Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1979 Synthesis and structure of two octahedral molybdenum chloride sulfide clusters John Byrne Michel Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Inorganic Chemistry Commons Recommended Citation Michel, John Byrne, "Synthesis and structure of two octahedral molybdenum chloride sulfide clusters " (1979). Retrospective Theses and Dissertations. 7297. https://lib.dr.iastate.edu/rtd/7297 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 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Ml 48106 18 BEDFORD ROW, LONDON WC1R 4EJ. ENGLAND 8010248 MICHEL, JOHN BYRNE SYNTHESIS AND STRUCTURE OF TWO OCTAHEDRAL MOLYBDENUM CHLORIDE SULFIDE CLUSTERS Iowa Slate University PH.D. 1979 University Microfilms I ntornâtion3.1 300N. Zeeb Road, Ann Arbor.MI48106 18 Bedford Row, London WC1R4EJ, England Synthesis and structure of two octahedral molybdenum chloride sulfide clusters by John Byrne Michel A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Department: Chemistry Major: Inorganic Chemistry Approved: Signature was redacted for privacy. Signature was redacted for privacy. Signature was redacted for privacy. For the Graduate College Iowa State University Ames, Iowa 1979 ii TABLE OF CONTENTS Page INTRODUCTION 1 Statement of the Problem 1 Structure of the o^ Q Cluster 2 M b Xo structure of the a-molybdenum(II) 4 halides and derivatives Structure of the Chevrel phases 7 Bonding 12 Preparations and Chemistry of the Chevrel Phases 16 Chemistry of a-Molybdenum(II) Chloride 19 PART I. SYNTHESIS AND CHARACTERIZATION OF 25 (C5H5NH)3[(MOgClyS)Clg]- 3(CcHcNHTCl AND (CcHcNHig [(MOgClySiClg], TWO DERIVATIVES OF THE (MOgCl^S)3+ CLUSTER INTRODUCTION 26 EXPERIMENTAL 28 Materials 28 Syntheses 28 Preparation of (pyH),[(Mo,Cl_S)Cl^] 28 Preparation of (pyH)^[(MOgCl^S)Clg]•3pyHCl 29 Physical Measurements 30 Chemical analyses 30 Chlorine 2p photoelectron spectra 31 X-ray Structure Determinations 33 Collection and reduction of x-ray data for 33 (pyH)3[(MOgCl^S)Clg]•3pyHCl Solution and refinement of the structure 34 Collection and reduction of x-ray data for 36 (pyH)3[(MOgCl^S)Clg] Solution and refinement of the structure 36 iii Page DISCUSSION OF RESULTS 45 Syntheses 45 Physical Measurements 47 Infrared spectra 48 Chlorine 2p photoelectron spectra 50 X-ray Structure Determinations 56 PART II. SYNTHESIS AND STRUCTURE OF 71 (MOgS_6Cl_2)(NC5E5)g, A MOLECULAR CLUSTER RELATED TO THE CHEVKEL PHASES INTRODUCTION 72 EXPERIMENTAL 76 Materials 76 Syntheses 77 Preparation of (MogSgCl2)(NC5HC)g 77 Preparation of (MogScClqjfNCcHc)? 78 Preparation of (MogS-jCl) (NCgHgTg 78 X-ray Structure Determination 79 Collection and reduction of x-ray data 79 Solution and refinement of the structure 80 RESULTS AND DISCUSSION 85 Synthesis of (MOgSgClgifNCgHg)^ 85 Description of the Structure 89 SUMMARY 100 REFERENCES AND NOTES 105 ACKNOWLEDGEMENTS 110 iv LIST OF FIGURES Page A perspective view of the MOgXg cluster 3 A perspective view of the arrangement of 10 MogXg clusters in the Chevrel phases, with two of the six neighboring clusters deleted The chlorine 2p photoelectron spectra 52 of [(n-C^Hgj^N] [(MOgClgjClg], a; (C5H5NH)3 [(Mo6Cl7S)Cl6], b; (C5K5NH) 3[ (MogCl^S)CI.]• SfCgHgNHjCl, c A perspective view of the (M05CI7S)Clg^- 57 clusters (darkened atoms lie on cluster's 3-fold axis) and chloride ions (crosshatched atoms) in the unit cell of (C5H5NH)3 [(MogClyS)ClgJ•3(C5H5NH)CI A perspective view of the pyridinium 58 cations in the unit cell of (CcHcNH)3 [(Mo6Cl7S)Clg]•3(C5H5NH)C1 A labelled perspective view of the 50% 60 probability thermal ellipsoids of the (MogClyS)Clg3- cluster A perspective view of the arrangement of 73 MogXg clusters in the Chevrel phases, with two of the six neighboring clusters deleted A labelled perspective view of the 50% 90 probability thermal ellipsoids of the (MOgSgCl2)(NC^Hg)g cluster A perspective view down a pseudo 2-fold 91 axis of the (MogSgCl2)(NCgHgjg cluster showing the 50% probability thermal ellipsoids The chlorine 2t3 photoelectron spectrum 102 of (H3O)(CsHgNH)2(MOgC1^2S2)'5H20 V LIST OF TABLES Table I. Summary of crystal data, intensity collection, and structure refinement Table II. Final positional parameters for (CsHgNHigtfMOgCl^SjClgj.SfCgHgNHiCl Table Ill- Final positional parameters for (C5H5NH) (MOgCl.