Synthesis and C-H activation reactions of ({eta}{sup 5}-indenyl)(trimethylphosphine)iridium alkyl and hydride complexes

Journal Article · Fri May 01 00:00:00 EDT 1992 · Organometallics

DOI:https://doi.org/10.1021/om00041a013· OSTI ID:552720

Foo, T; Bergman, R G ^[1]

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1. Univ. of California, Berkeley, CA (United States)

To obtain C-H oxidative addition products susceptible to further chemical transformation, the synthesis of a series of indenyliridium complexes that parallel the pentamethylcyclopentadienyl systems shown earlier to successfully activate alkane carbon-hydrogen bonds has been developed. Efficient routes to several members of the series ({eta}{sup 5}-C{sub 9}H{sub 7})IR(PMe{sub 3})(X)(Y), where X and Y are alkyl, aryl, and hydride ligands, are described. The structure of the (methyl)(phenyl)iridium complex (n{sup 5}-C{sub 9}H{sub 7})Ir(PMe{sub 3})(CH{sub 3})(Ph) (4b) has been determined by X-ray diffraction: space group P2{sub 1}/c with a = 7.6688 (6) {Angstrom}, b = 18.5650 (16) {Angstrom}, c = 12, 3855 (9) {Angstrom}, {alpha} = 90.0{degrees}, {beta} = 98.674 (7){degrees}, {gamma} = 90.0{degrees}, and Z = 4; R = 0.0164; R{sub w} = 0.0223 on the basis of 1972 data having F{sub 0}{sup 2}> 3{sigma}(F{sub o}{sup 2}). In spite of the increased lability of these complexes caused by the presence of the indenyl ligand, they retain both the thermal and photochemical C-H activating properties associated with the corresponding pentamethylcyclopentadienyl complexes. Thus ({eta}{sup 5}-C{sub 9}H{sub 7})Ir(PMe{sub 3})H{sub 2} (7) undergoes loss of H{sub 2} on irradiation and in benzene and cyclohexane solvent leads to ({eta}{sup 5}-C{sub 9}H{sub 7})Ir(PMe{sub 3})(C{sub 6}H{sub 5})(H) (6b) and ({eta}{sup 5}-C{sub 9}H{sub 7})Ir(PMe{sub 3})(C{sub 6}H{sub 11})(H) (6d), respectively. Thermolysis of ({eta}{sup 5}-C{sub 9}H{sub 7})Ir(PMe{sub 3})(CH{sub 3})(H) (6a) occurs to eliminate methane at a temperature lower than that for the Cp* analogue and in benzene and cyclohexane once again leads successfully to the phenyl and cyclohexyl hydrides 6b and 6d. 27 refs., 1 fig., 2 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 552720
• Journal Information: Organometallics, Journal Name: Organometallics Journal Issue: 5 Vol. 11; ISSN 0276-7333; ISSN ORGND7
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ALKANES
ALKYL RADICALS
BENZENE
CARBON
CHEMICAL ACTIVATION
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
CYCLOHEXANE
HYDRIDES
HYDROGEN
INFRARED SPECTRA
IRIDIUM COMPLEXES
IRRADIATION
LIGANDS
METHANE
MOLECULAR STRUCTURE
NMR SPECTRA
PHOTOCHEMICAL REACTIONS
QUANTITATIVE CHEMICAL ANALYSIS
SYNTHESIS
THERMODYNAMIC PROPERTIES
X-RAY DIFFRACTION