Premium
Synthesis, Spectroscopy, and Hydroformylation Activity of Sterically Demanding, Phosphite‐Modified Cobalt Catalysts
Author(s) -
Meijboom Reinout,
Haumann Marco,
Roodt Andreas,
Damoense Llewellyn
Publication year - 2005
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200590047
Subject(s) - chemistry , hydroformylation , steric effects , cobalt , catalysis , nuclear magnetic resonance spectroscopy , crystallography , hydride , spectroscopy , infrared spectroscopy , medicinal chemistry , stereochemistry , rhodium , inorganic chemistry , organic chemistry , hydrogen , physics , quantum mechanics
The dinuclear complex [Co 2 (CO) 6 {P(O‐2,4‐ t ‐Bu 2 C 6 H 3 ) 3 } 2 ] ( 6 ) has been synthesised and fully characterised. X‐Ray crystal‐structure analysis revealed a trans ‐diaxial geometry, no bridging carbonyls, and CoCo and CoP bond lengths of 2.706(5) and 2.134(4) Å, respectively. The hydroformylation of pent‐1‐ene in the presence of 6 was studied at 120–180° at pressures between 20 and 80 bar Syngas. High‐pressure (HP) spectroscopy (IR, NMR) was used to detect potential hydride intermediates. HP‐IR Studies revealed the formation of [CoH(CO) 3 {P(O‐2,4‐ t ‐Bu 2 C 6 H 3 ) 3 }] ( 2 ) at ca. 105°, with no significant amount of [CoH(CO) 4 ] detectable. The intermediate 2 was synthesised and characterised. The formation of the undesired complex [CoH(CO) 2 {P(O‐2,4‐ t ‐Bu 2 C 6 H 3 ) 3 } 2 ] was completely suppressed due to the large cone angle of the sterically demanding phosphite.