^S)Clg] Table IV. Final thermal parameters (xlO^) for (C5H5NH)(MOgCl^S)Clg]'3(CgHgNH)Cl Table V. Final thermal parameters for (CgHgNHigEfMOgCl^SiClg] Table VI. Low frequency infrared data (200-450 cm-1) Table VII. Chlorine 2p photoelectron data O Table VIII. Bond distances (A), nonbonded distances (A), and angles (deg) in (MoeClvSjCle^" cluster of (C5H5NH), [(MogClyS)Clg]•3(C5H5NH)CI 9 Table IX. Bond distances (A) and nonbonded distances (A) in (M05CI7S)Cl,^~ clusters of (C5H5NH)3[(MOgCl^S)Clg] Table X. Angles (deg) within the (MogCl^S)Cl,^ clusters of (C5H5NH)3[(MOgCl^S)Clg] O Table XI. Bond distances (A) in the pyridinium cations of both compounds O Table XII. Average bond distances (A) in selected MogXg cluster compounds O Table XIII. Average Mo-L bond lengths (A) and bond orders in selected (MogXg)Lg cluster compounds Table XIV. Positional parameters for (MOeSjCia)(NCjHg)^ vi Page Table XV. Thermal parameters for 84 (MOgSgCl^)(NCjHj)^ o Table XVI. Interatomic distances (A) and angles 92 (deg) in (MOgSgClgitNCgHg)^ Table XVII. Average intramolecular distances in 95 selected MOgXg cluster compounds 1 INTRODUCTION Statement of the Problem Since the initial report by Chevrel and co-workers^ of a new class of binary and ternary molybdenum chalcides MOgYg and M^MOgYg (Y=chalcide; M=metal cation), the prepara­ tions,^ ^ structures,^ and physical properties^^ of a large number of derivatives have been reported. This extensive activity was spurred on by the discovery that many of these "Chevrel phases" are superconductors. X8 The structures of all the Chevrel phases consist of interconnected Mo^Yg clusters. The Mo^Yg cluster is closely 4+ related to the MOgXg (X=halide) cluster of the a-molyb- 19 denum(II) halides. Since the MOgXg cluster exists in both a chalcide (MOgYg) and a halide (MOgXg^"*") form, halide- chalcide clusters MOgXg_^Y^ might also form stable compounds. The goal of this research project was the preparation and characterization of these halide-chalcide clusters. 2 Structure of the MOgXg Cluster An isolated Mo^Xg cluster unit, illustrated in Figure 1, consists of six molybdenum atoms bonded together forming an octahedral cluster, along with eight ligand atoms (halide or chalcide), each centered above one of the eight octa­ hedral faces. These eight atoms are termed "bridging ligands" because each bridges the three molybdenum atoms which comprise each octahedral face. From a different point of view, the eight bridging ligands define the vertices of a cube, with a molybdenum atom near the center of each face. The entire unit has idealized 0^ point group symmetry. The cluster has six coordination sites, each within bonding distance of a molybdenum atom. The sites are located outside the cube on the normals to the six faces of the cube. If these coordination sites are occupied by bridging ligands of neighboring clusters, the result is extensive bonding between clusters. This arrangement occurs in the structures of the Chevrel phases. In the structures of the a-molybdenum(II) halides and their derivatives, the cluster's coordination sites are occupied by "terminal ligands". Although each of these terminal ligands may be shared between a pair of clusters, they still block the close approach among neighboring clusters found in the Chevrel phase structure. In order to o MOLYBDENUM TERMINAL LIGAND BRIDGING LIGAND Figure 1.