功能化微纳米硅胶表面亚铁配位化学及其催化降解邻苯二酚的性质(英文)

Iron(Ⅱ) on Functionalised Micro/Nano Silica Gel: Surface Coordination Chemistry and Catalytic Performance for Degradation of 1,2-Dihydroxybenzene

含吡啶硫醚有机分子功能化的微/纳米硅胶粒子利用表面有机分子分别与氯化亚铁和硫酸亚铁发生配位作用,制得两种功能化材料,即FeC@L-NSiG和FeS@L-NSiG。采用红外光谱(FTIR)、紫外可见吸收光谱(UV-Vis)、热重(TGA)和扫描电镜(SEM)对这两种材料进行了表征;同时对材料表面Fe(Ⅱ)可能的配位化学性质以及其催化双氧水氧化降解邻苯二酚的性能进行了研究。为了探究两种材料表面上亚铁中心的配位化学性质,合成了类似于功能化微/纳米硅胶表面上的有机官能团(吡啶硫醚)的含"NS"杂原子的配体L,即2-((乙基硫代)甲基)吡啶。配体L与FeCl2反应后得到配合物[Fe(L)2Cl2],通过X-射线单晶衍射方法测定了它的晶体结构,并将该配合物作为对照物进行研究。结果表明:FeS@L-NSiG表现出更高的催化效果,几乎是FeC@L-NSiG的两倍。与材料FeC@L-NSiG相比,FeS@L-NSiG的催化效率上升是由于其表面上Fe(Ⅱ)中心含有更多的易离去配体(溶剂分子或水分子),从而使底物更容易接近金属中心。

Micro/nano silica gel was functionalised with pyridinylthioether moiety. Two functionalised materials, FeC@L-NSiG and FeS@L-NSiG, were obtained by the coordination of the surface organic molecules with iron （II） using FeCI2 and FeSO4 as the precursor, respectively. Both materials were characterised using FTIR and UV-Vis spectroscopies, TGA and SEM techniques. Possible coordination chemistry of the iron （I1） on the surface functionalised materials and the catalytic performance of the title materials on the catalytic degradation of 1,2- dihydroxybenzene （catechol） by hydrogen peroxide were investigated. A ligand L, 2-（ethylthiomethyl）pyridine with ＂NS＂ donor set analogous to the organic functional group immobilised on the surface micro/nano silica gel, was synthesised for the study of the coordination chemistry around the iron （ll） centre of the two materials. The control complex, [Fe （L）2C12], used in the investigation was obtained by the reaction of the ligand L with FeC12. The structure of the complex was determined by using X-ray single crystal diffraction analysis. The results suggest that the material FeS@L-NSiG shows higher catalytic efficiency by about one-fold than that of FeC@L-NSiG. This better catalytic efficiency is because that the FeS@L-NSiG has more labile ligand （s） around the metal centre compared to its analogue （FeC@L-NSiG） and hence makes the substrate easier accessed upon binding to the metal centre. CCDC： 866526.