Syntheses of Two New 1D and 3D Networks of Cu(II) and Co(II) Using Malonate and Urotropine as Bridging Ligands: Crystal Structures and Magnetic Studies

Citations Over TimeTop 10% of 2003 papers

Abstract

Two new metal-organic based polymeric complexes, [Cu(4)(O(2)CCH(2)CO(2))(4)(L)].7H(2)O (1) and [Co(2)(O(2)CCH(2)CO(2))(2)(L)].2H(2)O (2) [L = hexamethylenetetramine (urotropine)], have been synthesized and characterized by X-ray crystal structure determination and magnetic studies. Complex 1 is a 1D coordination polymer comprising a carboxylato bridged Cu(4) moiety linked by a tetradentate bridging urotropine. Complex 2 is a 3D coordination polymer made of pseudo-two-dimensional layers of Co(II) ions linked by malonate anions in syn-anti conformation which are bridged by bidentate urotropine in trans fashion. Complex 1 crystallizes in the orthorhombic system, space group Pmmn, with a = 14.80(2) A, b = 14.54(2) A, c = 7.325(10) A, beta = 90 degrees, and Z = 4. Complex 2 crystallizes in the orthorhombic system, space group Imm2, a = 7.584(11) A, b = 15.80(2) A, c = 6.939(13) A, beta = 90.10 degrees (1), and Z = 4. Variable temperature (300-2 K) magnetic behavior reveals the existence of ferro- and antiferromagnetic interactions in 1 and only antiferromagnetic interactions in 2. The best fitted parameters for complex 1 are J = 13.5 cm(-)(1), J' = -18.1 cm(-)(1), and g = 2.14 considering only intra-Cu(4) interactions through carboxylate and urotropine pathways. In case of complex 2, the fit of the magnetic data considering intralayer interaction through carboxylate pathway as well as interlayer interaction via urotropine pathway gave no satisfactory result at this moment using any model known due to considerable orbital contribution of Co(II) ions to the magnetic moment and its complicated structure. Assuming isolated Co(II) ions (without any coupling, J = 0) the shape of the chi(M)T curve fits well with experimental data except at very low temperatures.

Related Papers

• → Ferromagnetic coupling in the malonato-bridged copper(ii) chains [Cu(Im)₂(mal)]_nand [Cu(2-MeIm)₂(mal)]_n(H₂mal = malonic acid, Im = imidazole and 2-MeIm = 2-methylimidazole)(2002)79 cited
• → A new polynuclear Fe(III) cluster based on inorganic O-donor polyoxometalate and organic N-donor ligands(2009)20 cited
• → Six new metal(II) complexes with 3D network structures based on carboxylate and hexamethylenetetramine: Syntheses and structures(2015)13 cited
• → A photoluminescent 3D silver(I) polymer with mixed 2-naphthol-5-carboxylate and hexamethylenetetramine ligands, showing an unusual (3,4)-connected (6·7·8)2(4·6·7)2(4·7·8)2(72·8)2(62·7·83)(62·72·8·10) topology(2009)12 cited
• → Magnesium Coordination Chemistry: A Case Study of Magnesium Carboxylate Complexes with Hexamethylenetetramine(2022)2 cited