Phosphine‐Manipulated p‐π and π‐π Synergy Enables Efficient Ultralong Organic Room‐Temperature Phosphorescence

Abstract

Organic room temperature phosphorescence (RTP) attracts extensive attentions, but still faces the challenge of achieving both high RTP efficiencies (ηRTP) and long lifetimes (τRTP), due to the intrinsic contradiction between triplet radiation and stabilization. In this work, we developed three carbazole‐triphenylphosphine hybrids named xCzTPP, in which phosphine groups provide nonbonding electrons and steric hindrance to modulate intermolecular p‐π and π‐π interactions. With the rational orientations and spatial positions of functional groups, para‐substituted pCzTPP achieves high ηRTP over 10 % and more than twofold increased τRTP (>600 ms), compared to ortho‐ and meta‐ isomers. Theoretical simulation and photophysical investigation indicate that the strongest intermolecular p‐π and π‐π electronic interplays of pCzTPP harmonize high transition probability of 3pπ state and triplet stability of 3ππ state, reflecting the p‐π and π‐π synergy in RTP process.

Achieving Colorful Ultralong Organic Room-Temperature Phosphorescence by Precise Modification of Nitrogen Atoms on Phosphorescence Units

“…Bd and BCz-1 give out (photoactivated) orange ultralong phosphorescence , in a PMMA film at room temperature; BCz, N-1 and N-2 ,, all emit (photoactivated) green ultralong phosphorescence in a PMMA film at room temperature. There is no doubt that phosphorescence color is closely related to the molecular structures of Phosphorescence Units . − However, the internal structure–function relationship between phosphorescence color and the molecular structure of the Phosphorescence Unit is still unclear and should be paid close attention to. − …”

Side group dependent room temperature crystallization-induced phosphorescence of benzil based all organic phosphors

“…3,4 However, due to the potential benets purely organic RTP systems have over metal-containing counterparts, such as cost-effectiveness, biocompatibility, low toxicity, and exibility in synthesis, continuous efforts have been put into the development of efficient all organic phosphors. 1,[5][6][7][8][9][10][11][12][13][14] To realize organic RTP, efficient intersystem crossing (ISC) is necessary and molecular motion needs to be suppressed to prevent nonradiative thermal dissipation of excited energy. To promote ISC, a common approach is incorporating spin-orbit coupling (SOC) units such as heteroatoms or halogens.…”

π–π Interaction‐Induced Organic Long‐wavelength Room‐Temperature Phosphorescence for In Vivo Atherosclerotic Plaque Imaging

“…[16] Therefore, there is an urgent need for the development of phosphorescent systems with simple molecular structures. Although a simple molecular structure usually implies a short phosphorescence wavelength, [17] intermolecular interactions can effectively reduce the excited-state energy levels, thereby causing a redshift in the emission wavelength. [18] Additionally, the development of host-guest doping strategies has greatly increased the variety of guests.…”