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Title: Phase polymorphism of novel [Ru(NH{sub 3}){sub 6}](ClO{sub 4}){sub 3}—Comparison with [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part II

[Ru(NH{sub 3}){sub 6}](ClO{sub 4}){sub 3} undergoes two phase transitions at: T{sub C1}=290.3 K and T{sub C2}=74.8 K , thus exhibits three crystalline phases in the temperature range of 5–310 K. For the detected phase transitions, thermal effects were determined. Fourier transform far- and middle-infrared spectra (FT-FIR and FT-MIR), recorded at 8–350 K, suggest that reorientational motions of the NH{sub 3} ligands are very fast (τ{sub R}≈10{sup −12} s above T{sub C1}) and are significantly slowed down below T{sub C2}. X-ray single crystal diffraction (XRSCD) measurements revealed that in the high temperature phase (above T{sub C1}) the compound belongs to the cubic Fm3{sup ¯}m (No. 225) space group, whereas in the intermediate phase the unit cell parameter doubles and the space group is Ia3{sup ¯}(No. 206). {sup 1}H NMR studies revealed that the following reorientational motions are liberated during heating: three-fold reorientation of NH{sub 3} ligands, three-fold reorientation of the entire [Ru(NH{sub 3}){sub 6}]{sup 3+} cation, and isotropic reorientation of this cation. In the high temperature phase I the cations perform isotropic reorientations with the estimated activation energy equal to ca. 30.1 kJ mol{sup −1}. Comparison with adequate results obtained earlier for [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} and for other similarmore » compounds was made and general regularities were drawn. - Graphical abstract: Molar heat capacities obtained for [Ru(NH{sub 3}){sub 6}](ClO{sub 4}){sub 3} at temperatures between 5 and 310 K. Molecular structure of [Ru(NH{sub 3}){sub 6}]{sup 3+} and two types of ClO{sub 4}{sup -} varying in dynamic disorder at 293 K. Highlights: • Two solid phase transitions have been found in [Ru(NH{sub 3}){sub 6}](ClO{sub 4}){sub 3}. • The transitions are triggered by the hydrogen bond interactions between NH{sub 3} ligands and ClO{sub 4}{sup −} anions. • The complex is a highly dynamically disordered crystal across a wide temperature range.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [1]
  1. Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków (Poland)
  2. Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, 560-0043 Osaka (Japan)
  3. Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)
Publication Date:
OSTI Identifier:
22274044
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 204; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACTIVATION ENERGY; AMMONIA; ANIONS; CALORIMETRY; CATIONS; CUBIC LATTICES; FOURIER TRANSFORMATION; HYDROGEN; INFRARED SPECTRA; LIGANDS; MOLECULAR DYNAMICS METHOD; MOLECULAR STRUCTURE; MONOCRYSTALS; NUCLEAR MAGNETIC RESONANCE; PERCHLORATES; PHASE TRANSFORMATIONS; SPACE GROUPS; SPECIFIC HEAT; X-RAY DIFFRACTION