Mercaptopropyl groups

The l3C CP MAS spectra of the sample-A show the presence of the most prominent peak at 27.2 ppm for Ci carbon atom adjacent to the SH group and C2 carbon atom of the 3-mercaptopropyl group. There was another minor intensity broad peak at around 22.3 ppm which is assigned to C and C2 carbon atoms of the dipropyl disulfide. The presence of dipropyl disulfide in the sample A may be due to oxidative dehydrogenation of two adjacent thiol groups leading to the formation of disulfide (S-S) group. An unresolved shoulder down field to the C3 carbon of the thiol was observed for the C3 carbon of the dipropyl disulfide. Similar results were obtained by Lim et al. [6],... 

The Tf results obtained on the polysiloxane-immobilized thiol and chloro-propyl systems (Table 25.4) show that the C-detected T values obtained for the CH2 peak of the ethoxy group at 60.8 ppm, the CH3 peak of the methoxy group at 51.9 ppm, the C(2), C(3) peak of the 3-mercaptopropyl group at 28.7 ppm and the C(l) peak of the 3-mercaptopropyl group at... 

Figure 2. Grafting and coating of a mesoporous ordered Si02 with mercaptopropyl groups (R = Me, Et).

Materials with immobilised mercaptopropyl groups were oxidised with H2O2 in a methanol-water mixture. Typically 2.04 g of aqueous 35% H2O2 dissolved in three parts of methanol was used per gram of material. After 24 hours the mixture was filtered and washed with water and ethanol. The wet material was then re-suspended in 0.1 M H2SO4 solution for another 4 hours. Finally, the material was rinsed with water and dried at 60 C under vacuum. ... 

The textural properties govern the diffusion process so that a well-defined structure may facilitate diffusion-controlled reactions. For example, the adsorption of heavy-metal ions (Hg + and Cu ) reveals a dramatic discrepancy between ordered and disordered mesoporous silica grafted with the aminopropyl or mercaptopropyl group [55]. The ordered mesostructure with a mean pore size of 6.5 nm brings about complete accessibOity of the functional groups. While... 

Wu, H.Y., Chen, C.-T., Hung, I.-M., Liao, C.-H., Vetrivel, V., and Kao, H.-M. (2010) Direct synthesis of cubic benzene-bridged mesoporous organosilica functionalized with mercaptopropyl groups as an effective adsorbent for mercury and silver ions. /. Phys. Chem. C, 114, 7021-7029. 

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