Kinetics of thermal decomposition of sulfur-containing amino acids

Affecting an Ultra‐High Work Function of Silver

“…This very significant lowering reflects the known catalytic effect of silver on thermal degradation, which has been observed previously in other organically doping silver [35,36] and is adirect proof of the entrapment of cysteine. Thebroadening of the peaks in the doped form is areflection of am ore heterogeneous environment that the dopant molecules experience,t hat is,o ft he various cage and pore geometries where the dopant molecules resides.T he main gaseous products of the thermal decomposition of pure cysteine are H 2 Sa nd CO 2 ,o btained by the cleavage of C À C and C À Sb onds, [37] are shown in Figure 4C,D.I nterestingly, the presence of Zn II strongly influences the decomposition behavior of cysteine compared with entrapment in pure silver, indicating as trong interaction between them. Firstly,t he catalytic effect of silver has been attenuated in presence of zinc, as the decomposition of cysteine occurs at higher temperature;a nd second, there appears ap eak at the elevated temperature of 550 8 8C( Figure 4A), which is associated with CO 2 ,asshown by the MS-coupled to the TGA of cys/Zn II @Ag ( Figure 4C).…”

The enthalpy of formation of methionine revisited

“…We additionally note that the thermal decomposition process of methionine is complicated, i.e. produces numerous species, and so even at the “low” temperatures of Sabbah and Minadakis’ experiments, these results may also be problematic …”

“…produces numerous species, and so even at the "low" temperatures of Sabbah and Minadakis' experiments, these results may also be problematic. [10][11][12] Sabbah and Minadakis [4] report three values for the enthalpy of sublimation in the temperature interval from 417 to 425 K. A mean value of 140.5 kJÁmol -1 at T = 421 K is calculated. Adjustment to T = 298.15 K resulted in a sublimation enthalpy of (164 AE 4) kJÁmol -1 .…”

Psychotriadouarrei and Geissois pruinosa, novel resources for the plant-based catalytic chemistry

“…Therefore it was interesting to examine whether the sulfate derived from P. douarrei was the result of the sulfur amino acid decomposition during the thermic treatment, which could explain the abnormal high level of sulfates. It had been 95 reported that cysteine, methionine, glutathione and proteins are thermally decomposed, at 400°C, in various gases such as H 2 O, H 2 S, CO 2 , NO 2 , SO 2 , and N 2 O 3 [16,17]. That is why we concluded that the excessive amount of sulfate measured was not a consequence of an unusual sulfur amino acid contained in the 100 plant.…”