- How to Manipulate Through-Space Conjugation and Clusteroluminescence of Simple AIEgens with Isolated Phenyl Rings
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Apart from the traditional through-bond conjugation (TBC), through-space conjugation (TSC) is gradually proved as another important interaction in photophysical processes, especially for the recent observation of clusteroluminescence from nonconjugated mo
- Hu, Lianrui,Lam, Jacky W. Y.,Li, Xingguang,Liu, Junkai,Sung, Herman H. Y.,Tang, Ben Zhong,Wang, Haoran,Wang, Zhaoyu,Williams, Ian D.,Zeng, Zebing,Zhang, Haoke,Zhang, Jianyu,Zhang, Kaihua
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supporting information
p. 9565 - 9574
(2021/07/01)
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- Fluorocarbanion chemistry. Tris(4-nitro-2,3,5,6-tetrafluorophenyl) methane and companions
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The titled compound (2) is prepared by oxidation of tris(4-amino-2,3,5,6-tetrafluorophenyl) methane with 98% H2O2 and trifluoroacetic anhydride. Compound 2, a strong carbon acid, forms long-persisting deep blue solutions of the anion
- Filler, Robert,Fiebig Jr., August E.,Mandal, Braja K.
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p. 185 - 188
(2007/10/03)
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- Ionisation of Nitrotriphenylmethanes. Remarkable Kinetic Evidence of steric Inhibition to Resonance and F-strain
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Rate and equilibrium data for the reversible deprotonation of 2,2',2'',4,4',4''-hexanitro-, 2,2',4,4',4''-pentanitro-, 2,4,4',4''-tetranitro-, 4,4',4''-trinitro-, 4,4'-dinitro- and 4-nitro-triphenylmethanes (2a-f) by hydroxide ion have been measured in various H2O-dimethyl sulphoxide (DMSO) mixtures at 25 deg C.The increase in acidity (pKa) brought about by the indroduction of a first p-nitro group in triphenylmethane (2g) to give 2f is very large and equal to about 12 pK units while the acid-strengthening influence of each of the second and third p-nitro groups isonly of the order of 2 pK units.This suggests that only one p-nitrophenyl ring of the 4,4'-dinitro- and 4,4',4''-trinitrotriphenylmethyl anions is in a favourable position for effective conjugation with the exocyclic sp2 carbon atom of these carbanions at any given time.Accordingly, the effects exerted by the additional p-nitrophenyl ring(s) are mainly inductive in nature.Support for these ideas is the observation that the increases in acidity observed in going from (2f) to (2e) to (2d) are essentially the result of the corresponding increases in the kinetic acidity (kOHp).Addition of a first o-nitro group to (2d) to form (2c) further increases the kinetic acidity but it also results in a large decrease in kH2O-p, consistent with the preferential stabilization of the corresponding 2,4,4',4''-tetranitrotriphenylmethyl carbanion (C-2c) by the 2,4-dinitrophenyl ring.Significantly the introduction of the second and third o-nitro groups enhances the thermodynamic acidity while it decreases markedly the kOHp and kH2O-p values.It is suggested that these anomalous variations are the reflection ofunfavourable steric interactions arising from the accumulation of o-nitro groups in the triphenylmethane system.
- Terrier, Francois,Xie, Hai-Qi,Lelievre, Jacques,Boubaker, Taoufik,Farrell, Patrick G.
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p. 1899 - 1903
(2007/10/02)
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- Photolysis of Triphenylmethylphosphonic Acid and its Dimethyl Esters: A Novel Photochemical Generation of Dimethoxyphosphinyl(phenyl)carbene by α,α-Elimination of Phenyl Groups
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Photolysis of triphenylmethylphosphonic acid and its dimethyl ester in ethanol gave biphenyl and a product derived from dimethoxyphosphinyl(phenyl)carbene.
- Min, Shi,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 151 - 153
(2007/10/02)
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- Solvent Dependence of the Ionization of Nitrophenylmethanes
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The solvent dependence of proton abstraction from various nitrophenylmethanes has been examined for aqueous dimethyl sulphoxide and methanolic dimethyl sulphoxide solutions.Even though the compounds studied vary considerably in thermodynamic acidity (pKa), their proton-abstraction rates all show the same solvent dependence.It is suggested that the transition states for these reactions all occur at similar positions on the reaction pathway, and that transition state imbalances exist for these proton transfers.
- Fogel, Paula,Farrel, Patrick G.,Lelievre, Jacques,Chatrousse, Alain P.,Terrier, Francois
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p. 711 - 716
(2007/10/02)
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