Fig. 3. Mechanism of color-tunable UOP in multicomponent copolymer at room temperature.
a Phosphorescence excitation spectra in polymer PDNA at 445 and 517 nm. b Normalized phosphorescence spectra of monomer MDP and MND in 2-methyltetrahydrofuran (1 × 10−5 M) at 77 K (top), as well as polymer PDA and PNA at room temperature (RT) (bottom) excited at 280 and 360 nm. c Polymer film excitation–phosphorescence mapping of PDA (top) and PNA (bottom) at room temperature. d WAXS pattern of polymer film PDNA. e Natural transition orbitals for the lowest triplet transitions of MDP and MND in gaseous state. f Proposed mechanism of the color-tunable UOP in multicomponent copolymer. Fluo. fluorescence, Phos. molecular phosphorescence, Exc. excitation.