Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties

We are reporting two new mixed valent Co(ii)/Co(iii) polynuclear complexes, {Co II 6 Co III 3 } and {Co II Co III 4 }, bearing different amount of Co(ii) ions in their cores, through the employment of the multidentate triethanolamine (teaH 3 ) ligand in different stoichiometric ratios. We present a...

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Autores principales: Funes, A.V., Carrella, L., Sorace, L., Rentschler, E., Alborés, P.
Formato: JOUR
Materias:
Ground state
Magnetic relaxation measurement
Magnetism
Magnetization
Magnetization reversal
Temperature distribution
Characteristic relaxation time
External magnetic field
Magnetostructural correlations
Mixed-valent complexes
Orbital contribution
Polynuclear complexes
Temperature dependence
Zero-field splitting parameters
Cobalt compounds
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_14779226_v44_n5_p2390_Funes
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_14779226_v44_n5_p2390_Funes2023-10-03T16:19:16Z Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties Funes, A.V. Carrella, L. Sorace, L. Rentschler, E. Alborés, P. Ground state Magnetic relaxation measurement Magnetism Magnetization Magnetization reversal Temperature distribution Characteristic relaxation time External magnetic field Magnetostructural correlations Mixed-valent complexes Orbital contribution Polynuclear complexes Temperature dependence Zero-field splitting parameters Cobalt compounds We are reporting two new mixed valent Co(ii)/Co(iii) polynuclear complexes, {Co II 6 Co III 3 } and {Co II Co III 4 }, bearing different amount of Co(ii) ions in their cores, through the employment of the multidentate triethanolamine (teaH 3 ) ligand in different stoichiometric ratios. We present a complete picture of the magnetic behaviour of both complexes through a combined usage of the susceptibility, magnetization and X-band EPR data as well as broken-symmetry DFT calculations. Compound 1 shows an atypical spin-only behaviour, probably due to the presence of four and five coordinated Co(ii) sites as well as highly distorted six coordinated Co(ii) ions, promoting a high degree of orbital contribution quenching. Through the usage of a simplified exchange coupling scheme and relying on DFT based magneto-structural correlation we have been able to explain the observed diamagnetic ground state. Concerning compound 2, DC magnetic data supported by X-band EPR measurements suggest the existence of anisotropy with a zero-field splitting parameter D, at least in the range of 2-10 cm -1 . In agreement with this description, a slow relaxation of magnetization is observed after applying a small external magnetic field, under AC measurements. Field and temperature dependence of the characteristic relaxation time establishes a thermal barrier for magnetization reversal of about 25 cm -1 , which is in good agreement with the energy splitting of the |±1/2〉 and |±3/2〉 doublets established from static magnetic measurements. © The Royal Society of Chemistry 2015. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14779226_v44_n5_p2390_Funes
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Ground state
Magnetic relaxation measurement
Magnetism
Magnetization
Magnetization reversal
Temperature distribution
Characteristic relaxation time
External magnetic field
Magnetostructural correlations
Mixed-valent complexes
Orbital contribution
Polynuclear complexes
Temperature dependence
Zero-field splitting parameters
Cobalt compounds
spellingShingle Ground state
Magnetic relaxation measurement
Magnetism
Magnetization
Magnetization reversal
Temperature distribution
Characteristic relaxation time
External magnetic field
Magnetostructural correlations
Mixed-valent complexes
Orbital contribution
Polynuclear complexes
Temperature dependence
Zero-field splitting parameters
Cobalt compounds
Funes, A.V.
Carrella, L.
Sorace, L.
Rentschler, E.
Alborés, P.
Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
topic_facet Ground state
Magnetic relaxation measurement
Magnetism
Magnetization
Magnetization reversal
Temperature distribution
Characteristic relaxation time
External magnetic field
Magnetostructural correlations
Mixed-valent complexes
Orbital contribution
Polynuclear complexes
Temperature dependence
Zero-field splitting parameters
Cobalt compounds
description We are reporting two new mixed valent Co(ii)/Co(iii) polynuclear complexes, {Co II 6 Co III 3 } and {Co II Co III 4 }, bearing different amount of Co(ii) ions in their cores, through the employment of the multidentate triethanolamine (teaH 3 ) ligand in different stoichiometric ratios. We present a complete picture of the magnetic behaviour of both complexes through a combined usage of the susceptibility, magnetization and X-band EPR data as well as broken-symmetry DFT calculations. Compound 1 shows an atypical spin-only behaviour, probably due to the presence of four and five coordinated Co(ii) sites as well as highly distorted six coordinated Co(ii) ions, promoting a high degree of orbital contribution quenching. Through the usage of a simplified exchange coupling scheme and relying on DFT based magneto-structural correlation we have been able to explain the observed diamagnetic ground state. Concerning compound 2, DC magnetic data supported by X-band EPR measurements suggest the existence of anisotropy with a zero-field splitting parameter D, at least in the range of 2-10 cm -1 . In agreement with this description, a slow relaxation of magnetization is observed after applying a small external magnetic field, under AC measurements. Field and temperature dependence of the characteristic relaxation time establishes a thermal barrier for magnetization reversal of about 25 cm -1 , which is in good agreement with the energy splitting of the |±1/2〉 and |±3/2〉 doublets established from static magnetic measurements. © The Royal Society of Chemistry 2015.
format JOUR
author Funes, A.V.
Carrella, L.
Sorace, L.
Rentschler, E.
Alborés, P.
author_facet Funes, A.V.
Carrella, L.
Sorace, L.
Rentschler, E.
Alborés, P.
author_sort Funes, A.V.
title Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
title_short Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
title_full Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
title_fullStr Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
title_full_unstemmed Switching nuclearity and Co(II) content through stoichiometry adjustment: {Co II 6 Co III 3 } and {Co II Co 4 III } mixed valent complexes and a study of their magnetic properties
title_sort switching nuclearity and co(ii) content through stoichiometry adjustment: {co ii 6 co iii 3 } and {co ii co 4 iii } mixed valent complexes and a study of their magnetic properties
url http://hdl.handle.net/20.500.12110/paper_14779226_v44_n5_p2390_Funes
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