Poster Presentations

[MS39-P04] Synthesis and crystal structure be very interesting from catalysis point of view of Fe Ca (SeO ) Cl - a porous oxohalide. if guest molecules could be introduced into the 6 2 1 3 9 4 1 Shichao Hu , Mats Johnsson channel system that contains rich transition metals as active sites during catalysis reactions. 1 Department of Materials and Environmental Unfortunately, these channels are not accessible Chemistry, Stockholm University, Sweden to guest species because most part of E-mail: [email protected] the non-bonding region is occupied by lone- pair electrons and halogen ions, the rest free space has only 3 ~ 4 Å left in diameter. The Transition metal oxohalide compounds present study was carried out to utilize alkaline containing p-block elements in low oxidation earth metal as extra building unit in structure states carrying a stereochemically active construction. Herein, a porous oxohalide, lone-pair have proved to be a group rich in Fe Ca (SeO ) Cl , has been synthesized by 6 2 3 9 4 unusual crystal structures. Examples of lone-pair chemical vapour transport reactions using conc. 4+ 4+ 4+ 4+ elements are Se , Te , Sb , Bi , etc., that HCl as Cl-source and transporting agent. It adopt an asymmetric or one-sided coordination crystallizes in the hexagonal space group P63/m due to the presence of a stereochemically with unit cell parameters a = 12.118(2) Å, 3+ active electron lone-pair which do not participate c = 12.703(4) Å, Z = 2. The Fe ions have in bonding but occupies a volume similar to octahedral [FeO ] and more uncommon 6 2+ [FeO Cl ] coordination’s, the Ca ions that of an oxygen [1-2] that result in voids in 4 2 4+ the crystal structure. The lone pair cations are coordinate an [CaO6] octahedron, the Se ions found to most often form bonds only to oxygen in show classic one-sided [SeO ] coordination. The 3 oxohalide due to their high Lewis acid strength crystal structure is an open framework having and small radius while the transition metal one dimensional channels extending along [001] 4+ cations bond to both oxygen and halides. As a that the chlorine atoms and lone pairs on Se are result, the combination of stereochemically facing. The channels in this framework structure active lone pair and the halide ions which often are unusually large compared to other oxohalide have low coordination number can act as compounds and also accessible to guest “chemical scissors” to open up the structures and molecules. Water vapor sorption measurements increase the possibilities for low-dimensional show an uptake of 9 wt% at 293 K. arrangements of transition metals. By utilizing this concept, a number compounds with unusual [1] Orgel, L. E. J. Chem. Soc. 1959, low-dimensional crystal structures have been 4, 3815−3819. synthesized, which may even show interesting [2] Seshadri, R.; Hill, N. A. Chem. Mater. physical properties such as magnetic frustration 2001, 13, 2892−2899. [3] or nonlinear optical second harmonic [3] R. Becker, M. Johnsson, R. K. Kremer, generation (SHG) [4]. There are mainly two H-H. Klauss, and P. Lemmens, J. Am. Chem. types of structures among M-L-O-X compounds Soc. 128 (2006) 15469-15475. (M = transition metal cation, L = p-block lone 4+ 4+ 3+ [4] S.-H. Kim, J. Yeon and P.S. Halasyamani, pair element such as Se , Te , or Sb , X = halide Chem. Mater., 2009, 21, 5335-5342. anion). One of them is often layered with only weak van der Waals interactions in between the Keywords: Lone-pair elements; Porous layers. Another type exhibits 3D open framework materials; Oxo-halides having channels or voids where lone- pairs and halides are located and shows similar structural feature as the well-known porous materials such as zeolites. Therefore, it would

28th European Crystallographic Meeting, ECM 28, UK, 2013 Acta Cryst. (2013). A69, s657 Page s657