Yellow and Orange–Red Room‐Temperature Phosphorescence from Amorphous Nonaromatic Polymers

Abstract

Many nontraditional luminogens (NTLs) without any large π‐conjugated structures are reported to exhibit room‐temperature phosphorescence (RTP). Unfortunately, the reported NTLs mostly emit blue or green RTP. Achieving more redshifted RTP from NTLs remains a great challenge. Herein, a series of nonaromatic polymers exhibiting yellow and orange–red RTP are reported. Poly(itaconic anhydride) (PITA) does not exhibit RTP, its hydrolyzed product poly(itaconic acid) (PITAc) exhibits weak yellow RTP, but the ionized product poly(sodium itaconate) (PITANa) can emit stronger and redshifted RTP. Moreover, the ionized copolymers poly(vinyl pyrrolidone‐co‐sodium itaconate) (PIVPNa) and poly(vinyl pyrrolidone‐co‐sodium maleate) (PMVPNa), the mixture of PITANa/poly(vinyl pyrrolidone) (PVP), and the full hydrolyzed product of poly(vinyl caprolactam‐co‐sodium itaconate) (PIVCNa) all exhibit strong orange–red RTP emissions at ≈600 nm. Structural characterizations and theoretical calculations prove that hydrogen bonding and ionic bonds lead to the rigidification of polymer chain conformations, and more importantly, both intra‐ and interchain nonaromatic electron donor–acceptor (nDA) structures and hence through‐space charge transfer are formed between carboxylate and lactam groups in proper conformations, which facilitates the occurrence and redshift of RTP in NTLs. This work provides a novel strategy to design NTLs with redshifted RTP and improves the understanding of the photoluminescence mechanism of NTLs.

Cluster-induced aggregation in polyurethane derivatives with multicolour emission and ultra-long organic room temperature phosphorescence

“…The data show that through-space conjugation exists in the PUs. 56 Fig. S14 (ESI†) shows that there are a large number of hydrogen bonding interactions (such as C–H⋯OC, C–H⋯N and N–H⋯N), through-space dative bonds (carbonyl oxygen/ether oxygen to B atoms) and short contacts.…”

Recent Progress in Nonconventional Luminescent Macromolecules and their Applications

“…87 Wang et al reported a series of nonaromatic amorphous polymers with yellow-orange-red RTP. Multiple nonaromatic donor−acceptor (nD-A) structures with carboxylate and lactam groups of different electron donor/ acceptor capabilities, combined with short contacts, aggregation, and efficient TSCT, collectively suppressed nonradiative decay, resulting in a reduction in the energy gap and an increase in the probability of intersystem crossing (ISC), and ultimately strong, orange-red RTP at ≈600 nm, with τ ph 41 ms. 88 Luminous hydrogels/organogels based on NCLMs are still rare and their mechanical properties are largely unexplored although they offer great potential for the development and applications of soft materials. Wang et al prepared high-strength hydrogels with RTP emission based on nonaromatic polymers.…”

Hydrogen-Bonding-Driven Nontraditional Photoluminescence of a β-Enamino Ester

“…The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/molecules28165950/s1. Figure S1: 1 H NMR and 13 C NMR spectra of MAC. Figure S2: 1 H NMR and 13 C NMR spectra of MPB.…”

“…Figure S1: 1 H NMR and 13 C NMR spectra of MAC. Figure S2: 1 H NMR and 13 C NMR spectra of MPB. Figure S3: lifetime of MAC crystal under the excitation wavelength of 371.8 nm.…”

“…The overlapped π orbitals and extended delocalization of electrons lead to a reduction in the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap. Recently, however, more and more nontraditional luminogens (NTLs) (also called clusteroluminogens) without large π-conjugated structures have been reported [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. These NTLs contain electron-rich atoms such as N, O, S, and P, and/or unsaturated bonds such as C=O, C=C, C=N, and C≡N as nonconventional chromophores (NCCs).…”