先合成了八種 3一取代基一4一醯基雪梨酮，然後用滴汞電極(dropping mercury electrode)研究此類雪梨酮衍生物之還原現象。結果顯示取代基常數的準確性僅有一個限制 : 半波電位的數值僅受取代基在苯環共振及其誘導效應的影響 ; 即雪梨酮衍生物之取代基，若在苯環或雪梨酮環上而為推電子基時，取代基常數(σx)為負值。若為拉電子基時，則其取代基常數為正值。然而所得的反應常數(Pi,z)為正值，甚符合修飾過的Hammett式。雪梨酮衍生物之取代基，若不在苯環或雪梨酮上，則不能符台修飾過的Hammett式。 Eight 3-substituted-4-acylsydnones were synthesized and the polarographic reaction were investigated carefully. The substituent constant show only a limited precision: The half-wave potentials are controlled by substituent inductive and mesomeric effects transmitted through the phenyl ring and sydnone rings. If an electrondonating group substituted on phenyl or sydnone ring, the substituent constant gives negative value; Whereas an electron-withdrawiog group presents positive value. And the positive value of reaction coostant (pπ,R) fit to the Modified Hammett Equation. If the substituent group was not on the phenyl or sydoone ring, the result values have large deviation.
