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本文合成了六种含有P—V—W和V—V—W Keggin结构的杂多阴离子,并研究了它们的(31)~P、~(51)V、~(17)O-NMR谱,对于PV_xW_(12)-xO_(40)~(x+3)-(x=1～4)阴离子,当x=1时,~(31)P和~(51)V-NMR谱只有一条线,并且此线化学位移和pH无关。当x≥2时,谱线数目随着x迅速增加,其原因是几何异构体的数目和类型迅速增加。它们的化学位移δ_p,和δ_v。依赖于溶液的酸性和x,即δ)_p,随pH值和x增加而减少,而δ_v,却随pH和x的增加而增加。最后简短讨论了桥氧上质子化的影响。
Six kinds of heteropolyanions containing P-V-W and V-V-W Keggin structures were synthesized and their (31) ~ P, ~ (51) V, ~ For x = 1 for PV_xW_ (12) -xO_ (40) ~ (x + 3) - (x = 1-4) anions have only one line of ~ (31) P and ~ And this linear chemical shift has nothing to do with pH. When x ≧ 2, the number of lines increases rapidly with x due to the rapid increase in the number and type of geometrical isomers. Their chemical shifts δ_p, and δ_v. Depending on the acidity of the solution and x, ie δ) _p, decreases with increasing pH and x, whereas δ_v increases with increasing pH and x. Finally, the effect of protonation on bridge oxygen is briefly discussed.