Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes

Autores
Cáceres Vázquez, Joaquín; Jara, Danilo H.; Costamagna, Juan; Martínez Gómez, Fabián; Silva, Carlos; Lemus, Luis; Freire Espeleta, Eleonora; Baggio, Ricardo Fortunato; Vera, Cristian; Guerrero, Juan
Año de publicación
2022
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular π stacking and hydrogen bonding. 1H-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-1H-NMR experiments for several concentrations at different temperatures. The values for KD (4.0 to 70.0 M−1 range), ΔH (−1.4 to −2.6 kcal mol−1 range), ΔS (−0.2 to 2.1 cal mol−1 K−1 range), and ΔG298 (−0.8 to −2.0 kcal mol−1 range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative equilibria.
Fil: Cáceres Vázquez, Joaquín. Universidad de Santiago de Chile; Chile
Fil: Jara, Danilo H.. Universidad Adolfo Ibañez; Chile
Fil: Costamagna, Juan. Universidad de Santiago de Chile; Chile
Fil: Martínez Gómez, Fabián. Universidad de Santiago de Chile; Chile
Fil: Silva, Carlos. Universidad de Santiago de Chile; Chile
Fil: Lemus, Luis. Universidad de Santiago de Chile; Chile
Fil: Freire Espeleta, Eleonora. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Baggio, Ricardo Fortunato. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina
Fil: Vera, Cristian. Universidad de Santiago de Chile; Chile
Fil: Guerrero, Juan. Universidad de Santiago de Chile; Chile
Materia
Cu complexes
Cristal structure
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/202670

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oai_identifier_str oai:ri.conicet.gov.ar:11336/202670
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repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexesCáceres Vázquez, JoaquínJara, Danilo H.Costamagna, JuanMartínez Gómez, FabiánSilva, CarlosLemus, LuisFreire Espeleta, EleonoraBaggio, Ricardo FortunatoVera, CristianGuerrero, JuanCu complexesCristal structurehttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular π stacking and hydrogen bonding. 1H-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-1H-NMR experiments for several concentrations at different temperatures. The values for KD (4.0 to 70.0 M−1 range), ΔH (−1.4 to −2.6 kcal mol−1 range), ΔS (−0.2 to 2.1 cal mol−1 K−1 range), and ΔG298 (−0.8 to −2.0 kcal mol−1 range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative equilibria.Fil: Cáceres Vázquez, Joaquín. Universidad de Santiago de Chile; ChileFil: Jara, Danilo H.. Universidad Adolfo Ibañez; ChileFil: Costamagna, Juan. Universidad de Santiago de Chile; ChileFil: Martínez Gómez, Fabián. Universidad de Santiago de Chile; ChileFil: Silva, Carlos. Universidad de Santiago de Chile; ChileFil: Lemus, Luis. Universidad de Santiago de Chile; ChileFil: Freire Espeleta, Eleonora. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baggio, Ricardo Fortunato. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Vera, Cristian. Universidad de Santiago de Chile; ChileFil: Guerrero, Juan. Universidad de Santiago de Chile; ChileRoyal Society of Chemistry2022-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/202670Cáceres Vázquez, Joaquín; Jara, Danilo H.; Costamagna, Juan; Martínez Gómez, Fabián; Silva, Carlos; et al.; Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes; Royal Society of Chemistry; RSC Advances; 13; 2; 12-2022; 825-8382046-2069CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1039/d2ra05341ainfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:47:45Zoai:ri.conicet.gov.ar:11336/202670instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:47:46.043CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
title Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
spellingShingle Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
Cáceres Vázquez, Joaquín
Cu complexes
Cristal structure
title_short Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
title_full Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
title_fullStr Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
title_full_unstemmed Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
title_sort Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes
dc.creator.none.fl_str_mv Cáceres Vázquez, Joaquín
Jara, Danilo H.
Costamagna, Juan
Martínez Gómez, Fabián
Silva, Carlos
Lemus, Luis
Freire Espeleta, Eleonora
Baggio, Ricardo Fortunato
Vera, Cristian
Guerrero, Juan
author Cáceres Vázquez, Joaquín
author_facet Cáceres Vázquez, Joaquín
Jara, Danilo H.
Costamagna, Juan
Martínez Gómez, Fabián
Silva, Carlos
Lemus, Luis
Freire Espeleta, Eleonora
Baggio, Ricardo Fortunato
Vera, Cristian
Guerrero, Juan
author_role author
author2 Jara, Danilo H.
