Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.26/21981
Título: Indenyl ring slippage in crown thioether complexes [IndMo(CO)2L]+ and C–S activation of trithiacyclononane: Experimental and theoretical studies
Autor: Gamelas, Carla A.
Bandeira, Nuno
Pereira, Cláudia
Calhorda, Maria José
Herdtweck, Eberhardt
Machuqueiro, Miguel
Romão, Carlos
Veiros, Luís
Data: 2011
Citação: Gamelas, C., Bandeira, N., Pereira, C., Calhorda, M. J., Herdtweck, E., Machuqueiro, M. … Veiros, L.(2011). Indenyl ring slippage in crown thioether complexes [IndMo(CO)2L]+ and C–S activation of trithiacyclononane: Experimental and theoretical studies. Dalton Transactions, 40, pp. 10513 - 10513. doi: 10.1039/C1DT10607D.
Resumo: The macrocycle 1,4,7-trithiacyclononane (ttcn) reacts with [(η5-Ind)Mo(CO)2(NCMe)2]+ (or [(η5-Ind)Mo(CO)2(κ2-dme)]+) to give [(η3-Ind)Mo(CO)2(κ3-ttcn)]+ as the BF4− salt (1), but its reaction with [(η5-Ind)Mo(CO)2(C3H6)(FBF3)] affords the C–S bond cleavage product [(η5-Ind)Mo(CO)(κ3-1,4,7-trithiaheptanate)]BF4 (6), which has been characterised by X-ray crystallography (Ind = C9H7, indenyl). In contrast to ttcn, the macrocycles 1,3,5-trithiane (tt) and 1,4,7,10-tetrathiacyclododecane (ttcd) fail to induce changes in the coordination mode of indenyl: tt and ttcd react with [(η5-Ind)Mo(CO)2(NCMe)2]+ (or [(η5-Ind)Mo(CO)2(κ2-dme)]+) to give [(η5-Ind)Mo(CO)2(κ2-tt)]+ (2), characterised by X-ray crystallography, and [(η5-Ind)Mo(CO)2(κ2-ttcd)]+ (3), respectively. The cyclopentadienyl (Cp = C5H5) analogues [(η5-CpMo(CO)2(κ2-tt)]+ (4) and [(η5-CpMo(CO)2(κ2-ttcn)]+ (5) have also been synthesised and 5 characterised by X-ray crystallography. DFT calculations showed that the η5-Ind/Cp coordination mode is always the most stable. However, a molecular dynamics study of the macrocycles conformations revealed that the major conformer of ttcn was a chair, which favoured κ3 coordination. As indenyl complexes undergo slippage with a small barrier (<10 kcal mol−1), the kinetically preferred species [(η3-Ind)Mo(CO)2(κ3-ttcn)]+ (1) is the observed one. The conversion to 6 proceeds stepwise, with loss of ethylene followed by loss of CO, as calculated by DFT, with a barrier of 38.7 kcal mol−1, consistent with the slow uncatalysed reaction.
Peer review: yes
URI: http://hdl.handle.net/10400.26/21981
DOI: 10.1039/C1DT10607D
Aparece nas colecções:IPS - ESTS – DSI - Artigos científicos

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
Artigo 3-Dalton Transactions 40, 40, 10513-10513.pdf915,46 kBAdobe PDFVer/Abrir    Acesso Restrito. Solicitar cópia ao autor!


FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Degois 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.