Structure and Magnetism of a New Dodecanuclear Cu^II Complex with Acetato and Imidazolato Bridges, Formed by Oxidation of the Chelating Ligand 1,1,7,7‐Tetrakis(imidazol‐2‐yl)‐2,6‐diazaheptane

Abstract

A novel dodecanuclear copper(II) complex [Cu 12 (tidhd) 4 -(MeOH) 8 (CH 3 COO) 8 ](MeOH) 0.8 (Htidhd = 1,1,7,7-tetrakis-(imidazol-2-yl)-2,6-diaza-1,6-heptadiene) with imidazolato and acetato bridging ligands was synthesized by reaction of polyimidazole 1,1,7,7-tetrakis(imidazol-2-yl)-2,6-diazaheptane (Htidahp) with copper acetate in a methanol solution. The complex crystallized in the triclinic space group P1 with a = 9.1204(1), b = 13.5139(2), c = 27.6925(5), α = 76.8006(6)°, β = 82.8066(7)°, γ = 76.4594(9)°, Z = 1. Structure analysis shows that the unit cell of the complex contains twelve copper(II) ions in three different coordination environments. The

Adipato‐Bridged Copper(II) Complexes

“…The apical ligating atoms are an aqua oxygen atom and an anti-syn bridging carboxylate oxygen atom, respectively, at Cu1 and Cu2. The equatorial Cu-N bond lengths in the range 1.980(3)-1.992(3) Å are shorter than those in 3, but they are comparable with the corresponding ones in [Cu 12 (tidhd) 4 (CH 3 OH) 8 (CH 3 COO) 8 ](CH 3 OH) 0.8 [Htidhd = 1,1,7,7-tetrakis(imidazol-2-yl)-2,6-diaza-1,6-heptadiene], [21] whereas the basal and apical Cu-O bond lengths vary in the ranges 1.931-1.962 and 2.214-2.498(3) Å, respectively, and are longer than the corresponding ones in 3. The τ (Addison) parameters of 0.20 (Cu1) and 0.13 (Cu2) indicate more significant Figure 4.…”

“…[16,17] Interestingly, research has indicated that carboxylate groups in the above-mentioned paddle-wheel-like tetracarboxylato-bridged copper(II) dimers could be pairwise replaced by bidentate N-donor aromatic ligands to form semi-paddle-wheel (SPW) dinuclear clusters, [18][19] which, through two anti-syn bridging carboxylate oxygen atoms, could be further condensed into double-semi-paddle-wheel (DSPW) tetranuclear copper(II) clusters (Scheme 1). [20][21] Such DSPW-like tetranuclear copper(II) clusters have been found in molecular complexes; [20][21] however, it is seldom that they have been used as SBUs to construct coordination polymers. Our recent investigations show that self-assembly of Cu II ions and adipate anions in the presence of 2,2-bipyridine (bpy) or 1,10-phenanthroline (phen) provides an efficient strategy for nucleation of DSPW-like tetranuclear copper(II) clusters, which can be bridged by adipato ligands to make up porous MOFs.…”