Hydrogen sulfide protonated

The process implications of equation 3 go beyond the weU-known properties (27—29) of NMP to faciUtate S Ar processes. The function of the aminocarboxylate is also to help solubilize the sulfur source anhydrous sodium sulfide and anhydrous sodium hydrogen sulfide are virtually insoluble in NMP (26). It also provides a necessary proton acceptor to convert thiophenol intermediates into more nucleophilic thiophenoxides. A block diagram for the Phillips low molecular weight linear PPS process is shown in Eigure 1. 

In water solution, hydrogen sulfide acts as a Brensted-Lowry add it can donate a proton to a water molecule ... 

The thiophene ring is opened and sulfur extruded as hydrogen sulfide when 3,4-dinitrothiophene is reacted with piperidine. The product contains two nitroenamine units coupled to each other (Scheme 140). Other secondary amines react similarly (69CC549). Secondary aliphatic amines also react with 2-nitrothiophene to form the nitrodienamines (426) in 50-80% yield. It is believed that the reaction involves addition of the amine at position 5, followed by proton transfer and ring opening to give the thiol which, in the presence of air, oxidatively dimerizes to (426) (Scheme 141). In one case the thiol has been trapped as the silver salt and methylated (74JCS(P1)2357). 

The oxygen and sulfur bases are weaker than the nitrogen bases, and accurate solution basicities are not available. Arnett s heat of protonation studies indicate that the order of decreasing basicity is ROR > ROH > HaO,98 a result that is in agreement with gas-phase measurements.99 Hydrogen sulfide in the gas phase has basicity comparable to that of water (Table 3.18), and substitution of H by alkyl produces stronger gas-phase bases just as does similar substitution on oxygen. 

Protonated di-terf-butyl sulfide 61 shows very little cleavage at 60°C. At —35°C it cleaves slowly (f1/2 - 1 h) to tot-butyl cation and protonated hydrogen sulfide [Eq. (4.40)], with the latter showing the H NMR peak at 81H 6.60. 

Oxidation of H>S by (X Hydrogen sulfide (H /HS-) is rapidly oxidized in aqueous solution by 03 even in its protonated form (80,81). The rate expression can be written as ... 

Hydrogen bonding, 16, 110,122 Hydrogen electrode, 234 Hydrogen ion, 22-24 See Proton Hydrogen sulfide, 437 Hydrolysis, 69, 75 Metal-ions, 75-76... 

The Eh values are too high to be explained by the formation of either PtS or PtS2. The rest potentials of the platinum electrode are dependent upon the concentration of dissolved hydrogen sulfide (z[H2S]]. This can be explained by selective adsorption of H2S species on the platinum followed by the discharge of the proton mediated via chemisorbed H2S. The corresponding reactions are (11] ... 

Hiraoka, K., and Kebarle, R, Gas phase ion equilibrium studies of the proton in hydrogen sulfide and hydrogen sulfide—water mixtures. Stabilities of the hydrogen bonded complexes ... 

Aminophosphines can react with protonic acids (HX) to form P—H bonds. Generally, such reactions produce NH and PX products, owing to the polarity of the P—N bond . Hydrogen sulfide and dialkylaminodialkylphosphines in benzene at 80°C yield dialkylphosphine sulfides quantitatively ... 

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