Crystal structure of bis(m-phthalato- k3O,O':O'')[1,1'-(1,10-decanediyl) bis(imidazole)- k2N:N']dicobalt(II), Co2(C8H4O4)2(C16H26N4)

Abstract

Source of materialAm ixture of CoCO 3 (11.9 mg, 0.10 mmol), m-phthalic acid (16.6 mg, 0.10 mmol), 1,1'-(1,10-decanediyl)bis(imidazole) (L, 27.4 mg, 0.10 mmol), and water (7 mL) was sealed in aTeflonlined reactor (15 mL), heated at 120°Cfor 60 hand then gradually cooled to room temperature. Pink block-shaped crystals were obtained. Experimental detailsAll hydrogen atoms on carbon atoms were generated geometrically and refined as riding with d(C-H) =0 .93 -0 .97 Å and U iso (H) =1.0 -1.2 U eq (C). The Hatoms of C13 are not included in the model. The disordered Catoms (C14, C15, C16) were refined using split over two sites with occupancies of 0.64 and 0.36. DiscussionMetal-organic coordination polymers have attracted considerable attention because of their variety of topologies [1]. In this regard, agreat many metal-polycarboxylate compounds displaying various frameworks from 1D to 3D have been designed and characterized [2]. However, in comparison with the wide exploration of metal-polycarboxylate compounds based on rigid ligands, such as 4,4'-bipyridine, the ones constructed from relatively flexible N-donor bridging ligands have not been well investigated [3]. In our previous work,we have reported aseries of fascinating archetypal structures based on 1,1'-(1,4-butanediyl)bis(imidazole), 1,1'-(1,5-pentanedidyl)bis(imidazole), and 2,2'-bis(1H-imidazolyl)ether ligand, but carboxylate polymers related to 1,1'-(1,10-decanediyl)bis(imidazole) ligand (L) are relatively rare [4]. In the title crystal structure, each Co II cation is coordinated by three Oatoms from three m-phthalate (m-BDC) anions and one N atom from one Lligand in atetrahedral manner. One carboxylate group of the m-BDC anion acts in am onodentate coordination mode, while the other one in abidentate bridging mode. In this mode, the m-BDC anions link the Co II cations to at wodimensional layer, where four m-BDC anions and four Co II cations form af our-membered ring. The Ll igands, acting as bidentate bridging ligands, further extend the two-dimensional layer to furnish athree-dimensional framework. Due to the long skeleton of the Lligand, the final three-dimensional framework has large cavities, which offers the possibility of interpenetration of the structure. As aresult, two topologically identical networks give athree-fold interpenetrated framework.