Fig. 1: Design Scheme and Spectroscopic properties of VIPIs.

AThe design strategy and structures of VIPIs as well as the control cyanine dyes (HHCy1 and HHCy2). B Normalized absorption (solid) and fluorescence (dotted) spectra of the fluorophores in chloroform. C Summarized absorption (λabs) and fluorescence (λem) wavelengths of the fluorophores in panel (B). The dashed line indicates zero Stokes shift. The vertical droplines illustrate the scales of Stokes shift. The detailed spectra of VIPIs in different solvents are shown in Fig. S1.