The effects of l-cysteine on the inhibition and accelerated dissolution processes of zinc metal

Affecting an Ultra‐High Work Function of Silver

“…but as we shall see below,t he addition of cysteine,q uenches this reaction, probably through the protective interaction of cysteine with Zn(OH) 2 : [21] Cys-SH þ…”

“…At the used low concentrations of cysteine, it is not blocking the Zn from reducing the Ag + . Thus, while Gibbs free energy of metallic zinc‐cysteine formation is −25 kJ mol −1 , the free energy of the reduction of Ag + by zinc is −308 kJ mol −1 …”

“…504 cm −1 is associated with an S−S dipeptide bond pointing to the existence of cystine (the oxidized dimer of cysteine), which again is relevant to the zinc‐finger phenomenon discussed below. Notably, Shkirskiy et al . reported that in the Zn oxide‐hydroxide film/cysteine system, the value of the Gibbs free energy of the complex formation between these two components is −100 kJ mol −1 , that is, the formation of Zn(cys) 2 is thermodynamically favored over simple adsorption, for which, G 0 was about −25 kJ mol −1 .…”

“…504 cm À1 is associated with an S À Sd ipeptide bond pointing to the existence of cystine (the oxidized dimer of cysteine), which again is relevant to the zinc-finger phenomenon discussed below. Notably,S hkirskiy et al [21] reported that in the Zn oxidehydroxide film/cysteine system, the value of the Gibbs free energy of the complex formation between these two components is À100 kJ mol À1 ,t hat is,t he formation of Zn(cys) 2 is thermodynamically favored over simple adsorption, for which, G 0 was about À25 kJ mol À1 .Last but not least, inelastic neutron scattering spectroscopy (INS) is also well suited to the study of the interaction of ametal with molecules,because the metal cages are essentially invisible to neutrons and the hydrogen rich organic molecules are strong scatters. [40,41] As shown in Figure 4F,a dsorption and entrapment are completely different:Inthe adsorbed case,the molecule spectrum is very similar to that of pure cysteinew ith only minor difference,w hile major differences are observed in the entrapment case.I ti sn oticeable that the disappearance of SÀHi n-plane bend and significant attenuation of the NH 3 rock only occurs in cys/Zn II @Ag, which points to the formation of Zn-cysteine complex.…”

Enhanced inhibition of steel corrosion by L‐cysteine under visible‐light illumination

“…In addition to physical adsorption, numerous studies revealed that the effectual inhibition on steel and copper surface is through coordinating the donor center of thiol group to the empty orbital of bare metal atoms . The resulting complex may act as either inhibitor or catalyst depending on inhibitor concentration, exposure media pH, and its chemical stability . Therefore, the inhibitor molecule must possess strong affinity toward the bare metal atoms.…”