DUTTA , D K and WOOLLINS , J D and SLAWIN , A M Z and KONWAR , D and SHARMA , M and BHATTACHARYYA , P and AUCOTT , S M
(2006)
Rhodium(I) carbonyl complexes of mono selenium functionalized enylphosphino)methane and Bis(di- phenylphosphino)amine chelating ligands and their catalytic carbonylation activity.
J Organometallic Chemistry, 69.
pp. 1229-1234.
Abstract
The chelate complexes of the types [Rh(CO)Cl(Ph2PCH2P(Se)Ph2)] (1) and [Rh(CO)Cl(Ph2PN(CH3)P(Se)Ph2)] (2) have been synthesized
and characterized by IR and NMR spectroscopy. The lower shift of the m(P–Se) bands and downfield shift of the 31P–
{ 1H}NMR signals for both P(III) and P(V) atoms in 1 and 2 compared to the corresponding free ligands indicate chelate formation
through selenium donor. 1 and 2 show terminalm(CO) bands at 1977 and 1981cm 1, respectively, suggesting high electron density at
themetalcenter.Themolecularstructureof2hasbeendeterminedbysingle-crystalX-raydiffraction.Therhodiumatomisatthecenter
ofasquareplanargeometryhavingthephosphorusandseleniumatomsofthechelatingligandatcis-position,onecarbonylgrouptransto
selenium and one chlorine atom trans- to phosphorus atom. 1 and 2 undergo oxidative addition (OA) reaction with CH 3I to produce
acyl complexes [Rh(COCH3)ClI(Ph2PCH2P(Se)Ph2)] (3) and [Rh(COCH3)ClI(Ph2PN(CH3)P(Se)Ph2)] (4), respectively. The kinetics of the
OAreactionsrevealthat1undergoesfasterreactionbyabout4.5timesthan2.Thecatalyticactivityof1and2incarbonylationofmethanol
was higher than that of the well known species [Rh(CO) 2I2] and 2 shows higher catalytic activity compared to 1.
2005 Elsevier B.V. All rights reserved.
Keywords: Rhodium(I) carbonyl complexes; Bis(diphenylphosphino)methane selenide; Bis(diphenylphosphino)amine selenide; Oxidative addition;
Carbonylation
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