87823-45-8Relevant articles and documents
Studies of 9-fluorenyl carbocations. Intramolecular hydride migration in a substituted 9-fluorenyl carbocation
Mladenova,Chen,Rodriquez,Siu,Johnston,Hopkinson,Lee-Ruff
, p. 1109 - 1114 (2001)
The substituted fluorenyl cation, 9-(diphenylmethyl)fluoren-9-yl cation (4), is formed under stable ion conditions (low temperature/strong acid) from its corresponding alcohol 3. This ion is transformed to a substituted diphenyl methyl cation 8 at ambient temperature via an apparent 1,2-hydrogen shift. Irradiation of 9-(diphenylmethyl)fluoren-9-ol in methanol gives products derived from the corresponding cation along with radical-derived products from C-C and C-O homolysis processes. The laser flash photolysis of this alcohol gave a transient corresponding to cation 4. All of the photoproducts are derived from cation 4 or radical pathways. High level MO calculations point to a high barrier (23.8 kcal mol-1) for the 1,2-hydride shift. This barrier is the consequence of the minimum energy conformation of this fluorenyl cation which is less than ideal for the periplanar geometry necessary for this process.
Reaction of stannenes and phosphastannenes with aldehydes and ketones: New tin four-membered ring derivatives
Kandri Rodi,Anselme,Ranaivonjatovo,Escudié
, p. 965 - 972 (2007/10/03)
Stannene Tip2Sn=CR2 1 (Tip = 2,4,6-triisopropylphenyl, CR2 = fluorenylidene) enters a [2+2] cycloaddition reaction with benzophenone to afford the four-membered ring derivative 2. This stannaoxetane undergoes a [2+2] decom
Substituent Effects on Electron Spin Distribution and Conformation of Radical Ions obtained from 9-Diphenylmethylenefluorenes
Franco, M. Luisa T. M. B.,Herold, Bernardo J.,Evans, Jeffrey C.,Rowlands, Christopher C.
, p. 443 - 450 (2007/10/02)
Nine new substituted 9-diphenylmethylenefluorenes were synthetized.The reductions of the unsubstituted hydrocarbon and eleven substituted derivatives were studied by cyclic voltammetry in dimethylformamide solution.E.s.r. and ENDOR spectra of the radical anions obtained by reduction with alkali metal in tetrahydrofuran were recorded.The electron spin distribution as obtained from experiment was compared with the results of Hueckel-McLachlan calculations.The conformations of the radical anions were determined from the spectra.The ratio of electron spin densities in the fluorene part of the alkene and in the diphenylmethylene group obeys a linear Hammett correlation.A similar study was performed for the radical cations of six of the twelve alkenes.