- Intramolecular Binaphthyl Formation from Radical Cations of Tri-1-naphthyl Phosphate and Related Compounds in Photoinduced Electron-Transfer Reactions Sensitized by 9,10-Dicyanoanthracene
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The photoinduced electron transfer of tri-1-naphthyl phosphate and related compounds sensitized by 9,10-dicyanoanthracene (DCA) in acetonitrile produces 1,1′-binaphthyl and the corresponding biaryl. The quenching rate constant of the DCA fluorescence is calculated to be equal to the diffusion-controlled rate constant from the Stern-Volmer analysis and the fluorescence lifetime measurement. The free energy change calculated from the redox potentials and excitation energy of the singlet excited DCA indicates that the quenching process occurs exergonically to give the tri-1-naphthyl phosphate radical cation and DCA radical anion through electron transfer from tri1-naphthyl phosphate to the singlet excited DCA at the diffusion-controlled rate. On the basis of spectroscopic and kinetic studies with laser flash photolysis, pulse radiolysis, and γ-radiolysis, the radical cation of tri-1-naphthyl phosphate forms an intramolecular π-dimer radical cation with face-to-face interaction between the two naphthyl groups within 8 ns of the electron pulse. The 1,1′-binaphthyl radical cation is eliminated at the rate constant of kr = 5.3 × 105 s~: from the intramolecular π-dimer radical cation. Branching ratios of the reaction pathways are estimated for the reactive intermediates such as the tri-1-naphthyl phosphate radical cation and its intramolecular π-dimer radical cation from the rate constants and quantum yields. The electron-withdrawing character of the P(O) group in the O-P(O)-O spacer is responsible for the elimination of the binaphthyl radical cation. The DCA-sensitized photoinduced electron-transfer reaction of the tri-1-naphthyl phosphate is compared with the direct photoreaction.
- Nakamura, Mitsunobu,Dohno, Reizo,Majima, Tetsuro
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- Photoinduced electron-transfer reactions of tri-1-naphthyl phosphate and di-1-naphthyl methylphosphonate sensitised by 9,10-dicyanoanthracene
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1,1′-Binaphthyl is formed by photoinduced electron-transfer reactions of tri-1-naphthyl phosphate and di-1-naphthyl methylphosphonate sensitised by 9,10-dicyanoanthracene in MeCN, while no reaction occurs in the case of mono-1-naphthyl and di- or tri-phenyl esters.
- Nakamura, Mitsunobu,Dohno, Reizo,Majima, Tetsuro
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- 9,10-Dicyanoanthracene-photosensitized elimination of 1,1'-binaphthalene from dinaphthyl methylphosphonate and trinaphthyl phosphate through the termolecular interaction in the singlet excited state
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9,10-Dicyanoanthracene (DCA) photosensitized intramolecular binaphthalene elimination of dinaphthyl methylphosphonates and trinaphthyl phosphates occurred through an exciplex between the singlet excited DCA (1DCA*) and the naphthyl group of dinaphthyl methylphosphonate and trinaphthyl phosphates in tetrahydrofuran, 1,4-dioxane, and benzene. Diethyl mononaphthyl phosphates also formed an exciplex with 1DCA*, while no reaction occurred. The binaphthalene elimination occurs via the intramolecular quenching of the exciplex by the second naphthyl group of dinaphthyl methylphosphonate or trinaphthyl phosphate, while the exciplex between the mononaphthyl phosphate and 1DCA* decays to give the starting compounds. The lifetime of the exciplex between the trinaphthyl phosphate and 1DCA* was shorter than that between the mononaphthyl phosphate and 1DCA*. The termolecular interaction (teraromatic groups interaction) of 1DCA* and two naphthyl groups of dinaphthyl methylphosphonate or trinaphthyl phosphate is suggested by the emission observation of the termolecular interaction of two naphthyl groups of trinaphthyl phosphate and 1,4-dicyanobenzene in the singlet excited state during the quenching of the intramolecular excimer of dinaphthyl methylphosphonate or trinaphthyl phosphates by 1,4-dicyanobenzene. The O-P(O)-O spacer is necessary for the binaphthalene elimination during the termolecular interaction in the singlet excited state.
- Nakamura, Mitsunobu,Miki, Masamichi,Majima, Tetsuro
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- Novel photolabile protecting group for phosphate compounds
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A novel photolabile protecting group, thiochromone S,S-dioxide, containing the diazomethyl group for protection of phosphate derivatives is described. Deprotection of the successfully protected phosphate derivatives proceeded smoothly under photoirradiation using an ultrahigh-pressure mercury lamp to recover the corresponding phosphates quantitatively, and the photoproduct derived from the thiochromone derivative showed high fluorescence intensity. Georg Thieme Verlag Stuttgart · New York.
- Zhang, Youlai,Tanimoto, Hiroki,Nishiyama, Yasuhiro,Morimoto, Tsumoru,Kakiuchi, Kiyomi
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scheme or table
p. 367 - 370
(2012/03/11)
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- Small ligands interacting with the phosphotyrosine binding pocket of the Src SH2 protein
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Various small fragments bearing phosphate, phosphonate or phosphonic acid moieties have been prepared through parallel synthesis and their binding potencies evaluated on the Src SH2 protein using a BIAcore assay. This provided us insight into the requirement of the Src SH2 pTyr binding pocket and some promising small ligands have been characterised.
- Deprez, Pierre,Mandine, Eliane,Gofflo, Dominique,Meunier, Stephane,Lesuisse, Dominique
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p. 1295 - 1298
(2007/10/03)
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- PHOTOCHEMICAL REACTIONS OF TRI-1-NAPHTHYL AND TRIS(8-QUINOLYL) PHOSPHATES
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Upon UV-irradiation in alcohol, tri-1-naphthyl phosphate give 1-naphthyl 1,2'-binaphthalene-1'-yl phosphate and 1,1'-binaphthalene through intramolecular processes.Under the same conditions, tris(8-quinolyl) phosphate give alkyl phosphates by photo-alcoholysis, but in acetonitrile furadiquinoline was given.The reaction mechanisms was investigated by means of quenching experiments for fluorescence spectra and products by oxygen. - Key words: Tri-1-naphthyl phosphate; tris(8-quinolyl) phosphate; reaction mechanism; fluorescence spectra; UV spectra
- Nakamura, Mitsunobu,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 137 - 144
(2007/10/03)
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- Layered vanadium compounds containing phosphorus or arsenic and pendant organic groups
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A layered oxide containing vanadium together with phosphorus or arsenic and an organic group may be prepared which has a unique layered structure of the formula: VORAO3.nS or VOROAO3.nS where A is phosphorus or arsenic, S is a solvent molecule, R is an unsubstituted or alkyl-, alkoxy- or aryl-substituted alkyl or aryl group, and n is zero or a positive number. These layered compounds are characterized in that the vanadium is substantially in a 4+ oxidation state and is present in an amount such that the molar ratio of A:V ranges from 0.8 to 1.2 throughout the oxide. Also the R groups are covalently bound to an A atom in the vanadium oxide layer directly through either carbon or oxygen atoms.
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