INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS
Autor(a) principal: | |
---|---|
Data de Publicação: | 2018 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Química Nova (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000900999 |
Resumo: | The kinetics of photoisomerization and thermal back reaction of mercury(II) and zinc(II) dithizonates, M(HDz)2, were analyzed by photolysis assays in fluid solution and in poly(methyl methacrylate), PMMA, films. In fluid solution, the photo- and thermoisomerization of both complexes can be described by a single exponential function. The Zn(II) dithizonate exhibits rate constants three orders of magnitude greater than that for Hg(II) complex, which is attributed to the higher charge density of the Zn(II) cation. In PMMA films, the thermal back reaction of both complexes can only be described by bi-exponential functions. On this more rigid medium the rate constants are about one order of magnitude slower than the respective ones in fluid solution and the bi-exponential behavior is related to regions in the polymeric matrix with distinct free volumes. The rate constants for both photo- and thermoisomerization of Zn(HDz)2 in PMMA are reported for the first time and are compared with the well-studied Hg(II) analog. The experimental data provides insights on the role of the metal cation on the photocromic behavior in rigid media, which can lately contribute for technological applications. |
id |
SBQ-3_0eb9aa740777d2ab02f13e9f21812333 |
---|---|
oai_identifier_str |
oai:scielo:S0100-40422018000900999 |
network_acronym_str |
SBQ-3 |
network_name_str |
Química Nova (Online) |
repository_id_str |
|
spelling |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOSphotochromismmetal dithizonatesphotoisomerizationThe kinetics of photoisomerization and thermal back reaction of mercury(II) and zinc(II) dithizonates, M(HDz)2, were analyzed by photolysis assays in fluid solution and in poly(methyl methacrylate), PMMA, films. In fluid solution, the photo- and thermoisomerization of both complexes can be described by a single exponential function. The Zn(II) dithizonate exhibits rate constants three orders of magnitude greater than that for Hg(II) complex, which is attributed to the higher charge density of the Zn(II) cation. In PMMA films, the thermal back reaction of both complexes can only be described by bi-exponential functions. On this more rigid medium the rate constants are about one order of magnitude slower than the respective ones in fluid solution and the bi-exponential behavior is related to regions in the polymeric matrix with distinct free volumes. The rate constants for both photo- and thermoisomerization of Zn(HDz)2 in PMMA are reported for the first time and are compared with the well-studied Hg(II) analog. The experimental data provides insights on the role of the metal cation on the photocromic behavior in rigid media, which can lately contribute for technological applications.Sociedade Brasileira de Química2018-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000900999Química Nova v.41 n.9 2018reponame:Química Nova (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.21577/0100-4042.20170280info:eu-repo/semantics/openAccessBarros,Cristiane Lázara deBarbosa Neto,Newton MartinsPatrocinio,Antonio Otavio T.por2018-10-11T00:00:00Zoai:scielo:S0100-40422018000900999Revistahttps://www.scielo.br/j/qn/ONGhttps://old.scielo.br/oai/scielo-oai.phpquimicanova@sbq.org.br1678-70640100-4042opendoar:2018-10-11T00:00Química Nova (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
title |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
spellingShingle |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS Barros,Cristiane Lázara de photochromism metal dithizonates photoisomerization |
title_short |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
title_full |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
title_fullStr |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
title_full_unstemmed |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
title_sort |
INFLUÊNCIA DA RIGIDEZ DO MEIO NA CINÉTICA DO FOTOCROMISMO DE DITIZONATOS METÁLICOS |
author |
Barros,Cristiane Lázara de |
author_facet |
Barros,Cristiane Lázara de Barbosa Neto,Newton Martins Patrocinio,Antonio Otavio T. |
author_role |
author |
author2 |
Barbosa Neto,Newton Martins Patrocinio,Antonio Otavio T. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Barros,Cristiane Lázara de Barbosa Neto,Newton Martins Patrocinio,Antonio Otavio T. |
dc.subject.por.fl_str_mv |
photochromism metal dithizonates photoisomerization |
topic |
photochromism metal dithizonates photoisomerization |
description |
The kinetics of photoisomerization and thermal back reaction of mercury(II) and zinc(II) dithizonates, M(HDz)2, were analyzed by photolysis assays in fluid solution and in poly(methyl methacrylate), PMMA, films. In fluid solution, the photo- and thermoisomerization of both complexes can be described by a single exponential function. The Zn(II) dithizonate exhibits rate constants three orders of magnitude greater than that for Hg(II) complex, which is attributed to the higher charge density of the Zn(II) cation. In PMMA films, the thermal back reaction of both complexes can only be described by bi-exponential functions. On this more rigid medium the rate constants are about one order of magnitude slower than the respective ones in fluid solution and the bi-exponential behavior is related to regions in the polymeric matrix with distinct free volumes. The rate constants for both photo- and thermoisomerization of Zn(HDz)2 in PMMA are reported for the first time and are compared with the well-studied Hg(II) analog. The experimental data provides insights on the role of the metal cation on the photocromic behavior in rigid media, which can lately contribute for technological applications. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-09-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000900999 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000900999 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
10.21577/0100-4042.20170280 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Química Nova v.41 n.9 2018 reponame:Química Nova (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Química Nova (Online) |
collection |
Química Nova (Online) |
repository.name.fl_str_mv |
Química Nova (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
quimicanova@sbq.org.br |
_version_ |
1750318119243481088 |