A systematic spectral analysis was presented for bishemicyanine dyes(Hsd and D2)and monohemicyanine dyes(Hs and DSMI).The bishemicyanine dyes displayed long emission wavelengths,large Stokes shifts,low background quan...A systematic spectral analysis was presented for bishemicyanine dyes(Hsd and D2)and monohemicyanine dyes(Hs and DSMI).The bishemicyanine dyes displayed long emission wavelengths,large Stokes shifts,low background quantum yields in aqueous solutions and high sensitivity in viscous environments.Better understanding of the structure-property relationships could benefit the design of improved dyes.Computational studies on these dyes revealed the three conjugated forms of bishemicyanines are in equilibrium due to two positive charges and a branched bulk substituent.Bishemicyanines possessed obviously lower rotating energy barrier of C-C bond rotation compared to the monohemicyanine dyes.Moreover,the synergetic effects of the rotation about theφ4 bond,φ5 bond andφ7 bond of the bishemicyanines(Hsd and D2)lead to lower fluorescence quantum yields in a free state and larger fluorescence quantum yield enhancements in viscous environment compared to that of monohemicyanine dyes(Hs and DSMI).The results demonstrate a foundation for interpretation of the behavior of the dyes,thus providing guidelines for future of new bishemicyanine fluorophores with specific applications.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21606118)the State Key Laboratory of Fine Chemicals(No.KF1614)。
文摘A systematic spectral analysis was presented for bishemicyanine dyes(Hsd and D2)and monohemicyanine dyes(Hs and DSMI).The bishemicyanine dyes displayed long emission wavelengths,large Stokes shifts,low background quantum yields in aqueous solutions and high sensitivity in viscous environments.Better understanding of the structure-property relationships could benefit the design of improved dyes.Computational studies on these dyes revealed the three conjugated forms of bishemicyanines are in equilibrium due to two positive charges and a branched bulk substituent.Bishemicyanines possessed obviously lower rotating energy barrier of C-C bond rotation compared to the monohemicyanine dyes.Moreover,the synergetic effects of the rotation about theφ4 bond,φ5 bond andφ7 bond of the bishemicyanines(Hsd and D2)lead to lower fluorescence quantum yields in a free state and larger fluorescence quantum yield enhancements in viscous environment compared to that of monohemicyanine dyes(Hs and DSMI).The results demonstrate a foundation for interpretation of the behavior of the dyes,thus providing guidelines for future of new bishemicyanine fluorophores with specific applications.
