摘要
以1,4-双(三乙氧基硅基)苯和2-(二苯基膦)乙基三乙氧基硅烷为混合硅源,在表面活性剂作用下共缩聚得到二苯基膦功能化的有序介孔有机硅材料[PPh2-PMO(Ph)],通过配位作用将Rh(Ⅰ)有机金属催化剂固载到PPh2-PMO上得到Rh(Ⅰ)-PPh2-PMO(Ph)非均相催化剂,并采用FTIR、NMR、XRD、TEM和氮气吸附等手段对催化剂进行了表征.考察了该催化剂在水介质Heck反应中的催化性能,实验结果表明,所制备的Rh(Ⅰ)-PPh2-PMO(Ph)具有与均相催化剂Rh(PPh3)3Cl相当的催化活性,这主要归因于催化剂的高比表面积、有序介孔结构有利于提高Rh(Ⅰ)活性位的分散度,减少了传质阻力;同时PMO构建形成的微环境增强了表面疏水性,有利于反应底物的吸附和扩散.此外,催化剂重复使用多次后活性仍没有明显降低.
Periodic mesoporous Rh（Ⅰ） organometallic catalyst[Rh（Ⅰ）-PPh2-PMO（Ph）] was synthesized by coordinating Rh（PPh3）3Cl complex with PPh2-ligand originally incorporated into the phenyl-bridged periodic mesoporous organosilica（PMO） via surfactant-directed co-condensation approach.The Rh（Ⅰ） he-terogeneous catalyst were characterized by FTIR,NMR,XRD,TEM and N2 sorption technologies.This catalyst can be effectively applied in water-medium Heck reaction,which results demonstrated it afforded similar catalytic performance to that of the corresponding homogeneous catalyst.It could be attributed to the large surface area and ordered mesoporous channels of the PMOs support,leading to the high dispersion of Rh（Ⅰ） active sites and the reduced diffusion limit.Meanwhile,the phenyl fragments embedded in the pore walls could enhance surface hydrophobility,which further promoted the diffusion and adsorption of organic molecules,leading to the enhanced activity.Besides,the Rh（Ⅰ）-PPh2-PMO（Ph） could be used repetitively,showing a good potential in industrial applications.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第6期1195-1199,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:50943048)资助
关键词
周期有序介孔材料
有机金属催化剂
固载化
HECK反应
水介质
Periodic mesoporous silica material
Organometallic catalyst
Immobilization
Heck reaction
Water-medium
