Pentamethylcyclopentadienyl iridium dichloride dimer
|Molar mass||796.71 g/mol|
|Melting point||>230 °C|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Pentamethylcyclopentadienyl iridium dichloride is an organometallic compound with the formula [(C5(CH3)5IrCl2)]2, commonly abbreviated [Cp*IrCl2]2 This bright orange air-stable diamagnetic solid is a reagent in organometallic chemistry.
Preparation, structure, reactions
The compound has C2h symmetry. Each metal is pseudo-octahedral. It was first prepared by the reaction of hydrated iridium trichloride with hexamethyl dewar benzene. More conveniently, iridium trihydrate and pentamethylcyclopentadiene consistently gives the product in both high yield and purity according to this idealized equation:
- 2 Cp*H + 2 IrCl3(H2O)3 → [Cp*IrCl2]2 + 2 HCl + 6 H2O
The two Ir-μ-Cl bonds are labile and can be cleaved to give a variety of adducts of the general formula Cp*IrCl2L. Such adducts undergo further substitution to afford cations [Cp*IrClL2]+ and [Cp*IrL3]2+. The chloride ligands can also be replaced by other anions such as carboxylates, nitrite, and azide.
Reduction of [Cp*IrCl2]2 under an atmosphere of CO affords the dicarbonyl Cp*Ir(CO)2], which can be decarbonylated to give the unsaturated derivative [Cp*Ir(CO)]2. Treatment of [Cp*IrCl2]2 with borohydride under an atmosphere of H2 gives the iridium(V) derivative Cp*IrH4.
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