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Precise fabrication of organic micro/nanostructures with regular morphology has gained a considerable concern in developing high‐performance optoelectronic devices, which is still a huge challenge to realize tunable morphology without the dependence on molecule packing arrangement. Herein, a thermodynamic/kinetic controlled self‐assembly for triphenylene‐7,7,8,8‐tetracyanoquinodimethane (TP‐TCNQ) cocrystal, with well‐defined microwires and microplates based on the same crystal structure, is proposed. With the low solution concentration of C = 5 mm, the comparable growth rates along [011] driven by π–π interaction and along [100] driven by charge‐transfer (CT) interaction facilitate the formation of thermodynamically favored shape of microplates. In contrast, the prominent CT interaction along [100] leads to the construction of microwires at kinetic state under high‐concentration solution of C = 10 mm. Furthermore, the prepared TP‐TCNQ microwires and microplates demonstrate isotropic photonic transmissions with the low optical loss coefficient of 0.033 and 0.042 dB µm−1, respectively. This strategy provides a novel avenue to finely construct the organic microcrystals with desired morphology for potential optoelectronics. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) materials with an aggregation‐induced emission (AIE) mechanism have great potential for use in organic light‐emitting diodes (OLEDs). In this study, the luminescent mechanism of a novel efficient aggregation‐induced, nondoped, delayed fluorescence emitter 2‐(10H‐phenoxazin‐10‐yl)‐10‐phenyl‐10H‐phenothiazine‐5,5‐dioxide (PXZ2PTO) is theoretically studied based on first‐principles calculations. The polarizable continuum model and quantum mechanics and molecular mechanics method are used to simulate the surrounding environments for molecules in the toluene solution and the solid phase, respectively. Our results show that PXZ2PTO exhibits the superior AIE property. The nonradiative decay rate in the solid phase is two orders of magnitude lower than that in toluene, caused by the suppressed geometry changes during excitations and decay channels. Meanwhile, studies of intermolecular interactions using the dimer model indicate that PXZ2PTO possesses a special highly stereoscopic structure in the solid phase, and the electron acceptor group is almost perpendicular to the electron donor group, inducing a strong steric hindrance effect between adjacent molecules and leading to enhanced intramolecular interaction. Furthermore, the excited‐state dynamics studies show that the intersystem and reverse intersystem crossing rates of PXZ2PTO are comparable to the radiative decay rate, which indicates that PXZ2PTO is an excellent potential TADF emitter with full exciton usage. Our theoretical research gives a reasonable explanation of the experimental results and provides valuable information for designing highly efficient AIE‐TADF emitters in practical OLEDs. [ABSTRACT FROM AUTHOR]

A series of supramolecular assemblies of types [Ag8(L)4](PF6)8 and [Ag4(L)2](PF6)4, obtained from the tetraphenylethylene (TPE) bridged tetrakis(1,2,4‐triazolium) salts H4‐L(PF6)4 and AgI ions, is described. The assembly type obtained dependends on the N‐wingtip substituents of H4‐L(PF6)4. Changes in the lengths of the N4‐wingtip substituents enables controlled formation of assemblies with either [Ag4(L)2](PF6)4 or [Ag8(L)4](PF6)8 stoichiometry. The molecular structures of selected [Ag8(L)4](PF6)8 and [Ag4(L)2](PF6)4 assemblies were determined by X‐ray diffraction analyses. While H4‐L(PF6)4 does not exhibit fluorescence in solution, their tetra‐NHC (NHC=N‐heterocyclic carbene) assemblies do upon NHC–metal coordination. Upon irradiation, all assemblies undergo a light‐induced, supramolecule‐to‐supramolecule structural transformation by an oxidative photocyclization involving phenyl groups of the TPE core, resulting in a significant change of the luminescence properties. [ABSTRACT FROM AUTHOR]

Three new complexes {[Cu( L1)2(NO3)2]⋅H2O}oo ( 1), {[Cu4( L2)2(OAc)8]-CH3CH2OH}oo ( 2) and [Cd2( L3)3(NO3)4(H2O)2]oo ( 3) ( L1=4-phenyl-7-(pyridine-3-yl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole, L2=4-(pyridine-3-yl)-7-phenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole, and L3=4-(pyridine-4-yl)-7-phenyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole) have been synthesized and characterized by elemental analyses, IR spectra and single crystal X-ray diffraction. The structural analyses reveal that complex 1 is a neutral 2-D network structure with a 44 topology, 2 has a 1-D neutral coordination chain with a [Cu2(CH3COO)4] dinuclear structural unit bridged by four acetate ions, and 3 is a neutral rhombohedral grid structure. All the complexes are air stable at room temperature. Furthermore, the fluorescent properties of complex 3 and corresponding ligand L3 have been investigated and discussed. [ABSTRACT FROM AUTHOR]