Iridium complex compounds trans

I 14 Tran omations of (Organo)silicon Compounds Catalyzed by Iridium Complexes... 

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 student may well feel that the need to name inorganic compounds is a relic of the past, when stoichiometric formulae were often uncertain, and that a formula will convey a more concise specification of a substance. This attitude is not without merit, especially where we are dealing with rather complex substances whose systematic names are hopelessly clumsy and lengthy. For example, the important substance rendered as IrCl(CO)(PPh3)2 on the printed page has the systematic name trans-chlorocarbonylbis(triphenylphosphine)iridium(I). Although hundreds of papers have been published on the reactions of this compound and tens of thousands of students have heard of it, the systematic name is rarely used. In speech, and often in print, it is given the trivial name Vaska s compound . In any research laboratory, you may hear talk of Judy s compound , or Ralph s anion . 

The preparation of bis(bipyridyl) (702) and bis(phenanthroline) cobalt(III) complexes (576) has been the subject of a number of papers. Interest centers on the possibility of cis-trans isomerism in these complexes, since it would seem that the close approach of the 6,6 -(bipyridyl) and 2,9-(phenanthroline) protons in the trans complex would make this stereochemistry unattractive for central ions such as co-balt(III), rhodium(III), or iridium(III). Cis complexes are well established, but a violet compound claimed to be anionic cobalt(II) species (21, 573, 591). 

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