Amorphous Ionic Polymers with Color‐Tunable Ultralong Organic Phosphorescence

Abstract

Amorphous purely organic phosphorescence materials with long‐lived and color‐tunable emission are rare. Herein, we report a concise chemical ionization strategy to endow conventional poly(4‐vinylpyridine) (PVP) derivatives with ultralong organic phosphorescence (UOP) under ambient conditions. After the ionization of 1,4‐butanesultone, the resulting PVP‐S phosphor showed a UOP lifetime of 578.36 ms, which is 525 times longer than that of PVP polymer itself. Remarkably, multicolor UOP emission ranging from blue to red was observed with variation of the excitation wavelength, which has rarely been reported for organic luminescent materials. This finding not only provides a guideline for developing amorphous polymers with UOP properties, but also extends the scope of room‐temperature phosphorescence (RTP) materials for practical applications in photoelectric fields.

A clustering-triggered emission strategy for tunable multicolor persistent phosphorescence

“…Currently, the development of smart luminescent materials with tunable multicolor emission upon external stimuli, such as temperature, light, electric/magnetic eld, excitation intensity and pressure, is receiving increasing attention because of their unique photophysical properties and potential applications in information encryption, visual detection of UV lights, anticounterfeiting, sensing and bioassays. [1][2][3][4][5][6][7][8] Thus far, despite the fact that multicolor luminescence has been successfully achieved through the modulation of crystallinity, molecular conformation/packing and composition of the compounds, or the combination of different emitters, [5][6][7][8][9][10][11][12][13] it remains challenging to realize the tunability of persistent phosphorescence in pure organic single-component systems, [14][15][16][17][18][19][20] particularly in single crystals. 14 While there is growing interest in the achievement of pure organic persistent room temperature phosphorescence (p-RTP), [21][22][23][24][25][26][27] little attention has been given to its tunability, [14][15][16][17][18][19][20] presumably because of the high susceptibility of triplets 28-38 and the difficulty in the construction of diverse triplet emissive populations.…”

“…Very recently, tunable multicolor persistent phosphorescence from pure organics has been observed in certain nonaromatic luminophores, [18][19][20] aromatic crystals 14 and ionized or doped polymers, [15][16][17] at cryogenic temperatures (i.e., 77 K) and/or even under ambient conditions. For example, Huang and co-workers demonstrated tunable p-RTP in 2,4,6-trimethoxy-1,3,5-triazine (TMOT) crystals, 14 and Zhao et al reported a tunable aerglow from blue to red by tuning the aggregation state of pyrene derivatives in poly(vinyl alcohol) (PVA) lms.…”

“…[18][19][20]39 Taking together all the preceding reports, it is clear that the presence of multiple emissive centers alongside rigid conformations are necessary for tunable multicolor phosphorescence. [14][15][16][17][18][19][20] These features, fortunately, are exactly the two key points required for achieving unusual luminescence from nonconventional luminogens devoid of classic conjugates. [39][40][41][42][43] On account of the less effective delocalization of the subunits, individual non-conventional luminophores are virtually nonemissive.…”

Crosslink‐Enhanced Emission Effect on Luminescence in Polymers: Advances and Perspectives

“…This effectively stabilized the triplet excitons for ultralong RTP through the suppression of nonradiative transitions. Recently, these researchers adopted a similar ionization strategy to achieve color‐tunable RTP in poly(4‐vinylpyridine) derivatives …”

A Synergistic Enhancement Strategy for Realizing Ultralong and Efficient Room‐Temperature Phosphorescence

“…[13] Moreover,b rilliant work of enhancing RTPb yp olymers also have been reported, such as doping into polymer [14] and copolymerization. [15] But the lifetimes were mostly in the range of milliseconds.H erein, we devise as ynergistic enhancement strategy for realizing lifetime up to 2.81 seconds and phosphorescent efficiency more than 76 %( Scheme 1). This strategy consists of two interrelated parts:p olymerization enhancement and complexation enhancement.…”