Fig. 4: Multi-color emissive properties of the host–guest systems.

a The calculated HOMO and LUMO energy levels of compound 1. b Changes in the fluorescence spectra upon the addition of γ-CD (compound 1: 5 μM, γ-CD: 0–10 eq). c Changes in the 1931 CIE chromaticity coordinate with the addition 0–10 eq of the γ-CD host to an aqueous solution of compound 1 (5 μM). d Fluorescence images of a solution of compound 1 (5 μM) upon addition of increasing concentrations of γ-CD aqueous solution (0−10 eq). e Fluorescence gel immersed in γ-CD aqueous solution (0.1 M) for 8, 20, 50, and 100 min. f Absolute fluorescence quantum yield of compound 1 at different concentrations upon the addition of γ-CD. g Fluorescent photographs printed by inkjet using a black cartridge that was loaded with the complex solution under natural light and UV.