Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas
Autor(a) principal: | |
---|---|
Data de Publicação: | 2010 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/4195 |
Resumo: | This work describes the molecular and supramolecular structure of fourteen pyrazolo[1,5-a]pyrimidines from bond lengths, torsion angles, angles between planes and interatomic distances. The data discussed were originated from xray and theoretical calculations. Torsion angle N1-N8-C3a-N4, algles between planes of pyrazole and pyrimidine rings and the pyrazolo[1,5-a]pyrimidine RMS value showed that the fused rings are plane. The heterocyclic ring bond lengths demonstrated that the p-electrons are delocalized by resonance and the peripheral electronic distribution of this p-electrons is similar to the naphthalene. The bond length obtained from theoretical calculations (AM1, PM3, RM1 e ab initio) have a correlation with experimental for pyrazolo[1,5-a]pyrimidine ring bonds and for bonds of their substituents.The supramolecular assembly of pyrazolo[1,5-a]pyrimidine reveals that interactions type halogen···Lewis base (Cl···N, F···F, Cl···Cl, Cl···Br), halogen···p (F···p, Cl···p e Br···p) and p-p interactions (pyrazole, pyrimidine and aryl) were the main interactions observed by self-assembly of the pyrazolo[1,5-a]pyrimidines. The atoms in supramolecular synthons were invariable with modifications of substituent at C5. However, was sensitive to variations of substituents at C3. This composes a notable example of substituent effect in the synthon robustness. The halogenated functions at C7(CCl3, CF3), C3 (Br) and in remote positions at C5 (4-Br-Ph) present the competition between chlorine and bromine atoms in the formation of supramolecular synthons. These observations are in accordance with recent s-hole theory and are some of few experimental example of theory. Finally, the aromaticity of pyrazolo[1,5-a]pyrimidines was determined by geometric index HOMA (Harmonic Oscillator Model of Aromaticity) from theoretical (AM1, PM3, RM1 e ab initio) and x-ray bond length. In this work, was also proposing new parameters to heterocyclic HOMA calculations. The results show HOMA values higher than 0.900 that is in accordance with aromaticity properties of these systems. |
id |
UFSM_6158db0f07cb9e6a26ddb02451c5352d |
---|---|
oai_identifier_str |
oai:repositorio.ufsm.br:1/4195 |
network_acronym_str |
UFSM |
network_name_str |
Manancial - Repositório Digital da UFSM |
repository_id_str |
|
spelling |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinasMolecular and Supramolecular Structure of Pyrazolo[1,5- a]pyrimidinesPirazolo[1,5-a]pirimidinasRaios-XEstrutura molecularAgregação supramolecularAromaticidadeCálculos de orbitais molecularesPyrazolo[1,5-a]pyrimidinesX-ray, molecular structureSelfassemblyAromaticityHOMAMO calculationsCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAThis work describes the molecular and supramolecular structure of fourteen pyrazolo[1,5-a]pyrimidines from bond lengths, torsion angles, angles between planes and interatomic distances. The data discussed were originated from xray and theoretical calculations. Torsion angle N1-N8-C3a-N4, algles between planes of pyrazole and pyrimidine rings and the pyrazolo[1,5-a]pyrimidine RMS value showed that the fused rings are plane. The heterocyclic ring bond lengths demonstrated that the p-electrons are delocalized by resonance and the peripheral electronic distribution of this p-electrons is similar to the naphthalene. The bond length obtained from theoretical calculations (AM1, PM3, RM1 e ab initio) have a correlation with experimental for pyrazolo[1,5-a]pyrimidine ring bonds and for bonds of their substituents.The supramolecular assembly of pyrazolo[1,5-a]pyrimidine reveals that interactions type halogen···Lewis base (Cl···N, F···F, Cl···Cl, Cl···Br), halogen···p (F···p, Cl···p e Br···p) and p-p interactions (pyrazole, pyrimidine and aryl) were the main interactions observed by self-assembly of the pyrazolo[1,5-a]pyrimidines. The atoms in supramolecular synthons were invariable with modifications of substituent at C5. However, was sensitive to variations of substituents at C3. This composes a notable example of substituent effect in the synthon robustness. The halogenated functions at C7(CCl3, CF3), C3 (Br) and in remote positions at C5 (4-Br-Ph) present the competition between chlorine and bromine atoms in the formation of supramolecular synthons. These observations are in accordance with recent s-hole theory and are some of few experimental