Electrons Transfer Between Mercaptoacetic Acid and ZnO Nanocrystal Thin Film

ZnO nanoorystals thin film were prepared by means of the self-assembly mothed. The complex films of mercaptoacetic acid(MPA) and ZnO nanocrystals(ZNCs) were prepared by means of the self-assembly technique. The interaction between the MPA and ZnO within the MPA and ZnO nanocrystal thin film decreases the photoluminescence intensity of the ZnO. The interaction was manifested by the X-ray photoelectron spectra. The intensity change of the photoluminescence of the ZnO is discussed on the basis of taking into account the process of electron transfer on the interface between the ZnO and MPA. The electron transfer of ZnO depends on the distance between the ZnO and MPA.

Determination of Surface pKa of Pure Mercaptoacetic Acid and 2-Mercaptobenzothiazole Mixed Monolayers by Impedance Titration

Interfacial proton transfer reactions of pure mercaptoacetic acid (MA) and 2-mercaptobenzothiazole (Mbz) mixed self-assembled monolayers (SAMs) have been studied using a.c. impedance titration method. The charge-transfer resistance (Rct,) is measured with the monolayer composition and the ionic strength of pH solution. The surface pKa can be obtained by the plots of Rct and pH, the reasons of shifts of surface pKa are also explained.

A catalysis study of mesoporous MCM-41 supported Schiff base and CuSO_4·5H_2O in a highly regioselective synthesis of 4-thiazolidinone derivatives from cyclocondensation of mercaptoacetic acid

Mesoporous MCM-41 supported Schiff base and Cu SO4· 5H2 O shows high catalytic activity in the cyclocondensation of mercaptoacetic acid with imines（or aldehydes and amines） to afford pharmaceutically important thiazolidinone derivatives. The catalytic reactions involving twocomponents or three-components afforded the desired product in high yields（up to 98% and 99%）.Moreover, the catalyst works well with respect to recyclability, giving the product in 85% and 83% yields after recycling six times.

Surface Dissociation Properties of Short Chain Carboxyl Mercaptan Self-Assembled Monolayers by Impedance Titration

Impedance titration was used to determine the surface dissociation characteristics of short-chain carboxyl mercaptan self-assembled monolayers （SAMs）. Based on the change of the cyclic voltammetric peak current and the charge-transfer resistance, which was related to pH value of the solution, the surface pKa of mercaptoacetic acid（MA）, 3-mercaptopropionic acid（MPA） and ω-mercaptohexanic acid（MHA） self-assembled membranes, with ionic strength being 0.1 mol/L, were determined to be 5.20, 4.80, 7.40, respectively. In addition, factors such as time needed for assembling, structure of monolayers and ionic strength, which effected the surface pKa, were studied as well. Such surface pKa shifts were sufficiently explained by interactions between interfacial molecules and hydrophobicity.

Synthesis, Characteristic and Antimicrobial Activity of Some New Spiro[indol-thiazolidon-2,4-diones] and Bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) Probes

In a search for new antimicrobial agents, some new spiro[indol-thiazolidon- 2,4-diones] (6a-c) were synthesized by condensation of 5-substituted isatins 1 with sulfanilamide in MeOH, followed by aroylation with p-nitrobenzoyl chloride in DMF to get compounds 4a-c. Cycloaddition of 4a-c with thioglycolic acid in a dry non-polar solvent (dioxane) gave the targets 6a-c. Also, bis(5-fluorospiro[indoline-3,2’-thiazolidine]-2,4’-dione) (9) was synthesized by condensation of 5-fluoroindoline-2,3-dione with benzene-1,4-diamine (2:1 by mol) in MeOH, which followed by cycloaddition with thioglycolic acid in dioxane gave compound 8. Acylation of the later with 2,2,2-trifluoroacetic anhydride in THF has yielded the target 9. Structures of the products have been deduced from their elemental analysis and spectral data. The in vitro antimicrobial activity of the new systems 6a-c, and 9 was tested.