一种新型镍取代Dawson型锌钨酸配合物的合成及对苯乙烯氧化制苯甲醛的催化性能研究

A novel Dawson-based coordination polymer for selective oxidation of styrene to benzaldehyde

报道了一种新型配合物的合成方法,在80℃条件下将Ni(NO3)2·6H2O与阴离子主体[Na12(H2O)38][WZn{Mn(H2O)}2(ZnW9O34)2]·3H2O在水溶液中反应得到了黄绿色的晶体,经TGA、IR、元素分析和X-射线单晶衍射表征证实为镍取代Dawson型锌钨酸配合物,其化学式为[Ni(H2O)6]2{[Ni(H2O)4]2[Ni(H2O)5]2WZn[Ni(H2O)]2(ZnW9O34)2}·10H2O.实验结果表明当催化剂的负载量为2%,苯乙烯与过氧化氢物质的量比为1:4,反应温度50℃,反应时间10h时,苯乙烯氧化反应的转化率达到90%,苯甲醛的选择性达95%,催化剂经处理后可重复使用.该配合物对氧化苯乙烯制苯甲醛具有优良的催化活性和高的选择性。

The reaction of [Na12（H2O）38]·3H2O and Ni（NO3）2·6H2O in water at 80 ℃ afforded Kelly crystals of a novel polymer,which has been characterized by TGA,IR,element analysis and single crystal X-ray diffraction.The novel Dawson-based coordination polymer [Ni（H2O）6]2{[Ni（H2O）4]2[Ni（H2O）5]2WZn[Ni（H2O）]2（ZnW9O34）2}·10H2O was an excellent catalyst for the oxidation of styrene with high styrene conversion（up to 90%） and high benzaldehyde selectivity（up to 95%）.The results showed that the suitable reaction conditions for this reaction were the amount of catalyst was 2%,the molar ratio of hydrogen peroxide and substrate was 1∶4,at 50 ℃ for 10 h.