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Title: Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I

Abstract

Four crystalline phases of the coordination compound [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} are identified by adiabatic calorimetry. Three phase transitions, one at T{sub C3}(IV{yields}III)=30.7 K, the second at T{sub C2}(III{yields}II)=91.7 K (both accompanied by comparable entropy changes 3.0 and 3.1 J K{sup -1} mol{sup -1}, respectively) and the third at T{sub C1}(II{yields}I)=241.6 K (accompanied by an entropy change of 8.1 J K{sup -1} mol{sup -1}) were discovered. X-ray single crystal diffraction (at 293 K) demonstrates that phase I is a highly dynamic disordered cubic phase (Fm3{sup Macron }m, No. 225) with two types of BF{sub 4}{sup -} anions differing in a degree of disorder. In phase II (at 170 K) the structure remains cubic (Ia3{sup Macron }, No. 206), with two different types of cations and four different types of anions. Splitting of certain IR bands connected with NH{sub 3} ligands at the observed phase transitions suggests a lowering of the symmetry of the [Ru(NH{sub 3}){sub 6}]{sup 3+} complex cation. Both NH{sub 3} ligands and BF{sub 4}{sup -} anions perform fast reorientations ({tau}{sub R} Almost-Equal-To 10{sup -12} s), which are significantly slowed down below the phase transition at T{sub C3}. {sup 1}H NMR studies led to estimate the values ofmore » the activation energy of NH{sub 3} ligands reorientation in the phases II and I as equal to {approx}8 kJ mol{sup -1}. In phase I the whole hexammineruthenium(III) cations reorientation as a tumbling process can be noticed. The activation energy value of this motion is {approx}24 kJ mol{sup -1}. {sup 19}F NMR studies give the values of the activation energy of BF{sub 4}{sup -} anions reorientation as {approx}6 kJ mol{sup -1}. Above the phase transition temperature half of BF{sub 4}{sup -} anions perform a tumbling motion with E{sub a} Almost-Equal-To 8 kJ mol{sup -1}. - Graphical abstract: A series of complementary methods, such as Adiabatic Calorimetry, Differential Scanning Calorimetry, Fourier Transform-Far and Middle Spectroscopy, proton and fluorine Nuclear Magnetic Resonance and structural methods reveal information about phase transitions in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Highlights: Black-Right-Pointing-Pointer Three novel phase transitions are found in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Black-Right-Pointing-Pointer The thermodynamic parameters of the phase transitions are derived. Black-Right-Pointing-Pointer The transitions are of order-disorder type. Black-Right-Pointing-Pointer The complex belongs to Fm3{sup Macron }m at 293 K and its symmetry changes to Ia3{sup Macron} at 170 K. Black-Right-Pointing-Pointer [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} is a highly dynamically disordered crystal.« less

Authors:
 [1];  [1];  [2];  [2];  [3];  [1]
  1. Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland)
  2. Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
  3. Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznan 61-614 (Poland)
Publication Date:
OSTI Identifier:
22131209
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 197; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; AMMONIA; ANIONS; CALORIMETRY; CATIONS; ENTROPY; FLUOROBORATES; FOURIER TRANSFORMATION; MONOCRYSTALS; NUCLEAR MAGNETIC RESONANCE; PHASE TRANSFORMATIONS; SPECTROSCOPY; TRANSITION TEMPERATURE; X-RAY DIFFRACTION

Citation Formats

Dolega, Diana, Mikuli, Edward, Inaba, Akira, Gorska, Natalia, Holderna-Natkaniec, Krystyna, and Nitek, Wojciech. Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I. United States: N. p., 2013. Web. doi:10.1016/J.JSSC.2012.08.048.
Dolega, Diana, Mikuli, Edward, Inaba, Akira, Gorska, Natalia, Holderna-Natkaniec, Krystyna, & Nitek, Wojciech. Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I. United States. doi:10.1016/J.JSSC.2012.08.048.
Dolega, Diana, Mikuli, Edward, Inaba, Akira, Gorska, Natalia, Holderna-Natkaniec, Krystyna, and Nitek, Wojciech. Tue . "Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I". United States. doi:10.1016/J.JSSC.2012.08.048.
@article{osti_22131209,
title = {Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I},
author = {Dolega, Diana and Mikuli, Edward and Inaba, Akira and Gorska, Natalia and Holderna-Natkaniec, Krystyna and Nitek, Wojciech},
abstractNote = {Four crystalline phases of the coordination compound [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} are identified by adiabatic calorimetry. Three phase transitions, one at T{sub C3}(IV{yields}III)=30.7 K, the second at T{sub C2}(III{yields}II)=91.7 K (both accompanied by comparable entropy changes 3.0 and 3.1 J K{sup -1} mol{sup -1}, respectively) and the third at T{sub C1}(II{yields}I)=241.6 K (accompanied by an entropy change of 8.1 J K{sup -1} mol{sup -1}) were discovered. X-ray single crystal diffraction (at 293 K) demonstrates that phase I is a highly dynamic disordered cubic phase (Fm3{sup Macron }m, No. 225) with two types of BF{sub 4}{sup -} anions differing in a degree of disorder. In phase II (at 170 K) the structure remains cubic (Ia3{sup Macron }, No. 206), with two different types of cations and four different types of anions. Splitting of certain IR bands connected with NH{sub 3} ligands at the observed phase transitions suggests a lowering of the symmetry of the [Ru(NH{sub 3}){sub 6}]{sup 3+} complex cation. Both NH{sub 3} ligands and BF{sub 4}{sup -} anions perform fast reorientations ({tau}{sub R} Almost-Equal-To 10{sup -12} s), which are significantly slowed down below the phase transition at T{sub C3}. {sup 1}H NMR studies led to estimate the values of the activation energy of NH{sub 3} ligands reorientation in the phases II and I as equal to {approx}8 kJ mol{sup -1}. In phase I the whole hexammineruthenium(III) cations reorientation as a tumbling process can be noticed. The activation energy value of this motion is {approx}24 kJ mol{sup -1}. {sup 19}F NMR studies give the values of the activation energy of BF{sub 4}{sup -} anions reorientation as {approx}6 kJ mol{sup -1}. Above the phase transition temperature half of BF{sub 4}{sup -} anions perform a tumbling motion with E{sub a} Almost-Equal-To 8 kJ mol{sup -1}. - Graphical abstract: A series of complementary methods, such as Adiabatic Calorimetry, Differential Scanning Calorimetry, Fourier Transform-Far and Middle Spectroscopy, proton and fluorine Nuclear Magnetic Resonance and structural methods reveal information about phase transitions in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Highlights: Black-Right-Pointing-Pointer Three novel phase transitions are found in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Black-Right-Pointing-Pointer The thermodynamic parameters of the phase transitions are derived. Black-Right-Pointing-Pointer The transitions are of order-disorder type. Black-Right-Pointing-Pointer The complex belongs to Fm3{sup Macron }m at 293 K and its symmetry changes to Ia3{sup Macron} at 170 K. Black-Right-Pointing-Pointer [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} is a highly dynamically disordered crystal.},
doi = {10.1016/J.JSSC.2012.08.048},
journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = ,
volume = 197,
place = {United States},
year = {2013},
month = {1}
}