Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion
Autor(a) principal: | |
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Data de Publicação: | 1999 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000100007 |
Resumo: | Deprotonation of [(mu-H)Ir4(CO)10(mu-PPh2)], 1, gives [Ir4(CO)10(mu-PPh2)]- that reacts with Ph2PCCPh and CH3I to afford [Ir4(CO)8(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 2 (34%), besides [Ir4(CO)9(mu3-eta³-Ph2PC(H)CPh)(mu-PPh2)] and [(mu-H)Ir4(CO)9(Ph2PC<FONT FACE=Symbol>º</FONT>CPh)(mu-PPh2)]. Compound 2 was characterised by a single crystal X-ray diffraction analysis and exhibits a flat butterfly of metal atoms, with the Ph2PCCPh ligand interacting with all four Ir atoms and the methyl group bonded terminally to a wingtip Ir atom. Carbonylation of 2 yields initially (25 °C, 20 min) a CO addition product that, according to VT 31P{¹H} and 13C{¹H} studies, exists in solution in the form of two isomers 4A and 4B (8:1), and then (40 °C, 7 h), the CO insertion product [Ir4(CO)8{C(O)CH3}(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 5. The molecular structure of 5, established by an X-ray analysis, is similar to that of 2, except for the acyl group that remains bound to the same Ir atom. The process is reversible at both stages. Treatment of 2 with PPh3 and P(OMe)3 affords the CO substitution products [Ir4(CO)7L(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)] (L = PPh3, 6 and P(OMe)3, 7), instead of the expected CO inserted products. According to the ¹H and 31P{¹H} NMR studies, the PPh3 derivative 6 exists in the form of two isomers (1:1) that differ with respect to the position of this ligand. |
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Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertionmigratory insertioniridium carbonyl clustersalkyl clusterscarbonylationDeprotonation of [(mu-H)Ir4(CO)10(mu-PPh2)], 1, gives [Ir4(CO)10(mu-PPh2)]- that reacts with Ph2PCCPh and CH3I to afford [Ir4(CO)8(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 2 (34%), besides [Ir4(CO)9(mu3-eta³-Ph2PC(H)CPh)(mu-PPh2)] and [(mu-H)Ir4(CO)9(Ph2PC<FONT FACE=Symbol>º</FONT>CPh)(mu-PPh2)]. Compound 2 was characterised by a single crystal X-ray diffraction analysis and exhibits a flat butterfly of metal atoms, with the Ph2PCCPh ligand interacting with all four Ir atoms and the methyl group bonded terminally to a wingtip Ir atom. Carbonylation of 2 yields initially (25 °C, 20 min) a CO addition product that, according to VT 31P{¹H} and 13C{¹H} studies, exists in solution in the form of two isomers 4A and 4B (8:1), and then (40 °C, 7 h), the CO insertion product [Ir4(CO)8{C(O)CH3}(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 5. The molecular structure of 5, established by an X-ray analysis, is similar to that of 2, except for the acyl group that remains bound to the same Ir atom. The process is reversible at both stages. Treatment of 2 with PPh3 and P(OMe)3 affords the CO substitution products [Ir4(CO)7L(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)] (L = PPh3, 6 and P(OMe)3, 7), instead of the expected CO inserted products. According to the ¹H and 31P{¹H} NMR studies, the PPh3 derivative 6 exists in the form of two isomers (1:1) that differ with respect to the position of this ligand.Sociedade Brasileira de Química1999-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000100007Journal of the Brazilian Chemical Society v.10 n.1 1999reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50531999000100007info:eu-repo/semantics/openAccessBraga,DarioFujiwara,Fred Y.Grepioni,FabriziaPereira,Regina M.S.Vargas,Maria D.eng2002-10-23T00:00:00Zoai:scielo:S0103-50531999000100007Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2002-10-23T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
title |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
spellingShingle |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion Braga,Dario migratory insertion iridium carbonyl clusters alkyl clusters carbonylation |
title_short |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
title_full |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
title_fullStr |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
title_full_unstemmed |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
title_sort |
Synthesis and Structural Characterisation of [Ir4(CO)8(CH3)(mu4-eta3-Ph2PCCPh)(mu-PPh2)] and of the Carbonylation Product [Ir4(CO)8{C(O)CH3}(mu4-eta3-Ph2PCCPh)(mu-PPh2)]; First Evidence for the Formation of a CO Cluster Adduct before CO Insertion |
author |
Braga,Dario |
author_facet |
Braga,Dario Fujiwara,Fred Y. Grepioni,Fabrizia Pereira,Regina M.S. Vargas,Maria D. |
author_role |
author |
author2 |
Fujiwara,Fred Y. Grepioni,Fabrizia Pereira,Regina M.S. Vargas,Maria D. |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Braga,Dario Fujiwara,Fred Y. Grepioni,Fabrizia Pereira,Regina M.S. Vargas,Maria D. |
dc.subject.por.fl_str_mv |
migratory insertion iridium carbonyl clusters alkyl clusters carbonylation |
topic |
migratory insertion iridium carbonyl clusters alkyl clusters carbonylation |
description |
Deprotonation of [(mu-H)Ir4(CO)10(mu-PPh2)], 1, gives [Ir4(CO)10(mu-PPh2)]- that reacts with Ph2PCCPh and CH3I to afford [Ir4(CO)8(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 2 (34%), besides [Ir4(CO)9(mu3-eta³-Ph2PC(H)CPh)(mu-PPh2)] and [(mu-H)Ir4(CO)9(Ph2PC<FONT FACE=Symbol>º</FONT>CPh)(mu-PPh2)]. Compound 2 was characterised by a single crystal X-ray diffraction analysis and exhibits a flat butterfly of metal atoms, with the Ph2PCCPh ligand interacting with all four Ir atoms and the methyl group bonded terminally to a wingtip Ir atom. Carbonylation of 2 yields initially (25 °C, 20 min) a CO addition product that, according to VT 31P{¹H} and 13C{¹H} studies, exists in solution in the form of two isomers 4A and 4B (8:1), and then (40 °C, 7 h), the CO insertion product [Ir4(CO)8{C(O)CH3}(mu4-eta³-Ph2PCCPh)(mu-PPh2)], 5. The molecular structure of 5, established by an X-ray analysis, is similar to that of 2, except for the acyl group that remains bound to the same Ir atom. The process is reversible at both stages. Treatment of 2 with PPh3 and P(OMe)3 affords the CO substitution products [Ir4(CO)7L(CH3)(mu4-eta³-Ph2PCCPh)(mu-PPh2)] (L = PPh3, 6 and P(OMe)3, 7), instead of the expected CO inserted products. According to the ¹H and 31P{¹H} NMR studies, the PPh3 derivative 6 exists in the form of two isomers (1:1) that differ with respect to the position of this ligand. |
publishDate |
1999 |
dc.date.none.fl_str_mv |
1999-01-01 |
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=S0103-50531999000100007 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000100007 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50531999000100007 |
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 |
Journal of the Brazilian Chemical Society v.10 n.1 1999 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
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1750318163468222464 |