example of theory. Finally, the aromaticity of pyrazolo[1,5-a]pyrimidines was determined by geometric index HOMA (Harmonic Oscillator Model of Aromaticity) from theoretical (AM1, PM3, RM1 e ab initio) and x-ray bond length. In this work, was also proposing new parameters to heterocyclic HOMA calculations. The results show HOMA values higher than 0.900 that is in accordance with aromaticity properties of these systems.Conselho Nacional de Desenvolvimento Científico e TecnológicoEste trabalho apresenta o estudo da estrutura molecular e supramolecular de uma série de 14 pirazolo[1,5-a]pirimidinas a partir de dados de comprimentos e ângulos de ligação, ângulos diedros, ângulos entre planos, distâncias interatômica de interações intermoleculares. Os dados apresentados foram obtidos por difratometria de raios-X e cálculos teóricos de orbitais moleculares. Os dados do ângulo diedro N1-N8-C3a-N4, ângulo entre os planos do pirazol e da pirimidina, e a média da raiz quadrada dos átomos do anel pirazol[1,5- a]pirimidina demonstraram que os anéis pirazol e pirimidina formadores do anel fundido estão no mesmo plano. Os comprimentos de ligação entre os átomos do núcleo heterocíclico demonstraram que os elétrons-p estão deslocalizados caracterizando um sistema em ressonância e que a distribuição eletrônica se assemelha a do naftaleno, com os elétrons distribuídos pela periferia do sistema heterocíclico. Os comprimentos de ligação obtidos por cálculos teóricos (Austin Method 1, Parametrized Method 3, Recife Method 1 e ab initio) apresentaram boa correlação com dados experimentais tanto para o núcleo pirazolo[1,5-a]pirimidina quanto para os substituintes. Ainda foram realizados estudos da organização supramolecular das pirazolo[1,5-a]pirimidina. As principais interações intermoleculares observadas nas pirazolo[1,5- a]pirimidinas foram do tipo halogênio···base de Lewis (Cl···N, F···F, Cl···Cl, Cl···Br), halogênio···p (F···p, Cl···p e Br···p) e interações do tipo p-p (entre anéis pirazol, pirimidina e arila). Os átomos envolvidos na interação foram persistentes com a variação do susbtituinte no C5 do anel. Entretanto as interações foram modificadas pela mudança de substituintes no C3 do anel, constituindo um exemplo notável do efeito do substituinte no empacotamento cristalino. A presença de funções halogenadas nas posições C7(CCl3, CF3), C3 (Br) e em posições remotas de substituintes em C5 (4-Br-Ph) mostraram a competição entre átomos de cloro e de bromo na organização supramolecular destes compostos. Estas observações estão de acordo com a recente teoria sobre a existência de uma superfície com potencial positivo na ligação Chalogênio (s-hole) e constituem um dos poucos exemplos experimentais para esta teoria. Por fim, foi determinada a aromaticidade de pirazolo[1,5-a]pirimidinas usando o índice geométrico HOMA (Harmonic Oscilator Model of Aromaticity) a partir dos dados de comprimentos de ligações obtidos por difratometria de raios-X e obtidos por cálculos teóricos (AM1, PM3, RM1 e ab initio). Neste trabalho também foram propostos novos parâmetros para a adequação do cálculo de aromaticidade para heterociclos. Os resultados mostraram valores de HOMA maiores que 0,900, que são condizentes com as características de aromaticidade descritas para estes compostos.Universidade Federal de Santa MariaBRQuímicaUFSMPrograma de Pós-Graduação em QuímicaMartins, Marcos Antonio Pintohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783192P3Samios, Dimitrioshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783958J5Fagan, Solange Binottohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4700282T5Back, Davi Fernandohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701590T6Bonacorso, Helio Gauzehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788537E0Frizzo, Clarissa Piccinin2010-11-092010-11-092010-05-07info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfapplication/pdfFRIZZO, Clarissa Piccinin. Molecular and Supramolecular Structure of Pyrazolo[1,5- a]pyrimidines. 2010. 261 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010.http://repositorio.ufsm.br/handle/1/4195porinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2017-07-25T14:05:06Zoai:repositorio.ufsm.br:1/4195Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2017-07-25T14:05:06Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas Molecular and Supramolecular Structure of Pyrazolo[1,5- a]pyrimidines |
title |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
