large negative Hammett ρ-value (ρ = −1.76 in water; −1.85 in CH3CN/H2O(1/4, v/v); −2.35 in TFE/H2O (1/1, v/v)), relatively large m-values (ca. 0.83 for fluoro(diphenyl)-λ6-sulfanenitrile; ca. 0.82 for fluoro(p-nitrophenyl)(phenyl)-λ6-sulfanenitrile against the solvent ionizing power YOTs-values in acetonitrile–water), a common ion effect in TFE/H2O, and a small salt effect. The large negative activation
Reaction of S,S-diaryl-S-fluorothiazynes6) with cyclic secondary amines gave novel thiazynes, the corresponding S-aminothiazynes in good yields. Spectroscopic studies, measurement of pKa values, pyrolysis and alkylation reactions of the aminothiazynes were carried out.
S,S-Diaryl-S-fluorothiazynes, Ar2SF(≡N), were prepared by the reaction of S,S-diaryl-N-bromosulfilimines with tetrabutylammonium fluoride. The thiazyne structure was assigned by the spectral data, physical properties, and is consistent with reactions with sodium alkoxides and primary amines. The thiazyne prepared previously by Clifford et al. is doubtful.
The reaction of fluorodiphenyl-λ6-sulfanenitrile with primary alkyl- or aryl-amines in the presence of acid catalysts or tertiary amines gave N-monosubstituted S,S-diphenylsulfodiimides effectively.
μ-aza-bis[diphenyl(imido)sulfur(V)] perchlorate (4) and μ-aza-[diphenyl(imido)]-[diphenyl(oxo)]disulfur(V) perchlorate (5) ([Ph2XSNSPh2NH]+[ClO4]−, X=NH, O). The crystal structures of 4 and 5 were determined by X-ray crystallographic analysis. The former has essentially C2 symmetry with an SNS bondangle of 120.3(2)°, bridging SN bondlengths of 1.595(3) and 1.604(3) Å, and terminal SN bond lengths