OXIDATIVE ADDITION OF PHENYLACETYLENE TO [IR(CO)(RCN)(PPH(3))(2)]CLO4- PREPARATION, KINETICS, AND MECHANISM

Citation
Cs. Chin et al., OXIDATIVE ADDITION OF PHENYLACETYLENE TO [IR(CO)(RCN)(PPH(3))(2)]CLO4- PREPARATION, KINETICS, AND MECHANISM, Inorganic chemistry, 32(26), 1993, pp. 5901-5904
Citations number
45
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
ISSN journal
00201669
Volume
32
Issue
26
Year of publication
1993
Pages
5901 - 5904
Database
ISI
SICI code
0020-1669(1993)32:26<5901:OAOPT[>2.0.ZU;2-0
Abstract
Reactions of PhC=CH (la) and p-CH3C6H4C=CH (1b) with [Ir(RCN)(CO)(PPh( 3))(2)]ClO4, 2 (R = Ph (a), CH3 (b), CH=CHPh (c)), give [Ir(H)(-C=CR') (RCN)(CO)(PPh(3))(2)]ClO4, 3 (R' = Ph, R = Ph (a), CH3 (b), CH=CHPh (c ); R' = P-CH3C6H4, R = Ph (d)), where the hydride is cis both to two P Ph(3) groups and trans to RCN. The oxidative addition of 1a to 2a,b is first order both in 1a and 2a,b and depressed by the presence of RCN added. The suggested reaction pathway involves the initial replacement of RCN of 2a,b by 1a to give [Ir(PhC=CH).(CO)(PPh(3))(2)]ClO4, which undergoes an intramolecular oxidative cleavage of the coordinated 1a t o give [Ir(H)(-C=CPh)(CO) (PPh(3))(2)]ClO4, to which RCN is added back to give the stable complexes 3a,b. Kinetic data obtained for alkyne h ydrogen deuterated phenylacetylene, PhC=CD (1a-d), support the suggest ed mechanism.