Crystal structure of catena-poly[hemi[1,3-bis-(2,6-diisoprop-ylphenyl)imidazolium] [[μ3-acetato-κ(3) O:O:O'-tri-μ2-acetato-κ(6) O:O'-dicopper(II)(Cu-Cu)]-μ-chlorido] di-chloro-methane sesqui-solvate]

Acta Crystallogr E Crystallogr Commun. 2015 Jul 25;71(Pt 8):m148-9. doi: 10.1107/S2056989015013675. eCollection 2015 Aug 1.

Abstract

The title copper(II) complex, {(C27H37N2)[Cu4(CH3COO)8Cl]·3CH2Cl2} n , is a one-dimensional coordination polymer. The asymmetric unit is composed of a copper(II) tetra-acetate paddle-wheel complex, a Cl(-) anion situated on a twofold rotation axis, half a 1,3-bis-(2,6-diisoprop-ylphenyl)imidazolium cation (the whole mol-ecule being generated by twofold rotation symmetry) and one and a half of a di-chloro-methane solvent mol-ecule (one being located about a twofold rotation axis). The central metal-organic framework comprises of a tetra-nuclear copper(II) acetate 'paddle-wheel' complex which arises from the dimerization of the copper(II) tetra-acetate core comprising of three μ2-bidentate acetate and one μ3-tridentate acetate ligands per binuclear paddle-wheel complex. Both Cu(II) atoms of the binuclear component adopt a distorted square-pyramidal coordination geometry (τ = 0.04), with a Cu⋯Cu separation of 2.6016 (2) Å. The apical coordination site of one Cu(II) atom is occupied by an O atom of a neighbouring acetate bridge [Cu-O = 2.200 (2) Å], while that of the second Cu(II) atom is occupied by a bridging chloride ligand [Cu⋯Cl = 2.4364 (4) Å]. The chloride bridge is slightly bent with respect to the Cu⋯Cu inter-nuclear axis [Cu-Cl-Cu = 167.06 (6)°] and the tetra-nuclear units are located about a twofold rotation axis, forming the one-dimensional polymer that propagates along [101]. Charge neutrality is maintained by the inclusion of the 1,3-bis-(2,6-diisoprop-ylphenyl)imidazolium cation within the crystal lattice. In the crystal, the cation and di-chloro-methane solvent mol-ecules are linked to the coordin-ation polymer by various C-H⋯O and C-H⋯Cl hydrogen bonds. There are no other significant inter-molecular inter-actions present.

Keywords: coordination polymer; copper(II) tetra­acetate; crystal structure; imidazolium; paddle-wheel; paramagnetism.