Synthesis and Structural Characterization of [Ir4(mu-CO)(CO)7{mu4-eta3-Ph2PC(H)C(Ph)PCBu t}(mu-PPh2)]: Alkyne-Phosphaalkyne Coupling and Formation of a Novel 2-phosphabutadienylphosphine Ligand

Abstract

Braz. Chem. Soc., Vol. 9, No. 6, 563-570, 1998. © 1998 0103 --5053 $6.00 + 0.00 a butterfly arrangement of iridium atoms with the new ligand interacting with the metal framework via four σ bonds and the PPh2 phosphorus lone pair.

X-ray molecular structures and multinuclear NMR studies of the tetranuclear iridium clusters [Ir4(CO)7(μ4-η3-PhCC(H)CCPh)(μ-PPh2)3] and [Ir4(CO)7(μ3-η2-HCCPh)(η1-CCPh)(μ-PPh2)3]

“…Ir (1) (4) [25]. These assignments, for compounds 2 and 3, were confirmed by a 2D-HSQC experiment, which showed the correlation between the signal at d 125.21 (s) and that at d 6.33 (m), for 2, and the correlation between the signal at d 110.98 (s) and that at d 8.76 (dd), for 3.…”

Carbon–carbon coupling on tetrahedral iridium clusters: X-ray molecular structures and multinuclear NMR studies of the two isomeric forms of [Ir4(CO)6(μ3-η2-HCCPh)(μ2-η4-C4H2Ph2)(μ-PPh2)2]

“…doi:10.1016/j.jorganchem.2004.08.010 this tetranuclear cluster under thermolytic conditions with C 2 (COOMe) 2 , to yield [Ir 4 (CO) 8 {C 2 (COOMe) 2 } 4 ] [22], and with cod (cod = cyclooctadiene), to give the alkyne containing clusters [Ir 4 (CO) 5 (cod) 2 (C 8 H 10 )] and [Ir 7 -(CO) 12 (cod)(C 8 H 11 )(C 8 H 10 )] [23,24] all in very low yields, and that of the oxidation of [Ir 6 (CO) 15 ] 2À with ferrocinium in the presence of PhCCPh to yield [Ir 6 -(CO) 14 (l 3 -g 2 -HCCPh)] and [Ir 6 (CO) 12 (l 3 -g 2 -HCCPh) 2 ] [25]. The cluster [HIr 4 (CO) 10 (l-PPh 2 )] [26] has proven itself a good entry into tetranuclear iridium organometallic chemistry [27][28][29][30][31][32][33][34][35]. Its derivative [HIr 4 -(CO) 9 (Ph 2 PC"CPh)(l-PPh 2 )] (1) undergoes a selective rearrangement under mild conditions to give [Ir 4 -(CO) 8 (l 3 -g 2 -HCCPh)(l-PPh 2 ) 2 ] (2) [34].…”