Diiridium complexes

The diiridium complex [Ir(CO)(PPh3)(/x-pz)]2 forms a diiridacyclobutene adduct of the type 143 with Me02CCsCC02Me, while the same reaction with F3CC=CCF3 leads to alkyne polymerization owing to dissociation of triphenyl-phosphine (85OM2106). 

The diiridium complex (IrCp )2(/U-S9)(/t-Sf-Pr)2 reacts with 3 equivalents of NaBPlq in CH2CI2/THF at room temperature to the formal Ir(III)/Ir(II)... 

Table 9.11 Diiridium complex 58-catalyzed alkyne dimerization.

Diiodo ligands, in platinum(II) complexes, 8, 504 Diiridium complexes, with bridging aryldiazenido ligands,... 

THE DIPHOSPHINE tfepma AND ITS DIIRIDIUM COMPLEX Ir20 II(tfepma)3Cl2... 

The Diphosphine tfepma and its Diiridium Complex Ir2° n(tfepma)sCl2 167... 

Desulfurization of thiophene by iridium complexes has been further investigated by Jones and coworkers using the diiridium complex [Cp IrH3]2(45). Thermal reaction of this bimetallic compound with thiophene in the presence of tert-butyl-ethylene leads directly to a product (46) in which both of the C-S bonds have been broken, leaving sulfide and butadiene ligands bridging the two iridium centers (Scheme 14). When d4-thiophene is used in this reaction, a d4-butadiene ligand is... 

The group of Jones has described the desulfurization of thiophene and benzothiophene using [Ir2(Cp )2(H)2(p-H)] with excess TBE (t-butylethylene) or [lr(Cl)(Cp )(H)]2 in the presence of H2 [53, 106]. The reactions evenmally afford diiridium complexes with sulfide and q q -butadiene bridges and seem to proceed via two consecutive carbon-sulfur bond cleavages that require more than one metal center and the ability to form bridging thiolate intermediates (Scheme 21) [107]. 

The 1,2,4-triazolium salt 102 (Figure 1.10) was prepared by Bertrand and co-workers. Even if all attempts to isolate the free dicarbene by deprotonation of the dication failed thus far, it was possible to obtain the mono- and disilver complexes by deprotonation and metalation of the carbon atoms of the hete-rocycle. Peris and co-workers obtained the diiridium complex by reaction of 102 (R = Me) with two equivalents of IrCl(COD)]2 in the presence of KOt-Bu. A heterobimetallic Ir Rh complex was obtained by successive reaction of 102 with [IrCl(COD)]2 and [RhCl(COD)]2. ... 

Highly stable diiridium complexes with tr/Tt-bridging disubstituted aryl ligands have been prepared by Muldoon and Brown via reaction of [Ir(cod)Cl]2 with 0.5 equiv. of Grignard reagents in The compounds, characterized... 

A particular class of iridium dimers with hydrides as both bridging and terminal ligands are the A-frame complexes described by Cowey and co-workers and already mentioned in several parts of this chapter. The reactivity of [Ir2H(CO)2(/U-H)2(dppm)2]BF4 1021 with different alkynes and alkenes has been reported and several diiridium complexes with bridging and terminal hydrides have been synthesized. The analogous heterodimetallic Rh/Ir species [RhIr(H)(CO)2(/U-H)2(dppm)2]OTf 318 has also been reported. 

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