Costamagna, Juan
Martínez Gómez, Fabián
Silva, Carlos
Lemus, Luis
Freire Espeleta, Eleonora
Baggio, Ricardo Fortunato
Vera, Cristian
Guerrero, Juan
author2_role author
author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Cu complexes
Cristal structure
topic Cu complexes
Cristal structure
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular π stacking and hydrogen bonding. 1H-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-1H-NMR experiments for several concentrations at different temperatures. The values for KD (4.0 to 70.0 M−1 range), ΔH (−1.4 to −2.6 kcal mol−1 range), ΔS (−0.2 to 2.1 cal mol−1 K−1 range), and ΔG298 (−0.8 to −2.0 kcal mol−1 range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative equilibria.
Fil: Cáceres Vázquez, Joaquín. Universidad de Santiago de Chile; Chile
Fil: Jara, Danilo H.. Universidad Adolfo Ibañez; Chile
Fil: Costamagna, Juan. Universidad de Santiago de Chile; Chile
Fil: Martínez Gómez, Fabián. Universidad de Santiago de Chile; Chile
Fil: Silva, Carlos. Universidad de Santiago de Chile; Chile
Fil: Lemus, Luis. Universidad de Santiago de Chile; Chile
Fil: Freire Espeleta, Eleonora. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Baggio, Ricardo Fortunato. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina
Fil: Vera, Cristian. Universidad de Santiago de Chile; Chile
Fil: Guerrero, Juan. Universidad de Santiago de Chile; Chile
description A series of six new Cu(i) complexes with ([Cu(N-{4-R}pyridine-2-yl-methanimine)(PPh3)Br]) formulation, where R corresponds to a donor or acceptor p-substituent, have been synthesized and were used to study self-association effects on their structural and electrochemical properties. X-ray diffraction results showed that in all complexes the packing is organized from a dimer generated by supramolecular π stacking and hydrogen bonding. 1H-NMR experiments at several concentrations showed that all complexes undergo a fast-self-association monomer-dimer equilibrium in solution, while changes in resonance frequency towards the high or low field in specific protons of the imine ligand allow establishing that dimers have similar structures to those found in the crystal. The thermodynamic parameters for this self-association process were calculated from dimerization constants determined by VT-1H-NMR experiments for several concentrations at different temperatures. The values for KD (4.0 to 70.0 M−1 range), ΔH (−1.4 to −2.6 kcal mol−1 range), ΔS (−0.2 to 2.1 cal mol−1 K−1 range), and ΔG298 (−0.8 to −2.0 kcal mol−1 range) are of the same order and indicate that the self-dimerization process is enthalpically driven for all complexes. The electrochemical profile of the complexes shows two redox Cu(ii)/Cu(i) processes whose relative intensities are sensitive to concentration changes, indicating that both species are in chemical equilibrium, with the monomer and the dimer having different electrochemical characteristics. We associate this behaviour with the structural lability of the Cu(i) centre that allows the monomeric molecules to reorder conformationally to achieve a more adequate assembly in the non-covalent dimer. As expected, structural properties in the solid and in solution, as well as their electrochemical properties, are not correlated with the electronic parameters usually used to evaluate R substituent effects. This confirms that the properties of the Cu(i) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative equilibria.
publishDate 2022
dc.date.none.fl_str_mv 2022-12
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/202670
Cáceres Vázquez, Joaquín; Jara, Danilo H.; Costamagna, Juan; Martínez Gómez, Fabián; Silva, Carlos; et al.; Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes; Royal Society of Chemistry; RSC Advances; 13; 2; 12-2022; 825-838
2046-2069
CONICET Digital
CONICET
url http://hdl.handle.net/11336/202670
identifier_str_mv Cáceres Vázquez, Joaquín; Jara, Danilo H.; Costamagna, Juan; Martínez Gómez, Fabián; Silva, Carlos; et al.; Effect of non-covalent self-dimerization on the spectroscopic and electrochemical properties of mixed Cu(i) complexes; Royal Society of Chemistry; RSC Advances; 13; 2; 12-2022; 825-838
2046-2069
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1039/d2ra05341a
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Royal Society of Chemistry
publisher.none.fl_str_mv Royal Society of Chemistry
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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