Metal–α,ω-Dicarboxylate Complexes. II. catena-Poly[bis(imidazole-N³)copper(II)-di-μ-adipato(1 –)-O¹:O⁶;O⁶:O¹]

The structure of the title compound, [Cu(C₆H₉O₄)₂(C₃H₄N₂)₂]_n, is polymeric, joining two Cu^II-trans(imidazole)₂ units by two extended adipate monoanions. The metal ion at the centre of symmetry has a highly distorted octahedral coordination; the two longer bonds are formed to the protonated carboxylate O atoms [Cu1—O3 = 2.499 (2) Å] and the octahedron is completed by bonds to two imidazole N atoms and two deprotonated carboxylate groups. The `building block' of the polymer is an 18-membered ring of maximum dimensions 10.61 Å and 5.61 Å. Their molecular packing in space group C2/c, however, prevents channel formation of this size. The polymeric chains of the acid form very strong intramolecular hydrogen bonds via O3—H...O2 across the metal centre.

-1