Note Synthesis of Cu I polymers {Cu 8 (l 3 -SN 2 C 3 H 6 ) 4 (l-SN 2 C 3 H 6 ) 4 (g 1 -Cl) 8 } n and {Cu 6 (l 3 -SC 3 H 6 N 2 ) 2 (l-SC 3 H 6 N 2 ) 4 Cl 2 (l-Cl) 4 } n with imidazolidine-2-thione Tarlok S. Lobana a, * , Razia Sultana a , Alfonso Castineiras b , Ray J. Butcher c a Department of Chemistry, Guru Nanak Dev University, Amritsar 143005, India b Departamento de Quimica Inorganica, Facultad de Farmacia, Universidad de Santiago, 15782 Santiago, Spain c Department of Chemistry, Howard University, Washington DC 20059, USA article info Article history: Received 5 June 2009 Received in revised form 8 September 2009 Accepted 20 September 2009 Available online 24 September 2009 Keywords: Polymer Copper(I) X-ray crystallography Imidazolidine-2-thione abstract A mixture of copper(I) chloride with imidazolidine-2-thione (SC 3 H 6 N 2 ) (M:L::1:1 ratio) in acetonitrile when left undisturbed at room temperature yielded the polymer, {Cu 8 (l 3 -SN 2 C 3 H 6 ) 4 (l-SN 2 C 3 H 6 ) 4 (g 1 - Cl) 8 } n 1 (pale olive green). The same reaction in 1:2 molar ratio yielded polymer 1 along with a new poly- mer {Cu 6 (l 3 -SC 3 H 6 N 2 ) 2 (l-SC 3 H 6 N 2 ) 4 Cl 2 (l-Cl) 4 } n 2 (colorless). Polymers 1 and 2 have been characterized using elemental analysis, infrared spectroscopy and single crystal X-ray crystallography. The central core of polymer 1 forms staircase like polymeric chains running diagonally in the ab plane. The closest CuÁÁÁCu contact in Cu 2 S 2 core is 2.8327(7) Å. The step-like tetranuclear Cu 4 S 2 Cl 2 core of 2 has CuÁÁÁCu contact of 2.7974(4) Å in hetero-bridged Cu(l-Cl)(l-S)Cu moiety, and this contact is 2.7553(7) Å in homo-bridged Cu(l-S) 2 Cu moiety. Ó 2009 Elsevier B.V. All rights reserved. 1. Introduction Coordination polymers form an important component of re- search of inorganic chemists for developing new functional mate- rials, in view of their possible applications in molecular recognition [1,2], optics [3,4], semiconductors [5], thermal proper- ties [6,7], photoluminescent [8,9], electrical conductivity [10], photoconductivity [11], crystal engineering [12,13], supramolecu- lar chemistry [14–21], ion exchange [22], and gas storage [23]. Re- cently, it has been reported that simplest heterocyclic thioamides such as pyridine-2-thione (I, SC 5 H 4 NH), imidazolidine-2-thione (II, SC 3 H 6 N 2 ), and 1-methyl-imidazoline-2-thione (III, SC 4 H 6 N 2 ) (Chart 1) have shown propensity to form polymeric complexes, namely, {Cu 6 (l 3 -SC 5 H 4 NH) 4 (l 2 -SC 5 H 4 NH) 2 (I 4 )(l-I) 2 -} n Á2nCH 3 CN, {Cu 6 (l 3 -SC 3 H 6 N 2 ) 2 (l 2 -SC 3 H 6 N 2 ) 4 X 2 (l-X) 4 } n (X = Br, I), {Cu 6 (l 3 -SC 3 H 6 N 2 ) 4 (l-SC 3 H 6 N 2 ) 2 (l-I) 2 I 4 } n , {Cu 2 (l-SC 3 H 6 N 2 ) 2 (l-SCN) 2 } n [24,25] {Cu 2 (l-I) 2 (l-SC 4 H 6 N 2 ) 2 } n [26]. The formation of these polymers in- volves variable coordination ability of sulfur and participation of halogen/pseudo donor atoms in chain formation. In literature, copper(I) chloride with imidazolidine-2-thione has formed an unsymmetrical dimer, [(Cl)(g 1 -SC 3 H 6 N 2 )Cu(l-SC 3 H 6 N 2 ) Cu(g 1 -SC 3 H 6 N 2 ) 2 Cl] [25], and change of experimental conditions has yielded, two new Cu I polymers, {Cu 8 (l 3 -SN 2 C 3 H 6 ) 4 (l-SN 2 C 3 - H 6 ) 4 (g 1 -Cl) 8 } n 1 and {Cu 6 (l 3 -SC 3 H 6 N 2 ) 2 (l 2 -SC 3 H 6 N 2 ) 4 Cl 2 (l-Cl) 4 } n 2, which are described in this paper. These are obtained from reac- tions of copper(I) chloride with imidazolidine-2-thione in acetoni- trile under mild experimental conditions and have been characterized using analytical data, spectroscopy and single crystal X-ray crystallography. 2. Experimental 2.1. Chemical reagents Copper(I) chloride was prepared by reducing an aqueous solu- tion of CuSO 4 Á5H 2 O using SO 2 in the presence of NaCl in water [27]. The ligand imidazolidine-2-thione was procured from Aldrich Chemicals Ltd. and used as such. 2.2. Measurements C, H and N analysis were obtained with Thermoelectron FLAS- HEA1112 CHNS analyzer. The IR spectra were recorded using KBr pellets in the range 4000–200 cm À1 on Pye-Unicam SP-3-300 spec- trophotometer. The melting points were determined with a Gal- lenkamp electrically heated apparatus. 2.3. Synthesis of compounds 2.3.1. {Cu 8 (l 3 -SC 3 H 6 N 2 ) 4 (l-SC 3 H 6 N 2 ) 4 (g 1 -Cl) 8 } n 1 To a solution of copper(I) chloride (0.025 g, 0.24 mmol) in acetonitrile was added a solution of imidazolidine-2-thione 0020-1693/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.ica.2009.09.038 * Corresponding author. Fax: +91 183 2258820. E-mail address: tarlokslobana@yahoo.co.in (T.S. Lobana). Inorganica Chimica Acta 362 (2009) 5265–5270 Contents lists available at ScienceDirect Inorganica Chimica Acta journal homepage: www.elsevier.com/locate/ica