Stable Carbeneiridium(I) Complexes with 16- and 18-Electron Configurations at the Metal Center

Abstract

Using the mixed phosphine−stibine compound [IrCl(C2H4)(PiPr3)(SbiPr3)] (2) as the starting material, the square-planar carbeneiridium(I) complexes [IrCl(CR2)(PiPr3)(SbiPr3)] (3a,b) and trans-[IrCl(CR2)(PiPr3)2] (4a,b) were prepared. The cyclopentadienyl derivative [C5H5Ir(CPh2)(PiPr3)] (5), obtained from 3a and NaC5H5, reacts with HCl by attack of the IrCPh2 bond; in contrast, upon treatment of 4a with HCl or HBF4, hydridoiridium(III) complexes 8 and 9 with an intact IrCPh2 unit are formed.

N‐Heterocyclic Carbene Functionalized Iridium Phosphinidene Complex [Cp*(NHC)IrPMes*]: Comparison of Phosphinidene, Imido, and Carbene Complexes

“…[14] These distances are shortened with respect to normal Ir À C single bonds ($ 2.1 ä) [18] and longer than IrC double bonds. [12] The latter can be illustrated by the short IrC distance in 6 (1.890 ä) which agrees well with the experimentally known Ir alkylidene complex [Cp*(PiPr 3 )IrCPh 2 ] (1.904 ä). [12] The longer IrÀC(NHC) bond lengths in 4 ± 6 mirror the different nature of the metal ± carbene bonds with respect to alkylidene moieties.…”

“…[12] The latter can be illustrated by the short IrC distance in 6 (1.890 ä) which agrees well with the experimentally known Ir alkylidene complex [Cp*(PiPr 3 )IrCPh 2 ] (1.904 ä). [12] The longer IrÀC(NHC) bond lengths in 4 ± 6 mirror the different nature of the metal ± carbene bonds with respect to alkylidene moieties. Interestingly, the difference between the Ir C and Ir À C(NHC) distances of 0.08 ä in 6 is much less pronounced compared with NHC ligated Ru alkylidene complexes (0.23 ± 0.30 ä).…”

“…Furthermore, structural and bonding properties for the iridium phosphinidene parent complex that contains the imidazol-2-ylidene ligand is evaluated theoretically, and comparisons are made with analogous alkylidene and imido complexes. The transition metal iridium is used because similar alkylidene, [11,12] imido, [13] phosphinidene, [9] as well as N-heterocyclic carbene complexes [14] are known experimentally for iridium. [14] and confirms the presence of the carbene moiety in 2.…”

Iridium(I)- und Iridium(III)-Komplexe mit Triisopropylarsan als Ligand

“…In den letzten Jahren haben wir in einer Reihe von Arbeiten gezeigt, dass das Moleku È lfragment [IrCl(PiPr 3 ) 2 ] ein ausgezeichnetes ¹Stu È tzkorsettª fu È r die Koordination so unterschiedlicher Liganden wie C 2 H 2 [1], C 2 H 4 [2], CPh 2 [3], C=CR 2 [4], C=C=CPh 2 [5], C=C=C=CPh 2 [6], C=C=C=C=CPh 2 [7] und N 2 [8] ist. Wir hatten in ju È ngster Zeit ebenfalls darauf hingewiesen, dass es Unterschiede in der Koordinationsfa È higkeit von PiPr 3 und SbiPr 3 In Abb.…”

“…Wir hatten in ju È ngster Zeit ebenfalls darauf hingewiesen, dass es Unterschiede in der Koordinationsfa È higkeit von PiPr 3 und SbiPr 3 In Abb. 1 ist das Ergebnis der Kristallstrukturanalyse von 5 gezeigt.…”