Bis(acetato-κ2 O,O′)bis[4-(dimethylamino)pyridine-κN]copper(II)

In the mononuclear title complex, [Cu(CH3COO)2(C7H10N2)2], the CuII ion, located on a crystallographic inversion centre, is six coordinated by two N atoms of two 4-(dimethylamino)pyridine (DMAP) ligands in apical positions and four O atoms from two symmetry-related opposite acetate anions, which are asymmetrically bonded in the equatorial plane. The complex and the crystal packing of the complex are stabilized by intra- and intermolecular C—H⋯O hydrogen bonds, giving R 4 2(10) rings and generating a layer-like structure.


Comment
Lewis based coordinated Cu II carboxylate complexes are an important class of coordination compounds due to their relevance as structural and functional models for biologically important metalloenzymes (Lippard & Berg,1994). Anionic carboxylates are highly flexible and versatile O-donor ligands since a range of substituents may be introduced on the alkyl chain to modulate their reactivity and coordination propensity, and result in a variety of coordination modes such as monodentate, bidentate bridging, chelating, monoatomic bridging and chelating bridging (Deacon & Phillips, 1980). The Lewis base 4-Dimethylaminopyridine (DMAP) is a derivative of pyridine that is widely used in hypernucleophilic acylation for a variety of reactions, such as esterifications with anhydrides. We report herein on the molecular structure of a novel
In the crystal, the packing is consolidated by C-H···O interactions involving aromatic H-atoms (Table 1, Fig 2), in which R 4 2 (10) (Bernstein et al.,1995) hydrogen-bonded rings are formed, generating a two-dimensional layer-like structure.

Experimental
To a solution of Cu(CH 3 CO 2 ) 2 .H 2 O (0.2 g, 1 mmol) in methanol (40 cm 3 ) at room temperature was added solid 4-(Dimethylamino)pyridine (DMAP) (0.122 g, 1 mmol) in small portions under constant stirring. the mixture was then filtered and the filtrate allowed to stand for 20 days, after which small blue block-like crystals of the title complex were obtained.
They were filtered and dried under vacuum.

Refinement
All the C-bound H-atoms were located in difference Fourier maps but were treated as riding on their parent atoms: C-H = 0.917 -0.974 Å with U iso (H) = 1.2U eq (C-aromatic) or U iso (H) = 1.5U eq (C-methyl).