Substituent Effects On The Reduction Potential, Fluorescence And Infrared Properties Of 4,4’-disubstituted N-benzylidenebenzenamines

A series of 4,4’-disubstituted N-benzylidenebenzenamine derivatives p-XPhCH=NPhY-p(abbreviated XBAY) are synthesized, their molecular structure are determined by Nuclear magnetic resonance spectroscopy (NMR), the oxidation-reduction potential and the fluorescence spectrum as well as IR spectrum of these compounds are measured respectively.Using XBAY as target compounds, the rules are investigated between the substituent effect and reduction potential (E(Red)). The result shows that there is no linear relation between their E(Red) and the δc(C=N) of the 13C NMR of C=N bridge bond in the molecules. The factors affecting E1(Red) are obvious different from that affecting on δc(C=N), and the change regularity of.E(Red) can not be expressed well by only employing Hammett substituent constant, and the excited-state substituent constant of substituent X plays an important role of influence on E(Red).The rule has been studied about the substituent effect and Fluorescence emission wave (vem) of XBAY. It is found that the vem of these compounds has a good correlation with the polar substituent constant, the excited-state substituent constant and the interaction effects of groups; by comparing the correlation equations about the Fluorescence emission spectra and the substituent parameters of two similar structurally conjugated systems which are 4,4-disubstituted stilbene derivatives p-XPhCH=CHPhY-p(abbreviated KSBY) and XBAY, the parameters of their equations used are different. The reasons are that the C=C double bond of XSBY is non-polar bond, the vem has a good correlation with the excited-state substituent constant; while the C=N double bond of XBAY is polar bond, the vem requires the polar substituent constant, the excited-state substituent constant and the interaction effects of groups to get a good correlation.Besides, we have studied the substituent effect on C=N double bond stretching vibration frequency (v(C=N)) of XBAY. The results show that the polar substituent constant and the excited-state constant have influence on v(C=N) of these compounds, and the interaction effect of substituents (△σtp2) plays an important role of influencing on V(C=N), and couldn’t be ignored.