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Organic molecules and polymers have recently been intensively explored for afterglow materials owing to their low cost and flexible design. However, they normally fail to generate long-persistent luminescence at elevated temperatures, mostly due to the fast deactivation of triplet excited states. Here, we report that polycyclic aromatic compounds (PACs) individually confined in a B2O3crystalloid emit long-persistent luminescence at high temperatures up to 400 °C. This is facilely accomplished by dispersing a series of aromatic derivatives in an aqueous solution of boric acid, followed by drying, melting, and dehydrating. The resulting highly rigid and thermostable B2O3crystalloid network provides a matched ultrastrong confinement effect and completely restricts the vibration and rotation of the molecularly distributed PACs even at ultrahigh temperatures and thereby prevents the nonradiative dissipation of triplet excitons and promotes the generation of ultrahigh-temperature long-persistent luminescence. The afterglow colors are responsive to both temperature and time, spanning from ultraviolet to near-infrared regions over a wide temperature range, which is substantially modulated by the subtle balance of phosphorescence and thermally activated delayed fluorescence. These features favor the creation of advanced afterglow materials for visual 3D temperature probing, anticounterfeiting, and data encryption in extreme environments.

Copper-powder-catalyzed syn-selective chlorosulfonylation of readily available alkynes by an atom transfer radical addition (ATAR) process has been developed, providing straightforward access to a broad range of (Z)-β-chlorovinylsulfones in good yields under mild conditions. In addition, this method is ligand-free and features excellent stereoselectivity and high atom economy. Moreover, the product was obtained without an apparent loss of yield when the reaction was performed on the gram scale at a low catalyst loading. In this reaction, the copper powder not only acts as a sulfone radical initiator but also produces the catalytically active CuCl species. Mechanistic investigations and DFT calculation studies revealed that the stereoselectivity is controlled by the thermodynamic stabilities of the in situ-generated cyclic alkenyl CuIIcomplex intermediate, which can serve as a chlorine atom transfer agent.

Specific cancer diagnosis at an early stage plays a significant role in preventing cancer metastasis and reducing cancer mortality. Thus, exploring specific and sensitive fluorescent probes to realize early cancer diagnosis is an urgent need in clinic. Aminopeptidase N (APN/CD13), overexpressed in numerous malignant tumors, is an important tumor biomarker associated with cancer progression, invasion, and metastasis. In this study, a novel fluorescent molecule APN–SUB, capable of monitoring APN in real time, is encapsulated in a pH-responsive block copolymer (termed APN–SUB nanoprobe) for cancer diagnosis. APN–SUB contains a fluorophore center and a trigger moiety (leucine group), which is covalently conjugated on the fluorophore with an amide bond. The hydrolysis of the amide bond in APN–SUB activated by APN leads to a red shift of maximum fluorescence emission wavelength from 495 nm to 600 nm, realizing dual-color transformation from green to red. Moreover, the APN–SUB nanoprobe with pH-responsiveness is prepared to improve the accumulation and the release rate in the tumor region. It is worth noting that the APN–SUB nanoprobe exhibits good performance for APN imaging, namely, superior limit of detection (0.14 nU mL−1), excellent selectivity and strong photostability. More importantly, the APN–SUB nanoprobe can be successfully employed as a color-convertible fluorescent probe for cancer diagnosis by tracking the activity of APN with high specificity and sensitivity in vivo, demonstrating its potential value for cancer diagnosis.

We report a facile and tailored method to prepare globally twisted chiral molecular cages through tunable coordination of bis-bipyridine-terminated helicene ligands to a series of transition metals including Fe(II), Co(II), Ni(II) and Zn(II). This system shows an efficient remote transfer of stereogenecity from the helicene core to the bipyridine-metal coordination sites and subsequently the entire cages. While the Fe(II), Co(II) and Ni(II)-derived M2L3(M for metal and L for ligand) cages exhibit quasi-reversible redox features, the Zn(II) analogues reveal prominent yellow circularly polarized luminescence. Interestingly, with the addition of Na2SO4, the Zn2L3cages reassemble into sextuple-stranded Zn6L6(SO4)4cages in which three Zn2L2units are bound together by four sulfates and further coalesced by offset inter-ligand π-πinteractions.

Symmetry breaking in the self-assembly of achiral constituents is of vital importance for the origin of molecular homochirality and developing advanced chiral materials. Here, we report a unique mode of spontaneous symmetry breaking in the aggregates of aza[4]helicenes with an achiral vibrating helical conjugated structure. The achiral molecules initially form clustered aggregates with a slight chiral bias of the Pand Misomers, and subsequently the chiral imbalance is amplified by the conversion of the Pand Mconformations to favor a more thermodynamic stable π–π stacking (from PMto PPor MMstacking). The dynamical P/Mtransformation not only promotes the evolution of optical activity following the initial spontaneous symmetry breaking but also favors the healing of chirality after the majority is eliminated by heating. Notably, the aggregates reveal prominent circularly polarized luminescence with the absolute dissymmetry factor approaching 0.01. This work provides additional insights into the pathway of chiral symmetry breaking and illustrates a unique route to develop optically active materials from achiral helical molecules.

