- Determination of thermodynamic affinities of various polar olefins as hydride, hydrogen atom, and electron acceptors in acetonitrile
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A series of 69 polar olefins with various typical structures (X) were synthesized and the thermodynamic affinities (defined in terms of the molar enthalpy changes or the standard redox potentials in this work) of the polar olefins obtaining hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the polar olefins (X ?-) obtaining protons and hydrogen atoms, and the thermodynamic affinities of the hydrogen adducts of the polar olefins (XH?) obtaining electrons in acetonitrile were determined using titration calorimetry and electrochemical methods. The pure Ci - 'C π-bond heterolytic and homolytic dissociation energies of the polar olefins (X) in acetonitrile and the pure Ci - 'C π-bond homolytic dissociation energies of the radical anions of the polar olefins (X?-) in acetonitrile were estimated. The remote substituent effects on the six thermodynamic affinities of the polar olefins and their related reaction intermediates were examined using the Hammett linear free-energy relationships; the results show that the Hammett linear free-energy relationships all hold in the six chemical and electrochemical processes. The information disclosed in this work could not only supply a gap of the chemical thermodynamics of olefins as one class of very important organic unsaturated compounds but also strongly promote the fast development of the chemistry and applications of olefins.
- Cao, Ying,Zhang, Song-Chen,Zhang, Min,Shen, Guang-Bin,Zhu, Xiao-Qing
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p. 7154 - 7168
(2013/08/23)
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- Reactions of 4-Chloro-9H-xanthene-9-thione with Tetrachloro-o-benzoquinone
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Thiones are usually converted to the corresponding ketones by oxidizing agents.Also high potential halogenated o-quinones oxidize thiones to the corresponding ketones.When 9H-thioxanthene-9-thione was subjected to the action of tetrachloro-o-benzoquinone the in presence of oxygen, it was oxidized to 9H-thioxanthen-9-one.Meanwhile tetrachloro- and tetrabromo-o-benzoquinones were found to react with diazoalkanes giving the corresponding cyclic acetals.
- Zeid, Ibrahim,El-Sakka, Ibrahim,Yassin, Salah,Abass, Atif
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p. 196 - 198
(2007/10/02)
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- C = C Double Bonds with Extreme Reactivity, III. Reactions of 9-(9-Fluorenylidene)xanthene
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According to equations (1) to (4), 9-(9-fluorenylidene)xanthene (2) reacts with sulfur, malonodinitrile, aniline, or thiophenol to give the compounds 3, 5, 7-11, and diphenyl disulfide.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner
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p. 3762 - 3765
(2007/10/02)
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- EXTREMELY REACTIVE CARBON-CARBON DOUBLE BONDS-I; REACTIONS WITH 2-(9-XANTHYLIDENE)-, 2-(9-THIOXANTHYLIDENE)-, AND 2-(9-FLUORENYLIDENE)-INDANE-1,3-DIONE. A CONTRIBUTION ON THE STRUCTURE AND REACTIVITY OF NON-PLANAR C-C DOUBLE BONDS
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The compounds in the title (cf 1a, 1b and 2) react with various reagents, often under mild conditions, mostly by breaking of the central double bond.According to X-ray diffraction the central double bond of 2-(9-xanthylidene)indane-1,3-dione is inclined by 47.2 deg.The relationship between the structure and reactivity of the compounds in the title is discussed.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner,Sheldrick, William S.
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p. 2429 - 2438
(2007/10/02)
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