A hydrido diolefin complex of iridium(III)

TetrahedronLettersN0.20,p. 1301, 1964. PergamonPress Ltd. Printedin GreatBritain,

A BTDRIDODIOLEFIECOMPLEXOF IEI;IIDW(III) By S. D. Robinsonand B. L. Sbaw Departmentof Inorganicand StructuralChemistry, .Thhe university, Leeds 2. (Received2 April 1964) Complexescontaininghydrogenand an olefinbondedto the same metal atoms have been postulatedas unstableintermediates in variouecatalytic reactionse.g. CXO syntheses(l), but have not hithertobeen prepared. We now describea hydridocycle-octa-1,5-diene complexof iridium(II1) CI~c12(C#,2)12 PrePared in 70% yield by heatingan ethanolsolutionof chloroiridic acid with cycle-octa-1,5-diene for 2 hr.

It forms insoluble

cream microcrystals decomposing>2CO" withoutmelting. The infrared Sp3CtrWiI

Shows

a strongabsorptionband at 2261 CBA.-"due to aniridium-

-hydrogenstretchingmode, this shiftson deuterationto 1613 cm".

&l

treatmentwith diethylhenylphosphine this hydridocomplexgives the hydride complex[IrBC12(PEt2Fh)3] (whiteisomer)(2).

With sodium carbonatein

methanolthe methoxylbridgediridium(I)complex[Ir(OCB3)(C#,2)]2 ia formed, this reactionis reversedby hydrochloric acid.

Treatmentof [IrBC12(C$i,2)]2

with cyclopentadienylsodium give8 the volatilecyclopentadienyl iridium(I) and with thallousacetylacetonate the acetylacetonatocomplexCIr(C5H5)(CgH,2)1 iridium(I)complex LIr(acac)(C$i,2)j. Furtherstudiesof olefin-iridium complexesare in progress.

1.

Sternbcrgand Wender,FifthInternational Conferenceon Co-ordination No. 13. p. 51. Chemistry,London,1959. ChemictiSocietySpecialPublication

7.

Chatt sod Shaw,Chemistryand Industry.931(1963).

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