过氧铌杂多配合物位置异构体的合成、表征及催化性能

Synthesis, Characterization and Catalysis of Heteropolytungstates Containing Peroxyniobium

合成了6种钨硅杂多配合物异构体α、βi-M3H2犤SiW11(NbO2)O39犦·H2O(M=Me4N+(TMA),Bu4N+(TBA),Et4N+(TEA);βi=β1,β2,β3)。IR光谱、UV光谱、极谱、I--S2O32-滴定证明合成的杂多配合物中有NbO2基存在,183WNMR光谱证明其阴离子具有Keggin结构,催化实验结果表明,合成的化合物对烯烃环氧化反应具有催化活性,且过氧杂多配合物的催化活性高于非过氧杂多配合物,β异构体的催化活性高于α。

The six heteropoly isomers alpha,beta(i)-M3H2[SiW11(NbO2)O-39] (.) H2O(M=TMA, TBA, TEA; beta(i)= beta(1), beta(2), beta3) were synthesized and characterized. The IR, UV spectrometry, polarography and chemical titration confirmed the existence of NbO2 groups in the complexes. All their W-183 NMR spectra have six peaks, showing the Keggin structure of anions in the compounds. Experiments on oxidation of maleic acid into tartaric acid showed that the complexes containing peroxy ions exhibited higher catalytic activity than those without peroxy ions.