title: Tetra-kis(μ(2)-2,2-dimethyl-propanoato-κO,O')bis-[(pyridine-κN)copper(II)]: a monoclinic polymorph.
abstract: The structure of the dinuclear title complex, [Cu(2)(C(5)H(9)O(2))(4)(C(5)H(5)N)(2)], represents a monoclinic polymorph of the previously reported triclinic form [Blewett et al. (2006 ▶). Acta Cryst. E62, m420-m422]. Each carboxyl-ate group is bidentate bridging and the distorted octa-hedral geometry about each Cu(II) atom is completed by a pyridine N atom and the other Cu atom [Cu⋯Cu = 2.6139 (7) Å]. In the crystal, mol-ecules are connected into supra-molecular chains via π-π inter-actions formed by the pyridine rings [centroid-centroid distance = 3.552 (3) Å] and these are connected into a two-dimensional array in the ac plane by C-H⋯π contacts. One of the tert-butyl groups is disordered over two orientations in a 0.734 (6):0.266 (6) ratio.
authors.affiliation: Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Lailatun Nazirah
authors.initials: LN
authors.lastname: Ozair
authors.forename: Norbani
authors.initials: N
authors.lastname: Abdullah
authors.forename: Hamid
authors.initials: H
authors.lastname: Khaledi
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink