Conjugated Iminodibenzyl Dyes Incorporating Phenolic Hydroxyl Group and Strong Electron Donating or Accepting Groups for Facilitating ESIPT and Proton Transfer in Six- or Seven-Membered Cycles
摘要
In this study, a range of conjugated iminodibenzyl derivatives D1-D6 including phenolic group and strong electro donating/accepting groups (N,N-diethylamino/nitro groups) were prepared as the target dyes, which could process internal proton transfer in excited state via six-/seven membered ring transition state (TS). Furthermore, reference iminodibenzyl dyes D7-D12, devoid of the phenolic segment, were synthesized for comparative analysis of their absorption and emission spectral properties. The internal H-bond of the target dyes was analyzed by the 1H-NMR spectroscopy and ultraviolet/visible absorption spectroscopy. As compared with the reference dyes, the steady and transient fluorescence measurements suggest that the target dyes D1-D3