resumo
The complex [{(eta(5)-Ind)Mo(CO)(2)(mu-CI)(2)] (1) has been tested for the industrially relevant catalytic isomerisation of CL-pinene oxide (PinOx) to campholenic aldehyde (CPA) in the liquid phase. PinOx conversion and CPA selectivity are strongly influenced by the solvent employed. Complete conversion of PinOx was achieved within 1 min at 55 degrees C or 30 min at 35 degrees C using 1,2-dichloroethane as solvent, giving CPA in 68% yield. Other products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The stability of 1 under the reaction conditions used was investigated by using FT-IR spectroscopy and electrospray ionisation mass spectrometry (ESI-MS) to characterise recovered solids. In the presence of air/moisture 1 undergoes oxidative decarbonylation upon dissolution to give oxomolybdenum species that are proposed to include a tetranuclear oxomolybdenum(v) complex. Conversely, ESI-MS studies of 1 dissolved in dry acetonitrile show mononuclear species of the type [IndMo(CO)(2)(CH3CN)(n)](+) The crystal structure of the ring-slipped dicarbonyl complex [{(eta(5)-Ind)Mo(CO)(2)(mu-CI)(2)] (2) (obtained after dissolution of 1 in acetonitrile) is reported.
palavras-chave
CAMBRIDGE STRUCTURAL DATABASE; X-RAY-STRUCTURE; ABSOLUTE-CONFIGURATION; MOLECULAR-STRUCTURES; SANDWICH COMPLEXES; CRYSTAL-STRUCTURES; RING SLIPPAGE; LEWIS-ACIDS; MIXED-RING; PRECURSORS
categoria
Chemistry
autores
Bruno, SM; Gomes, AC; Gamelas, CA; Abrantes, M; Oliveira, MC; Valente, AA; Paz, FAA; Pillinger, M; Romao, CC; Goncalves, IS
nossos autores
Ana Catarina Costa Gomes Alves
Investigador Auxiliar
Anabela Tavares Aguiar Valente
Investigador Principal
Filipe Alexandre Almeida Paz
Investigador Principal
Isabel Maria de Sousa Gonçalves
Professor associado
Martyn Pillinger
Investigador Principal
Sofia M. Bruno
Investigador AuxiliarProjectos
Use of molecular containers to modify metallocene-based catalysts (PTDC/QEQ-SUP/1906/2012)
PTNMR - Portuguese Nuclear Magnetic Resonance Network (REDE/1517/RMN/2005)
agradecimentos
This work was partly financed by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE (Programa Operacional Factores de Competitividade) and by national funds through the FCT (Fundacao para a Ciencia e a Tecnologia) with the projects CICECO - FCOMP-01-0124-FEDER-037271 (FCT ref. PEst-C/CTM/LA0011/2013), FCOMP-01-0124-FEDER029779 (FCT ref. PTDC/QEQ-SUP/1906/2012, including the research grant with ref. BPD/UI89/4864/2013 to A.C.G), the Centro de Quimica Estrutural (PEst-OE/QUI/UI0100/2013), and REM 2013. The FCT and the European Union are acknowledged for a post-doctoral grant to S.M.B. (ref. SFRH/BPD/46473/ 2008) cofunded by MCTES and the European Social Fund through the program POPH of QREN. We further wish to thank the FCT for specific funding towards the purchase of the singlecrystal diffractometer. The NMR spectrometers used are part of The National NMR Network (REDE/1517/RMN/2005), supported by POCI 2010 and the FCT. The authors thank the Portuguese NMR Network (IST-UTL Center) (RECl/QEQ-QIN/0189/2012) for providing access to the NMR facilities.