2177-48-2Relevant articles and documents
1,3-disubstituted indene complexes
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, (2008/06/13)
The present invention relates to organometallic compounds of transition metals with an indenyl ligand bonded in the 2-position and substituted in the 1,3-position, a process for their production, and their use as catalysts for the (co)polymerization of ol
Photochemistry of Alkylindenes in the Gas Phase
Suarez, Marie L.,Duguid, Robert J.,Morrison, Harry
, p. 6384 - 6391 (2007/10/02)
The photochemistry of indene and several alkylindenes has been studied in the gas phase using excitation (254 nm) which populates the S2 state.Reactions observed in the gas phase involve rearrangements different from those observed in solution, as evidenced by the formation of photoproducts explicable in terms of net hydrogen and alkyl migrations.Photodealkylation is also observed at low pressures.In a typical example, gas-phase irradiation of 1-methylindene produces 3-methylindene as the major product, in addition to 2-methylindene, while irradiation in solution leads only to the 2-methyl isomer.The reaction mechanism has been investigated via deuterium-labeling studies, the use of added potential triplet sensitizer and quencher gases, and collisional deactivation by added inert gases.Irradiation of selectively deuterated indenes results in nearly statistical scrambling in the five-membered ring of the indene skeleton, and multiple 1,5 hydrogen or alkyl migrations are proposed.The lack of triplet sensitization, quenching, or enhancement indicates that the photochemistry is derived from a single state.Collisional deactivation results in net quenching of all the photoproducts, with those exclusive to the gas phase quenched at a faster rate than the products observed in solution.Collisional deactivation concomitantly results in an enhancement in fluorescence emission, with little emission observed upon excitation into S2 in the absence of a quencher gas.A reaction scheme is proposed which involves the generation of photoproducts from S2 and S1vib.
Photoinduced Skeletal Rearrangement of Alkylindenes
Morrison, Harry,Giacherio, David,Palensky, Frederick J.
, p. 1051 - 1058 (2007/10/02)
The indene phototransposition reaction, a skeletal rearrangement of certain alkylindenes involving an interchange of carbons 1 and 1 (eq 2), is described.The postulated mechnism (Scheme II) involves a closure followed by a sigmatropic shift, opening to an isoindene and 1,5 hydrogen shifts to re-form the indene system.Results of experiments with indenes containing different alkyl groups at C1 and C2 and with 1,1-dimethylindene lend support to the proposed scheme.Experiments with (+)-1,2-dimethylindene indicate that the net migration of C1 to C3,necessary for transposition, occurs with clean inversion at C1 (as would be expected for a ground-state, four-electron, electrocyclic reaction).The reaction derives from the excited singlet state, and partial movement along the initial reaction surface appears to provide an efficient path for S1 radiationless decay.