spellingShingle |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas Frizzo, Clarissa Piccinin Pirazolo[1,5-a]pirimidinas Raios-X Estrutura molecular Agregação supramolecular Aromaticidade Cálculos de orbitais moleculares Pyrazolo[1,5-a]pyrimidines X-ray, molecular structure Selfassembly Aromaticity HOMA MO calculations CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
title_full |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
title_fullStr |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
title_full_unstemmed |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
title_sort |
Estrutura Molecular e Supramolecular de Pirazolo[1,5- a]pirimidinas |
author |
Frizzo, Clarissa Piccinin |
author_facet |
Frizzo, Clarissa Piccinin |
author_role |
author |
dc.contributor.none.fl_str_mv |
Martins, Marcos Antonio Pinto http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783192P3 Samios, Dimitrios http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783958J5 Fagan, Solange Binotto http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4700282T5 Back, Davi Fernando http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701590T6 Bonacorso, Helio Gauze http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788537E0 |
dc.contributor.author.fl_str_mv |
Frizzo, Clarissa Piccinin |
dc.subject.por.fl_str_mv |
Pirazolo[1,5-a]pirimidinas Raios-X Estrutura molecular Agregação supramolecular Aromaticidade Cálculos de orbitais moleculares Pyrazolo[1,5-a]pyrimidines X-ray, molecular structure Selfassembly Aromaticity HOMA MO calculations CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
topic |
Pirazolo[1,5-a]pirimidinas Raios-X Estrutura molecular Agregação supramolecular Aromaticidade Cálculos de orbitais moleculares Pyrazolo[1,5-a]pyrimidines X-ray, molecular structure Selfassembly Aromaticity HOMA MO calculations CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
This work describes the molecular and supramolecular structure of fourteen pyrazolo[1,5-a]pyrimidines from bond lengths, torsion angles, angles between planes and interatomic distances. The data discussed were originated from xray and theoretical calculations. Torsion angle N1-N8-C3a-N4, algles between planes of pyrazole and pyrimidine rings and the pyrazolo[1,5-a]pyrimidine RMS value showed that the fused rings are plane. The heterocyclic ring bond lengths demonstrated that the p-electrons are delocalized by resonance and the peripheral electronic distribution of this p-electrons is similar to the naphthalene. The bond length obtained from theoretical calculations (AM1, PM3, RM1 e ab initio) have a correlation with experimental for pyrazolo[1,5-a]pyrimidine ring bonds and for bonds of their substituents.The supramolecular assembly of pyrazolo[1,5-a]pyrimidine reveals that interactions type halogen···Lewis base (Cl···N, F···F, Cl···Cl, Cl···Br), halogen···p (F···p, Cl···p e Br···p) and p-p interactions (pyrazole, pyrimidine and aryl) were the main interactions observed by self-assembly of the pyrazolo[1,5-a]pyrimidines. The atoms in supramolecular synthons were invariable with modifications of substituent at C5. However, was sensitive to variations of substituents at C3. This composes a notable example of substituent effect in the synthon robustness. The halogenated functions at C7(CCl3, CF3), C3 (Br) and in remote positions at C5 (4-Br-Ph) present the competition between chlorine and bromine atoms in the formation of supramolecular synthons. These observations are in accordance with recent s-hole theory and are some of few experimental example of theory. Finally, the aromaticity of pyrazolo[1,5-a]pyrimidines was determined by geometric index HOMA (Harmonic Oscillator Model of Aromaticity) from theoretical (AM1, PM3, RM1 e ab initio) and x-ray bond length. In this work, was also proposing new parameters to heterocyclic HOMA calculations. The results show HOMA values higher than 0.900 that is in accordance with aromaticity properties of these systems. |
publishDate |
2010 |
dc.date.none.fl_str_mv |
2010-11-09 2010-11-09 2010-05-07 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
FRIZZO, Clarissa Piccinin. Molecular and Supramolecular Structure of Pyrazolo[1,5- a]pyrimidines. 2010. 261 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/4195 |
identifier_str_mv |
FRIZZO, Clarissa Piccinin. Molecular and Supramolecular Structure of Pyrazolo[1,5- a]pyrimidines. 2010. 261 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. |
url |
http://repositorio.ufsm.br/handle/1/4195 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
_version_ |
1805922163464601600 |