Coordination polymers and supramolecular cages based on [(MS4)Cux]x−2 cluster units and N-containing ligands

Abstract

We herein report five coordination polymers (CPs) and two supramolecular cages based on [MS₄Cu_x]^x−2 (M = W, Mo, x = 1, 2, … 6) units and N-containing ligands, 9,10-di(1H-imidazol-1-yl)anthracene (dia), 1,6-di(1H-imidazol-1-yl)pyrene (dip), and 1,1′,1′′-(benzene-1,3,5-triyltris(methylene))tris(1,4-diazabicyclo[2.2.2]octan-1-ium) bromide (bmd), and 1,1′,1′′-((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(1,4-diazabicyclo[2.2.2]octan-1-ium) (mbmd). Compounds 1 and 2 both contain the penta-nuclear [(WS₄)Cu₄]²⁺ cluster unit. The four Cu⁺ atoms were arranged in a distorted tetrahedron and rectangle around the (WS₄)²⁻ core in 1 and 2, respectively, affording a 3-connected unit in 1 and a 2-connected unit in 2. Compounds 3, 4 and 5 were built with the tri-topic organic ligand bmd; 3 and 4 contain penta-nuclear [WS₄Cu₄]²⁺ units, and 5 contains the hexa-nuclear [MoS₄Cu₅]³⁺ unit. However the connectives of the cluster units in 3, 4 and 5 and the final helical chain structures were similar. Compound 6 contains a tetra-nuclear [WS₄Cu₃I₃]²⁻ unit and positively charged mbmd ligand. The mbmd ligand was in a cis-conformation leading to a supramolecular cage, which accommodated an I⁻ anion as guest. Compound 7 is isostructural to 6 but contains a [WS₄Cu₃Cl₃]²⁻ cluster unit, mbmd ligand and a Br⁻ free anion. This work demonstrates that the number and arrangement of Cu⁺ around the (MS₄)²⁻ core can be varied with the synthesis conditions, affording heterothiometallic [(MS₄)Cu_x]^x−2 cluster units of versatile geometries and connectivities for building CPs.