Recent advances in room temperature phosphorescence of crystalline boron containing organic compounds

Abstract

In organic compounds, room temperature phosphorescence (RTP) is a rare, yet highly desirable, property that is important for a wide variety of applications, including tissue imaging, anticounterfeiting technologies, photodynamic therapy, and organic light-emitting devices. While most organic RTP molecules rely on heavy atoms or carbonyl functional groups to accelerate singlet-to-triplet intersystem crossing, in the past few years there have been several reports of RTP induced by boroncontaining functional groups. This minireview covers the recent literature on RTP of crystalline boroorganic compounds and analyzes the connections between molecular structure, intermolecular interactions, and the resulting phosphorescence.

Recent Advances in the Luminescence of Arylboronic Acids and their Heteroatom Condensates

“…substituents around the ring, which were speculated to increase the free volume around the BAHC group in the crystalline state and promote molecular motions leading to nonradiative relaxation. Interestingly, replacing oxygen with nitrogen in 62 did not perturb the phosphorescence; nor did groups like methoxy (54,60) or cyano (55,59). Another highlight of this work was the demonstrated phosphorescence of well-known boroxine 57, hinting at the potential for developing this simple scaffold in optoelectronics.…”

“…Recently, a short review article was published on the room temperature phosphorescence of crystalline organoboron compounds [59] . The reader is directed to this review for details pertaining to the relation between the solid state characteristics and luminescence; however, a few of the key reports covering BACSs will be summarized here.…”

Halide-containing organic persistent luminescent materials for environmental sensing applications

“…Long persistent luminescence, which can be captured by the naked eyes even aer removing the excitation light source, has received considerable attention in the applications of sensing, bioimaging, light emitting devices, and data encryption. [1][2][3][4][5][6][7][8] Compared with the traditional transition metal-based or rare earth-based persistent luminescent materials, organic persistent luminescent (OPL) materials have become the research focus in recent years (Scheme 1) due to their advantages of exible molecular design, easy synthesis, and low toxicity and production cost. The OPL properties are proved to be inuenced greatly by the generation and deactivation process of the triplet excitons, including the intersystem crossing (ISC) process from singlet excited states to triplet excited states and the nonradiative decay and quenching processes.…”

Molecular Thermal Motion Modulated Room-Temperature Phosphorescence for Multilevel Encryption

“…Purely organic room-temperature phosphorescence (RTP) materials with long lifetime have been widely applied in various areas, such as organic optoelectronics, biomedicine, optical sensing, and data encryption [1,2]. Over the past decade, strategies including halogen bonding [3,4], chargetransfer mediation [5][6][7], molecular-orbital hybridization [8,9], crystal engineering [10][11][12][13][14], polymer-matrix assistance [15][16][17][18][19][20], and host-guest doping [21][22][23][24][25][26] have been utilized to boost intersystem crossing and diminish nonradiative decays to realize organic RTP. Accordingly, ultralong RTP systems with emission wavelength even at near-infrared region can be achieved [27][28][29][30][31], which is promising in background-free bioimaging.…”