- Ring inversion dynamics of derivatives of thianthrene di- and tetraoxide
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The ring inversion barrier for thianthrene tetraoxide was determined by making use of the variable temperature 13C NMR spectra of the 2,7-diisopropyl derivative (ΔG? = 6.5 kcal mol-1). The barrier is lower than that measured for a trans thianthrene dioxide derivative (ΔG? = 9.35 kcal mol-1). These results agree well with ab initio theoretical predictions.
- Casarini, Daniele,Coluccini, Carmine,Lunazzi, Lodovico,Mazzanti, Andrea
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Read Online
- Oxidative coupling of diaryldisulfides by MoCl5 to thianthrenes
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"Chemical Equation Presented" Oxidative C-S coupling: The oxidative coupling reaction of 1,2-diaryldisulfides by using MoCl5 or mixtures thereof with TiCl4 gives fast and efficient access to dibenzo[b,e] [1,4]dithiins such as that depicted (thianthrenes).
- Spurg, Anke,Schnakenburg, Gregor,Waldvogel, Siegfried R.
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experimental part
p. 13313-13317+13274
(2010/06/15)
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- RADIKALIONEN 89. EINELEKTRONEN-OXIDATIONEN VON DIARYLDISULFIDEN MIT AlCl3/H2CCl2
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The single electron oxidation of 14 alkyl and alkoxy substituted diaryldisulfides by AlCl3/H2CCl2 has been investigated by ESR/ENDOR spectroscopy.The radical cations observed prove the following skeletal rearrangements: Those with ring hydrogens in ortho positions to the disulfide bridge preferentially form thianthrene derivatives.The isomeric dinaphthyl disulfides react differently, the 2,2'-isomer yielding the dibenzothianthrene radical cation and the 1,1'-isomer the well-known naphthalene-1,8-disulfide radical cation.For all diaryl disulfides with completely alkyl- or methoxy-blocked ortho positions, oxidative desulfuration is observed.As substantiated by additional (2)D and (33)S isotope marking, the bis(2,5-dimethoxyphenyl)disulfide reacts both to the corresponding thianthrene derivative as well as via desulfuration to the radical cation of the monosulfide.Accompanying cyclovoltammetric and photoelectron spectroscopic measurements prove that all ESR spectroscopically detected radical cations result from compounds Ar-S-Ar, Ar-SS-Ar and Ar(S)2Ar with rather low oxidation or ionisation potentials and thus suggest that each the most easily oxidized paramagnetic species is observed in the rather complex product mixtures, which form on AlCl3/H2CCl2 oxidation of diaryldisulfides. Key words: Diaryl disulfides; one-electron oxidation; radical cations; ESR/ENDOR spectra.
- Bock, Hans,Rittmeyer, Peter
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p. 261 - 292
(2007/10/02)
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- Radical Ions, 51. Oxidative Rearrangement of Diphenyl Disulfides to Thianthrenes
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para-Substituted diphenyl disulfides 1 - 5 with low gas phase ionization energies of about 8 eV react with AlCl3 in CH2Cl2 to form radical cations of the corresponding thianthrenes (Table 2, Figure 2).Warming of these solutions produced a second ESR signal which is attributed to a benzodithiete radical cation (Table 2, Figure 3).This is possibly the reactive intermediate in the S8 or S2Cl2 catalyzed Friedel-Crafts chlorination of benzene.
- Giordan, Judith,Bock, Hans
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p. 2548 - 2559
(2007/10/02)
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