Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)

Autores
Melo, Juan Ignacio; Maldonado, Alejandro Fabián; Aucar, Gustavo Adolfo
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX2I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ∼ 97 (93) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1 of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CHnX4 - n (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF2X for which σnr(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH3X (X = F, Cl, Br and I), we found that σSO ∼ ZX2.53. Another important finding of this work is the logarithmic dependence of σSO(C) with the substituent atomic number: ln σSO(C) = AX aX Z Y for both family of compounds CH2XY and CHX2Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework. © 2012 American Institute of Physics.
Fil: Melo, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina
Fil: Maldonado, Alejandro Fabián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina
Fil: Aucar, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina
Materia
RELATIVISTIC EFFECTS
NUCLEAR MAGNETIC SHIELDINGS
LRESC
SPIN FREE
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/149289

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network_name_str CONICET Digital (CONICET)
spelling Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)Melo, Juan IgnacioMaldonado, Alejandro FabiánAucar, Gustavo AdolfoRELATIVISTIC EFFECTSNUCLEAR MAGNETIC SHIELDINGSLRESCSPIN FREEhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX2I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ∼ 97 (93) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1 of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CHnX4 - n (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF2X for which σnr(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH3X (X = F, Cl, Br and I), we found that σSO ∼ ZX2.53. Another important finding of this work is the logarithmic dependence of σSO(C) with the substituent atomic number: ln σSO(C) = AX aX Z Y for both family of compounds CH2XY and CHX2Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework. © 2012 American Institute of Physics.Fil: Melo, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Maldonado, Alejandro Fabián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Aucar, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaAmerican Institute of Physics2012-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/149289Melo, Juan Ignacio; Maldonado, Alejandro Fabián; Aucar, Gustavo Adolfo; Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I); American Institute of Physics; Journal of Chemical Physics; 137; 21; 12-2012; 1-120021-9606CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1063/1.4768470info:eu-repo/semantics/altIdentifier/url/https://aip.scitation.org/doi/10.1063/1.4768470info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:43:30Zoai:ri.conicet.gov.ar:11336/149289instacron: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 10:43:30.956CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
title Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
spellingShingle Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
Melo, Juan Ignacio
RELATIVISTIC EFFECTS
NUCLEAR MAGNETIC SHIELDINGS
LRESC
SPIN FREE
title_short Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
title_full Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
title_fullStr Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
title_full_unstemmed Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
title_sort Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)
dc.creator.none.fl_str_mv Melo, Juan Ignacio
Maldonado, Alejandro Fabián
Aucar, Gustavo Adolfo
author Melo, Juan Ignacio
author_facet Melo, Juan Ignacio
Maldonado, Alejandro Fabián
Aucar, Gustavo Adolfo
author_role author
author2 Maldonado, Alejandro Fabián
Aucar, Gustavo Adolfo
author2_role author
author
dc.subject.none.fl_str_mv RELATIVISTIC EFFECTS
NUCLEAR MAGNETIC SHIELDINGS
LRESC
SPIN FREE
topic RELATIVISTIC EFFECTS
NUCLEAR MAGNETIC SHIELDINGS
LRESC
SPIN FREE
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX2I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ∼ 97 (93) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1 of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CHnX4 - n (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF2X for which σnr(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH3X (X = F, Cl, Br and I), we found that σSO ∼ ZX2.53. Another important finding of this work is the logarithmic dependence of σSO(C) with the substituent atomic number: ln σSO(C) = AX aX Z Y for both family of compounds CH2XY and CHX2Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework. © 2012 American Institute of Physics.
Fil: Melo, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina
Fil: Maldonado, Alejandro Fabián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina
Fil: Aucar, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina
description Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX2I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ∼ 97 (93) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1 of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CHnX4 - n (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF2X for which σnr(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH3X (X = F, Cl, Br and I), we found that σSO ∼ ZX2.53. Another important finding of this work is the logarithmic dependence of σSO(C) with the substituent atomic number: ln σSO(C) = AX aX Z Y for both family of compounds CH2XY and CHX2Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework. © 2012 American Institute of Physics.
publishDate 2012
dc.date.none.fl_str_mv 2012-12
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/11336/149289
Melo, Juan Ignacio; Maldonado, Alejandro Fabián; Aucar, Gustavo Adolfo; Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I); American Institute of Physics; Journal of Chemical Physics; 137; 21; 12-2012; 1-12
0021-9606
CONICET Digital
CONICET
url http://hdl.handle.net/11336/149289
identifier_str_mv Melo, Juan Ignacio; Maldonado, Alejandro Fabián; Aucar, Gustavo Adolfo; Relativistic effects on nuclear magnetic shieldings of CHnX4−n and CHXYZ (X, Y, Z = H, F, Cl, Br, I); American Institute of Physics; Journal of Chemical Physics; 137; 21; 12-2012; 1-12
0021-9606
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
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info:eu-repo/semantics/altIdentifier/url/https://aip.scitation.org/doi/10.1063/1.4768470
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
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application/pdf
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dc.publisher.none.fl_str_mv American Institute of Physics
publisher.none.fl_str_mv American Institute of Physics
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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