pmdc)] (6), and the cupric 1D chain [CuCl2(H2b3pmdc)(MeOH)2]·2Cl·2MeCN (7). Manipulation of the ligand conformation was achieved by the addition of the alkali metal salt potassium and by varying the pH of the solution with a range of acids (HCl, HClO4). In the case of 2 and 4, green and yellow luminescent emission was observed, as a result of the varied metal environment.