Preparation and structures of copper(II) and zinc(II) complexes with 5-ferrocenylpyrimidine: Structural variation derived from flexible coordination ability of the ligand and metal ions Ryo Horikoshi, Kazuya Okazawa, Tomoyuki Mochida * Department of Chemistry, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan Received 21 December 2004; accepted 1 February 2005 Available online 11 March 2005 Abstract 5-Ferrocenylpyrimidine (FcPM) reacts with dinuclear copper(II) carboxylates ([Cu 2 (RCOO) 4 ]; R = C 6 H 5 ,C 5 H 11 , CH 3 ) to produce one-dimensional coordination polymers [Cu 2 (C 6 H 5 COO) 4 (FcPM)] n (1), [Cu 2 (C 5 H 11 COO) 4 (FcPM)] n Æ nCH 3 CN (2), and a discrete tetranuclear complex [Cu 2 (CH 3 COO) 4 (FcPM) 2 ](3). Compounds 1 and 2 show similar zigzag chain structures, comprising alternate linking of FcPM and dinuclear copper(II) units, whereas the structure of 3 corresponds to the local structural motifs of 1 and 2. Reaction of FcPM with zinc salts (ZnX 2 ; X = NO 3 , SCN) affords zinc-centered ferrocenyl cluster complexes, [Zn(NO 3 ) 2 (FcPM) 3 ](4) and [Zn(SCN) 2 (FcPM) 2 ] Æ 0.5H 2 O(5), with varying M:L ratios. FcPM acts as a bidentate ligand in 1 and 2, and as a monodentate ligand in the others. Ó 2005 Elsevier B.V. All rights reserved. Keywords: Coordination polymer; Polynuclear complex; Ferrocene derivative; Copper carboxylate; Zinc 1. Introduction The designed construction of supramolecular coordi- nation compounds, as prepared by the spontaneous self- assembly of metal ions and functional ligands, has received much attention in recent years [1]. In particular, construction of mixed-metal supramolecular assemblies is an important theme in modern chemistry [2]. We de- signed several ferrocene-based ligands and combined them with appropriate metal ions to construct mixed- metal supramolecular complexes [3]. Synthesis of ferro- cene-based ligands and their molecular complexes has been studied for many years, but most of those studies use ferrocenyl-substituted carboxylates [4] and 1,1 0 - disubstituted ferrocenes such as 1,1 0 -bis(diphenyl- phosphino)ferrocene (dppf) [5], and the number of mono-substituted heteroaryl ferrocenes is small [6]. Therefore, we have designed a heteroaryl-substituted ferrocene, 5-ferrocenylpyrimidine (FcPM, Chart 1) [3d], which has proven to be a highly versatile molecule for supramolecular construction. Acting as a bridging or a monodentate ligand, FcPM can produce polynuclear complexes [3c] and coordination polymers [3d]. It can even act as a hydrogen bonding acceptor to form hydro- gen-bonded supramolecular assemblies [7]. This struc- tural variety contrasts with the rather simpler complexation modes exhibited by 1,1 0 -disubstituted ferrocenes with heteroaryl rings such as 1,1 0 -di(4-pyr- idyl)ferrocene (Fc(4-py) 2 ) [8] and 1,1 0 -di(pyrazinyl)ferro- cene (Fc(pyz) 2 ), which tend to produce tetranuclear metalla-macrocycles. Appropriate choice of metal ions is a crucial factor in the directed synthesis of metal assemblies. So far, we have prepared coordination compounds of FcPM with several metal salts, MX 2 (M = Ni II , Co II , Cu II ; 0022-328X/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jorganchem.2005.02.003 * Corresponding author. Tel./fax: +81 474724406. E-mail address: mochida@chem.sci.toho-u.ac.jp (T. Mochida). Journal of Organometallic Chemistry 690 (2005) 1793–1799 www.elsevier.com/locate/jorganchem