Chiral Mn(Ⅲ) salen complex immobilized on imidazole-modified mesoporous material via co-condensation method as an effective catalyst for olefin epoxidation

An imidazole modified mesoporous material has been prepared through a co-condensation procedure and adopted to covalently anchor chiral Mn(Ⅲ) salen complex. The active centers in the as-synthesized catalyst were presented in the form of ionic species. The results of XRD, FTIR, DRUV-Vis, and N2 sorp-tion confirmed the successful immobilization of chiral Mn(Ⅲ) salen complex inside the channels of the modified support and the maintenance of the mesoporous structure of parent support in the immobi-lized catalyst. This heterogeneous catalyst exhibited comparable catalytic activity and enantioselectiv-ity to those of the homogeneous counterpart in the asymmetric epoxidation of unfunctionalized olefins. Furthermore, notably high turnover frequencies have been obtained over this heterogeneous catalyst for the relatively short reaction time and low catalyst amount, due in part to the ionic property as well as the uniform distribution of the active centers.

co-Condensation Synthesis of Salicylaldimine Calcium Complex Containing Mesoporous Silica Nanoparticles as Carriers for Drug Release

A series of functional mesoporous silica nanoparticles（MSNs） was synthesized by a one-step simple synthesis approach involving co-condensation of tetraethoxysilane（TEOS） and salicylaldimine ligand（Sal-Si） in the presence of cetyltrimethylammonium chloride（CTAC） under basic conditions.The target MSNs with different sizes （50,100 and 200 nm,respectively） were obtained.Furthermore,the Ca^2＋ cations were also introduced into MSNs.The prepared nanoparticles were characterized by means of infrared（IR） spectra,thermogravimetric analysis（TGA）,inductively coupled plasma（ICP）,CHN elemental analysis,nitrogen adsorption-desorption,scanning electron microscope（SEM） and transmission electron microscope（TEM）.Ibuprofen（IBU） which contains carboxyl groups was selected as a model drug.The results of drug loading and release reveal that the loading capacities and release behaviors of the model drug are highly dependent on the Ca^2＋ cations in MSNs.The release of IBU from the MSNs functionalized by Ca^2＋ cations is found to be effectively controlled when compared to the release from the MSNs without the functionalization of Ca^2＋ cations,which is due to the ionic interaction between carboxyl groups in IBU and Ca^2＋ cations in MSNs.

Synthesis and Characterization of Soluble and Meltable Poly(aminopropyl/phenylsilsesquioxane)

The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane （PTES） and hydrophilic γ-aminopropyltriethoxysilane （APS） was investigated in toluene and water by using hydrochloric acid （HCl） catalyst. A soluble and meltable poly（aminopropyl/phenylsilsesquioxane） （PAPSQ） was formed by controlling HCl amounts, APS/PTES molar ratios, water/silane molar ratios （Rw/si）, organic co-solvents and re-equilibration steps as well. The compositions of PAPSQ bearing aminopropyl and phenyl groups with the capping of trimethylsilyl group were confirmed by element analysis, fourier-transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （NMR） and thermogravimetric analysis （TGA）. Differential scanning calorimetry （DSC） was employed to characterize the melting behavior of the product. PAPSQ can be easily employed as functional molecular building blocks for the synthesis of diverse and novel inorganic-organic materials.

Synthesis of Amino-Functionalized Hexagonal Mesoporous Silica for Adsorption of Pb2＋

Highly ordered amino-functionalized hexagonal mesoporous silica （HMS-NH2） had been synthesized successfully by co-condensation. The resultant materials were characterized by means of XRD, TEM, FT-IR, N2 ad-desorption and 29Si NMR to confirm the ordered mesoporous structure and the functionalization of the amino groups. The sample was employed as a Pb2＋ adsorbent in aqueous solutions at room temperature. Both Lagergren＇s first order kinetic model and Lagergren＇s second order kinetic model were used to describe the adsorption data. It was found that the pseudo second order model fitted the sorption kinetic data better than the pseudo first order model. According to the information analyzed from AAS, HMS-NH2 had a Pb2＋ adsorption amount of over 90.7 mg·g-1 , showing a promising application for the treatment of wastewater containing Pb2＋ ions.