Excitation-Dependent Triplet–Singlet Intensity from Organic Host–Guest Materials: Tunable Color, White-Light Emission, and Room-Temperature Phosphorescence

Abstract

A series of organic host–guest materials with multifunctional luminescence were constructed. Four isoquinoline derivatives were used as the guests, and benzophenone was used as the host. The doped system exhibited excellent dual emission with cyan fluorescence and orange-yellow room-temperature phosphorescence, and the dual emission could be combined into almost pure white-light emission. Importantly, the relative intensity of the fluorescence–phosphorescence could be adjusted by changing the excitation wavelength, with the phosphorescence intensity being significantly higher than the fluorescence intensity under shorter excitation wavelengths and vice versa under longer excitation wavelengths. Therefore, three-color emission switching among cyan, white, and orange could be achieved by simply adjusting the excitation wavelength. The results of experimental and theoretical calculations indicated that the excitation-dependent emission colors were caused by different transfer paths for excitons under different excitation wavelengths. These materials with multifunctional luminescence could be used as writable inks for advanced anticounterfeiting.

Constructing Ultralong Near-infrared Organic Phosphorescence Materials with 732 nm through One-axis Two-wing Guest-Host Strategy for Bioimaging

“…S4), which is in line with our previous works. [40][41][42][43] Four other guest-host materials (MOPy/BPO, MAPy/BPO, DMOPy /BPO, and DMAPy/BPO, Fig. 1a) with the guest-host molar ratio of 1:1000 were further prepared, and the luminescence characteristics of the host-guest systems were systematically investigated.…”

“…In our previous works, we found that the host could assist the excitons of the guests in energy transfer. [41][42][43] So in this work, we first tested the excitation spectra (fluorescence emission/420 nm) of guest MAPy in common solvents (toluene, THF, and N,N-dimethylformamide/DMF) and host BPO (molten state and crystal state). As show in Fig.…”

“…Recently, guest-host materials have gradually attracted more attention, [34][35][36][37][38][39][40][41][42][43][44][45][46][47] because the host matrix can inhibit the non-radiative transition of the guest excitons in the guest-host system. [42][43][44][45][46][47] Additionally, some research results have shown that there is energy synergy between the host and guest molecules, which can effectively assist the guest molecules to transfer the excited state energy. [39][40][41][42][43] Therefore, the guest-host system provides a new strategy for the construction of organic RTP materials with long wavelength and long lifetime.…”

“…[42][43][44][45][46][47] Additionally, some research results have shown that there is energy synergy between the host and guest molecules, which can effectively assist the guest molecules to transfer the excited state energy. [39][40][41][42][43] Therefore, the guest-host system provides a new strategy for the construction of organic RTP materials with long wavelength and long lifetime.…”

One-axis Two-wing Guest-Host Strategy for Constructing Ultralong-lifetime Near-infrared Organic Phosphorescence Materials for Bioimaging

“…Recently, guest-host materials have gradually attracted more attention, [34][35][36][37][38][39][40][41] because the host molecules can inhibit the non-radiative transition of the guest energy in the guest-host system. [42][43][44][45][46][47] Additionally, several research results have shown that there is a synergy of energy between host and guest molecules, which can assist the guest molecules to transfer the excited state energy effectively. [39][40][41][42][43] Therefore, the guest-host system provides a new strategy for the construction of organic RTP materials with long-wavelength emissions and long lifetimes.…”