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Developing luminescent radicals with tunable emission is a challenging task due to the limitation of alternative skeletons. Herein, a series of carbene‐triphenylamine hybrids were prepared by the direct C2‐arylation of N‐heterocyclic carbenes with 4‐bromo‐N,N‐bis(4‐methoxyphenyl)aniline. These hybrids showed multiple redox‐active properties and could be converted to carbon‐centered luminescent radicals with blue‐to‐cyan emissions (λmax: 436–486 nm) or nitrogen‐centered luminescent radicals with orange emissions (λmax: 590–623 nm) through chemical reduction or oxidation, respectively. The radical species were characterized by electron paramagnetic resonance spectroscopy, ultraviolet‐visible spectroscopy, and single‐crystal X‐ray diffractometry analysis. Notably, the corresponding nitrogen‐centered radicals exhibited good stability in atmospheric air, and their thermal decomposition temperatures were determined to be above 200 °C. In addition, spectral and theoretical calculations indicate that all radicals exhibit anti‐Kasha emissions. [ABSTRACT FROM AUTHOR]

Thanks to the potential of aggregation‐induced emission (AIE) phenomena, improved stabilities, and the good selectivity and sensitivity of the chemical responses exhibited by the products, coordination‐driven self‐assembly with tetraphenylethylene (TPE) units has recently received much attention and has been widely investigated for application in chemical sensors, cell imaging agents, light‐harvesting systems, and others. Several reviews have emerged on the topics of AIE chemistry and aggregation‐induced emission luminogen (AIEgen)‐based supramolecular assembles, however, there is still a distinct lack of full overviews of emission enhancement from the viewpoint of metal‐coordination effects. Thus, this minireview offers recent advances that have been made in the design and application of TPE‐based metallacycles, metallacages, metal‐organic frameworks (MOFs) and coordination polymers (CPs). [ABSTRACT FROM AUTHOR]

The metal‐controlled self‐assembly of organometallic molecular cylinders from a series of imidazo[1,5‐a]pyridine‐based tris‐NHC ligands is described in this report. The imidazo[1,5‐a]pyridinium salts H3‐L(PF6)3 (L=4 a–4 c) were treated with 1.5 equivalents of Ag2O to yield the trinuclear AgI hexacarbene cages [Ag3(L)2](PF6)3 (L=4 a–4 c), in which three AgI are sandwiched between the two tricarbene ligands. The silver(I) complexes [Ag3(L)2](PF6)3 underwent a facile transmetalation reaction in the presence of 3 equivalents of [AuCl(tht)] (tht=tetrahydrothiophene) to furnish the trinuclear AuI cylinder‐like cages [Au3(L)2](PF6)3 (L=4 a–4 c) without destruction of the metallosupramolecular structure. The new hexacarbene assemblies feature a large cavity that can easily accommodate a molecule of dimethyl sulfoxide as molecular guest. This is the first study of a unique "host–guest" system containing an organometallic cylinder‐like cage derived exclusively from poly‐NHC ligands. Well done imidazopyridine! A set of novel organometallic molecular cylinders comprising imidazo[1,5‐a]pyridine‐based tris‐NHC ligands is described. The incorporation of imidazo[1,5‐a]pyridine scaffolds into the poly‐NHC ligands enhances the cavity size of the new trinuclear metallacages prepared by a silver‐ and gold‐mediated self‐assembly strategy. The metallacages have potential in molecular recognition (see figure). [ABSTRACT FROM AUTHOR]

The internal cavity size of a metallosupramolecular assembly can be tuned by thoughtful design of the ligand. This work reports the introduction of imidazo[1,5‐a]pyridine scaffolds in place of the conventional imidazol‐2‐ylidene moieties, which resulted in new molecular containers bearing significantly enlarged cavities. The new hexacarbene metal assemblies can easily accommodate a dimethylsulfoxide molecule as a molecular guest. This is the first study of a unique "host–guest" system featuring an organometallic cylinder‐like cage exclusively derived from poly‐NHC ligands. More information can be found in the Full Paper by Y.‐F. Han et al. on page 5472. [ABSTRACT FROM AUTHOR]