Iridium complexes, with nitrogen

Coordination Compounds. A large number of iridium complexes with nitrogen ligands have been isolated, particularly where Ir is in the +3 oxidation state. Examples of ammine complexes include [Ir(NH3)6]3+ [24669-15-6], [IrCl(NH3)]2+ [295894)9-1], and trans-[Ir(03SCF3)2(en)2]+ [90065-94 4]. Compounds of IV-heterocyclic ligands include trans- [IrCl4(py)2] [24952-67-8], [Ir(bipy)3]3+ [16788-86-6], and an unusual C-metalated bipyridine complex, [Ir(bipy)2(C3,N-bipy)]2+ [87137-18-6]. Isolation of this latter complex produced some confusion regarding the chemical and physical properties of Pi(bipy)3]3+ (167). 

The reaction of an iridium complex with furanoyl azide seems to involve coordination of the terminal nitrogen with the iridium, followed by dissociation to a stable iridium-nitrogen complex and furanoyl isocyanate (which incorporates a carbonyl that had been part of the iridium complex). 

Some platinum metals, especially ruthenium but also rhenium, osmium, and iridium, form luminescent complexes with nitrogen-containing ligands, e.g., 2,2 -bipyridine (bpy). These complexes may participate in redox reactions with concomitant chemiluminescence in three different ways. 

Alkylation of sp3 C-H bonds adjacent to a heteroatom such as nitrogen and oxygen is possible. The early works using tungsten or iridium complexes involved the reaction of dimethylamine with 1-pentene (Equation (29)) and the alkylation of a C-H bond adjacent to oxygen with / r/-butylethylene.34,34a,34b... 

The [Ir CMeatpa) ethene)] " " complex also reacts with nitrogen monoxide, leading to the formation of [Ir(Me3tpa)(NO)]. Nitrogen monoxide binds to the iridium center in a linear fashion, as indicated by the X-ray structure determination and an absorption frequency of v= 1800 cm in the IR spectrum. The [lr(Me3tpa)(NO+)] + complex can also be prepared by treatment of [Ir (Me3tpa) (ethene)]+ with [NO]+[PF6] . 

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