The absorption spectra of trans-1-(3-trans-stilbenyl)-2-pyrazinylethylene(SbPyE) shows as like summation of stilbene(St) and styrytlpyrazine(StPy) because SbPyE is cross-conjugated in the ground state, therefore, St and StPy moieties absorbe light independently. The fluorescence spectra of 1:1 mixture of St and StPy varied greatly upon changing the excitation wavelength because of molar absorption coefficient differences of St and StPy at given excitation wavelengths. But, the fluorescence spectral shape of SbPyE unchanged upon changing the excitation wavelength in ethanol and various other solvents. It is attributed to the energy transfer between the cross-conjugated bichromophore(St, StPy) in the excited states. In this case emission state has StPy moiety character. The fluorescence quantum yields of StPy increase dramatically with increasing solvent polarity. On the contrary, the fluorescence quantum yields of SbPyE increased dramatically from n-hexane to methylenechloride and then decreased with increasing solvent polarity in more polar solvents than methylenechloride. This result probably comes from conformational equilibrium change in various solvents and these conformers probably have similar fluorescence spectral shapes with different emission intensities. It was observed from n-hexane solutions on addition of increasing amounts of ethanol and from thermodynamic control in methylcyclohexane and 2-methyltetrahydrofuran with decreasing temperature. Also, supporting data were obtained from fluorescence lifetime measurements by single photon counting method.
Microviscosity around the water pool generated in Aerosol-OT/hexane/water reversed micelle solutions was studied by monitoring the depolarization of solubilized probe fluorescence. The probe, SDU, used in this study was moderately polar and was proved to be solubilized between interface and hydrocarbon phase in reversed micelle solution by fluorescence quenching study with hydrophilic and hydrophobic quenchers. The microviscosity monitored by SDU was parallel with that obtained from the fluorescence depolarization study of hydrophilic probes which was solubilized in the water pool and interface. A dramatic increase in microviscosity was observed when ω value become small.
스틸벤닐피라진닐에틸렌은 바닥상태에서 교차-컨주게이션 되어있기 때문에 스틸벤닐피라진닐에틸렌의 스틸벤과 스티릴피라진 부분들은 독립적으로 자외선을 흡수한다. 바닥상태에서 교차-컨주게이션 되어있는 두개의 발색단 (스틸벤, 스티릴피라진) 간에 에너지전달이 일어나며, 이러한 이유로 발색상태는 스티릴피라진 부분의 성격을 가지는 최저들뜬 상태이다. 스티릴피라진의 형광양자수율은 용매의 극성이 증가할수록 매우 크게 증가하는데 반하여 스틸벤닐피라진닐에틸렌의 형광양자수율은 헥산에서 메틸렌클로라이드까지 용매의 극성이 증가할수록 매우 크게 증가하다가 메틸렌클로라이드보다 용매의 극성이 더 커짐에 따라서 아주 크게 감소한다. 이러한 결과는 여러가지 용매에서 회전이상질체간의 평형상태가 변하기 때문에 얻어지는 것이며 이러한 회전이성질체들은 형광스펙트럼의 모양은 비슷한 반면에 서로 다른 형광양자수율을 가진다.