Two Calix[3]Phenothiazine‐Based Amorphous Pure Organic Room‐Temperature Phosphorescent Supramolecules Mediated by Guest

Abstract

ditions need to be met, one is to improve the inter-system crossing efficiency, and the other is to suppress the non-radiative relaxation process. [10][11][12][13][14] Based on this, many interesting RTP systems have been developed through rational design in the past few years. [15][16][17][18] For example, the introduction of heavy atoms or carbonyl and groups containing other heteroatoms with abundant lone-pair electrons into organic molecules can effectively increase the SOC constant, thereby achieving efficient intersystem crossing (ISC). [19][20][21][22][23] In addition, by introducing intermolecular charge-transfer states in single-component crystals and multi-component doping systems, the singlet-triplet energy gap can be minimized to accelerate the ISC rate to achieve phosphorescence emission. [24][25][26][27] At the same time, many brilliant strategies such as molecular aggregation (including H-aggregation, π-π stacking, and n-π stacking), [28][29][30][31] crystallization, [32][33][34][35] polymerization, [36][37][38][39] host-guest complexation, [40,41] carbon dots and clusterizationtriggered emission have also been used to construct RTP systems. [42,43] Despite the exciting development of RTP, so far, most RTP systems for pure organic compounds have been realized in the crystal state, and the demanding growth condition and uncontrollable growth process required for crystal cultivation have hindered their practical application to a certain extent. Therefore, it is imperative to design and develop a facile and general strategy to obtain amorphous pure organic compounds with efficient RTP emission.In supramolecular chemistry, the assembly strategy of hostguest complexation has excellent advantages in the fabricating of tunable and smart organic luminescent materials in aqueous media and the solid state. [44][45][46][47] In recent years, there have been more and more studies using the cavity confinement effect of the macrocycle (especially for cyclodextrin and cucurbituril) to induce organic single-molecule phosphorescence emission. [48][49][50] For example, our group reports an unprecedented enhancement of the phosphorescence quantum yield of bromophenyl-methyl-pyridinium chloride from 2.6% to 81.2% by complexing with cucurbit[6]uril. [51] However, there are few reports showing that organic single molecules induce phosphorescence of macrocycles in host-guest complexes because the charge Herein, two kinds of amorphous solid-state supramolecular systems with purely organic room temperature phosphorescence (RTP) from calix[3] phenothiazine (C[3]Pz) activated by 1,2-/1,3-dicyanobenzene (1,2-/1,3-DCB) are reported. Different from macrocycle-confined guest phosphorescence emission, RTP of these two amorphous solid-state supramolecular systems is entirely from the 1,2-/1,3-DCB rivets C[3]Pz cavity to form dense supramolecular complex through CH … π interactions, leading to two different phosphorescence emissions at 566/524 nm under 430 nm excitation, respectively. Although C[3]Pz shows a regular arrangement in ...

Odd–Even Effect in Charge Transfer Complexes through the Regulation of the Alkyl Chain

“…Inspired by these cases, we developed a new CT complex system and investigated the effect of packing on intermolecular CT by modifying the alkyl chains. Triazatruxene (TAT) and its derivatives TAT-nC (n = 1–6) (Figure ) are planar extended π-conjugated structures with C 3 symmetry, which can be considered as electron-donating units, − and cyano-substituted benzenes are commonly used acceptor molecules. , We selected them as the donors and acceptors, respectively. When the donor of TAT-nC was mixed with the 1,3,5-benzenetricarbonitrile (TCNPh) acceptor at a 1:1 molar ratio, it exhibited typical intermolecular charge-transfer properties with red-shifted absorption and TADF emission.…”

Structurally Diversified Calix[3]phenoxazines: Synthesis, Solid-State Conformational Investigation, and Host–Guest Chemistry

“…Calix­[ n ]­thiophene and calix­[ n ]­furan are some of the early examples of heteroatom-containing macrocyclic arenes. Calix­[ n ]­pyrrole, diphenylamine­[ n ]­arene, calix­[ n ]­carbazole, calix­[ n ]­phenothiazine, calix­[ n ]­acridan, and acridane­[ n ]­arene are macrocyclic arenes based on nitrogen-containing building blocks (Figure b). These nitrogen-containing macrocyclic arenes can be obtained via a one-step condensation reaction.…”