A room temperature structure for anhydrous lead (II) decanoate Henry A. Ellis a, * , Nicole A. White a , Ishmael Hassan a , Rafi Ahmad b a Department of Chemistry, University of The West Indies, Mona, Kingston 7, Jamaica b Department of Geology, University of The West Indies, Kingston 7, Jamaica Received 8 May 2002; revised 19 July 2002; accepted 19 July 2002 Abstract The room temperature structure of anhydrous lead (II) decanoate has been studied using X-ray diffraction, infrared spectroscopy and polarizing light microscopy. A triclinic unit cell with dimensions: a ¼ 8.529 (3), b ¼ 11.207 (4), c ¼ 28.451 (2) A ˚ ; a ¼ 83.814 (2), b ¼ 88.971 (2), g ¼ 65.143 (3); Z ¼ 4, M ¼ 549.2 g mol 21 , D c ¼ 1.50 (6), D m ¼ 1.68 (2) is indicated. Infrared and powder diffraction data point to a structure containing both bidentate bonding and carboxylate bridging around, possibly eight coordinated lead. A bilayer arrangement of chains at an average 688 to planes containing Pb 2þ ions is proposed. Each molecule is situated at the corners and center of the unit cell with possibly P  1 symmetry as is the case for copper (II) decanoate. q 2002 Published by Elsevier Science B.V. Keywords: Lead (II) decanoate; X-ray diffraction; IR spectroscopy; Polarizing light microscopy 1. Introduction Anhydrous lead (II) decanoate, (CH 3 (CH 2 ) 8- COO) 2 Pb, exhibits two thermotropic phases between the solid and isotropic liquid [1–3]. Whilst the two phases have been studied extensively and their likely structures reported [2–4], very little previous work has been reported on the type of bonding present and molecular structure of the room temperature solid. The available data, collected from X-ray diffraction studies, model calculations [4,5] and NMR spec- troscopy [3], support a lamellar structure. Within the lamellae the hydrocarbon chains are reported to be in the all-trans, fully extended configuration, orthogonal [6,7] or tilted [4,5] to planes containing Pb 2þ ions. Because of low crystal symmetry of the compound, it is difficult to prepare single crystals for X-ray analysis. Nevertheless, useful structural information can be obtained from a variety of other physical methods. Accordingly, X-ray diffraction, infrared spec- troscopy (IR) and polarizing light microscopy are used to investigate the room temperature molecular structure of the white para-crystalline solid. 2. Experimental Lead (II) decanoate was prepared as described earlier [8,9], purified by repeated crystallizations from toluene, vacuum dried and its purity checked by elemental analysis: (Found: C, 43.72; H, 7.01; Pb, 0022-2860/02/$ - see front matter q 2002 Published by Elsevier Science B.V. PII: S0022-2860(02)00386-1 Journal of Molecular Structure 642 (2002) 71–76 www.elsevier.com/locate/molstruc * Corresponding author. Tel.: þ876-927-1910; fax: þ 876-977- 1835. E-mail address: haellis@uwimona.edu.jm (H.A. Ellis).