New coordination polymer based on a triply bridged dicarboxylate ligand: Synthesis, structure, and magnetic proper of the adipato complex [Cu 4 (bpy) 4 (adip) 3 ](tcnoet) 2 Æ 2H 2 O {bpy = C 10 H 8 N 2 ; adip 2 = [O 2 C(CH 2 ) 4 CO 2 ] 2 ; tcnoet = [(NC) 2 CC(OEt)C(CN) 2 ]} Fatima Setifi a,c , Samia Benmansour a,b , Smail Triki a, * , Carlos J. Go ´mez-Garcı ´a b, * , Mathieu Marchivie a , Jean-Yves Salau ¨n a , Maamache Mustapha c a UMR CNRS 6521, Universite ´ de Bretagne Occidentale, BP 809, 29285 Brest Cedex, France b Instituto de Ciencia Molecular, Universidad de Valencia, 46071 Valencia, Spain c De ´ partement de Chimie, Faculte ´ des Sciences, Universite ´ Ferhat Abbas de Se ´ tif, Algeria Received 25 November 2006; received in revised form 27 February 2007; accepted 7 March 2007 Available online 15 March 2007 Paper presented in the MAGMANet-ECMM, European Conference on Molecular Magnetism. Abstract One-pot reaction of copper(II) chloride dihydrate CuCl 2 Æ 2H 2 O with 2,2 0 -bipyridyl (bpy = C 10 H 8 N 2 ) in the presence of sodium adi- pate Na 2 adip (adip 2 = [O 2 C(CH 2 ) 4 CO 2 ] 2 ) and potassium 1,1,3,3-tetracyano-2-ethoxypropenide (tcnoet = [(NC) 2 CC(OEt)C(CN) 2 ]) gives the new compound [Cu 4 (bpy) 4 (adip) 3 ](tcnoet) 2 Æ 2H 2 O (1), which was characterized by single crystal X-ray diffraction analysis. Cu(II) metal ion presents an elongated square pyramidal CuN 2 O 3 environment, with an oxygen atom in apical position and a base pl involving almost equivalent bond lengths. The structure can be described as a pseudo dinuclear species in which two Cu(b triply bridged by two unsymmetrical bridging oxygen atoms of two carboxylate groups and by an almost symmetrical OCO bidentate syn–syn bridging mode. Each Cu 2 dinuclear unit is triply bonded by aliphatic chains of the three adipate ligands to gen ladder-like infinite chain. Magnetic measurements exhibit a maximum in the v m versus T plot (at 5.0 K) which is characteristic of weak antiferromagnetic exchange interactions between the Cu(II) ions bridged by the carboxylate groups. Fit of the magnetic da priate model led to J value of 3.26(1) cm 1 (the Hamiltonian is written as H = 2JS a S b ). 2007 Elsevier B.V. All rights reserved. Keywords: Copper complexes; Polynitrile; Adipato complexes; Ladder-like structure; Magnetic properties 1. Introduction The polycarboxylate ligands present a very rich coordi- nation chemistry because of their ability to bridge metal transition ionsto generatevariousdiscretepolynuclear complexes and extended architectures with dimensionali- ties ranging from 1 to 3D arrangements [1,2]. The aroma multicarboxylate ligands, such as the benzene di- and tri- carboxylate anions have become one of the most deman ing spacers to the inorganic chemists for the syntheses o coordination polymers that have potential usefulapplica- tions as molecular magnetic materials as well as materials that mimick zeolite with host–guest behavior [2,3].The rigidity of the above di- and poly-carboxylate anions is in sharp contrastwith the good conformational freedom due to single-bonded carbon chains of saturated aliphatic 0020-1693/$ - see front matter 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ica.2007.03.005 * Corresponding authors. Tel.: +33 298 016 146; fax: +33 298 017 001 (S. Triki). E-mail address: triki@univ-brest.fr (S. Triki). www.elsevier.com/locate/ica Inorganica Chimica Acta 360 (2007) 3879–3886