Fig. 4: Photophysical properties and origins of red-to-NIR CL based on amine-ester complexes.
From: Enabling nonconjugated polyesters emit full-spectrum fluorescence from blue to near-infrared
A Normalized PL spectra of DS, DS@TEA, DS@DBU, DC, DC@TEA, DC@DBU in bulk at optimal λex = 360, 380, 440, 360, 560, and 560 nm, respectively. The molar ratios of these ester-containing structures to amines are 640:1. @ represents the mixing process. B Plots of PL intensities versus treatment time for DS@TEA, DS@DBU, DC@TEA, and DC@DBU, respectively. The molar ratios of these ester-containing structures to amines are 640:1. C Temperature-dependent PL spectra and D plots of relative PL intensities of DC@DBU versus the temperature in bulk. The molar ratio of DC to DBU is 20:1. λex = 600 nm. E Normalized PL spectra of P1, P1@TEA, P1@DBU, P2, P2@TEA, P2@DBU in solid at optimal λex = 400, 380, 400, 480, 480 and 580 nm, respectively. These mixtures were obtained by soaking polyesters in amine. F Temperature-dependent PL spectra and G Plots of PL intensities versus temperature of P2-5.0DBU in dimethyl sulfoxide solution of 10−1 M. H PL spectra of P1-5.0DBU and I PL spectra of P2-5.0DBU in solid precipitated in ethanol. Treatments 0, 1, and 2 represent once-precipitated treatment without hydrochloric acid, once- and twice-precipitated treatment under hydrochloric acid of 37 wt% (5 drops of hydrochloric acid per precipitation).
