Coupling constants sulfides

What are available of proton and carbon data for compounds containing the 1,2,2,2-tetrafluoroethyl group are given in Scheme 6.7. Note that the vicinal F—H coupling constants for the sulfides are much greater than those of the analogous ethers. 

Table 21. Solvent dependence of coupling constants in styrene oxide, styrene sulfide and 2,2-dichlorocyclopropylbenzene...

NMR has also been used as a basis for distinguishing 1- and 2-acetyl-triazoles - - and for investigating ring-chain tautomerism in tri-azoles. - - 0-H coupling constants are a useful means of determining the site of methylation of triazolo oxides, and triazolo sulfides. -... 

Oxidation of a snlfide to sulfoxide is known to be an electrophilic reaction, in contrast with nncleophUic oxidation of sulfoxide to sulfone. Since 2-nitrobenzenesulfinyl chloride/KOi oxidizes sulfides to sulfoxides selectively, intermediate 48 must be the actual active intermediate. Moreover, in the presence of l,4-diazabicyclo[2.2.2.]octane (DABCO), which is a radical capturing reagent, the oxidation of methyl phenyl sulfide to the sulfoxide was inhibited. In order to further detect the intermediate 48, pure 5,5-dimethyl-l-pyrroUne-l-oxide (DMPO) was used as a trapping reagent and spin adduct was obtained. The ESR spectrum of the DMPO spin adduct was obtained by the reaction of 02 with 2-nitrobenzenesulfinyl chloride (hyperfine coupling constants, aH = 10.0 G and aN = 12.8 G). 

The diagnostic coupling constant /P c for conformational analysis of phosphorinanes (P-CN = 3) is lost with phosphorinanes where P-CN = 4. Shifts and /P c values of two non-rigid and two cis-trans rigid phosphorinane 1-oxides and 1-sulfides should be studied for comparison (Tables 2 and 3). The large differences between the two classes are then evident. 

The 1,1,2,2-tetrafluoroethyl group, usually appearing as either the ether or the sulfide, is quite commonly encountered, probably because of its relative ease of synthesis from nucleophilic additions to tetrafluo-roethylene. The fluorine NMR spectra of such isolated tetrafluoroethyl groups are characterized by the usual large (54 Hz) two-bond H-F coupling constant (Scheme 6.5). 

Complete NMR spectral assignments have been made for the trans,cis and transjrans spiroepoxides derived by epoxidation of (Z)-3-arylidenethioflavanones, their 1-oxides and 1,1-dioxides (Table 7). As a consequence of the similarity of the chemical shifts of the signals in the 13C NMR spectra of the isomer pairs, coupling constants data for 37n-2,c-8a (37hc 7.0-7.6 Hz sulfide Vhc 6.2-6.5 Hz sulfoxide Vhc 2.0-3.4 Hz sulfone) and NOESY experiments were used extensively together with ab initio MO calculations to elucidate the conformation of the various isomers <2001MRC251, 2003MRC193>. 

The phosphorus oxide sulfide P403S6 has been described by G. U. Wolf and M. Meisel (178) shows an A3X-type 31P NMR spectrum with signals at +46.0 ppm [P(III)] and + 55.7 ppm [P(V)], the coupling constant being 108 Hz. This corresponds to the molecular structure described in Section III.B. 

The P NMR spectra of the remaining phosphorus oxide sulfides were recorded using solutions that in most cases contained mixtures of these compounds (77). The chemical shifts and coupling constants... 

SD and PSO interactions. Galasso et al carried out calculations of /(C, H), V(H, H), and /(H, H) in a representative series of thiono-, oxo thiono-, dioxo-, and dithiono- derivatives of sparteine. A satisfactory reproduction of SSCCs were obtained. Heydenreich et al calculated /(C, H) via a sulfur atom in two series of compounds, both including a sulfide, a sulfoxide, and a sulfone. The calculation including only the FC term was found to be sufficient for the correct estimation of /(C, H) coupling constants, because the other non-contact contributions were small. 

Chemical Shifts and Coupling Constants of Cyclic Sulfides... 

Chemical Shifts and Coupling Constants of Cyclic Sulfides (d in ppm, J in Hz)... 

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