Bottom-up synthesis of carbon nanomaterials embedded with periodic arrays of nanoporous structures is of great interest for potential applications in nanotechnology. In limited examples, lateral fusion of polymer chains or armchair/chevron graphene nanoribbons with phenyl functional groups upon dehydrogenative coupling has been observed for the generation of porous nanoribbons or nanoporous graphene. Here we report a stepwise on-surface synthesis of porous carbon nanoribbons upon hierarchical Ullmann coupling for promoting highly selective inter-ribbon connections, which results in porous carbon nanoribbon structures with a notched zigzag edge and variable widths. By combining scanning tunneling microscopy and atomic force microscopy, the nanoporous structure and the corresponding electronic structures are fully characterized, which shows that localized electronic states are generated at pore–ribbon interfaces and ribbon zigzag edges. Further first principle calculations unveil the observed electronic states near the Fermi level originating from the two flat bands upon nanoporous structure imprinting. Our results provide a promising strategy for the atomically precise synthesis of porous carbon nanoribbons with engineered electronic structures, which can potentially enrich the synthetic routes to porous nanostructures and also expand the variety of carbon nanomaterials with characteristic electronic properties.

Here, we describe a novel strategy for chemoselective synthesis of α-halo-α,α-difluoromethyl ketones (−COCF3and −COClCF2motifs) from trimethyl(phenylethynyl)silane under catalyst-free and mild conditions. Commercially available Selectfluor or additional NaCl as halogen reagent was employed to complete this transformation, thereby demonstrating the potential synthetic value of this new reaction in organic synthesis.

Nanographenes (NGs) with twisted backbones are emerging as new candidates for chiroptical materials. In this work, we describe a new strategy for synthesizing a [10]twistacene-embedded NG which exhibits a rare flag-hinge-like geometry. By neatly creating steric crowding on the [6]helicene breaches of the NG skeleton, the synthesis only provided homochiral isomers without generating the “meso-” isomer. The formed NGs showed high luminescence with quantum yield up to 52%, and promising circularly polarized luminescence (CPL) performance with |glum| up to 5.0 × 10−3. Besides, these NGs also showed outstanding CPL brightness (BCPL) up to 305 L·mol−1·cm−1among chiral NGs.

Curved nanographenes (NGs) are emerging as promising candidates for organic optoelectronics, supramolecular materials, and biological applications. Here we report a distinctive type of curved NGs bearing a [1,4]diazocine core that is fused with four pentagonal rings. This is formed by Scholl-type cyclization of two adjacent carbazole moieties through an unusual diradical cation mechanism followed by C–H arylation. Owing to the strain in the unique 5–5–8–5–5-membered ring skeleton, the resulting NG adopts an interesting concave–convex cooperatively dynamic structure. By peripheral π-extension, a helicene moiety with fixed helical chirality can be further mounted to modulate the vibration of the concave–convex structure, through which the distant bay region of the curved NG inherits the chirality of the helicene moiety in a reversed fashion. The [1,4]diazocine-embedded NGs show typical electron-rich characteristics and form charge transfer complexes with tunable emissions with a series of electron acceptors. The relatively protruding armchair edge also allows the fusion of three NGs into a C2symmetric triple diaza[7]helicene which reveals a subtle balance of fixed and dynamic chirality.

Acetylacetonato‐platina[6]‐ and ‐platina[7]helicenes have been prepared from 2‐pyridyl‐substituted benzophenanthrene ligands by following a two‐step cycloplatination reaction. The photophysical properties (UV‐visible absorption and emission behavior) and chiroptical properties (circular dichroism and molar rotation) of the resolved enantiomers have been measured. These metallahelicenes constitute a novel family of easily accessible helicene derivatives that exhibit large and tuneable chiroptical properties that can be rationalized theoretically and compared to the parent [6]‐ and [7]carbohelicenes. Furthermore, they are red phosphors at room temperature and their large chiroptical properties can be modulated by oxidation of the metal center to PtIV. Hetero‐ and homochiral diastereomeric bis(metallahelicene)s that possess a rare PtIIIPtIIIscaffold bridged by benzoato ligands have also been prepared. It is shown that the heterochiral (P,M)‐bis(PtIII–[6]helicene) 9 a1can isomerize into the homochiral (P,P)‐ and (M,M)‐bis(PtIII–[6]helicene) 9 a2. Spectral assignments and an analysis of the optical rotation of these systems were made with the help of time‐dependent density functional theory. The calculations highlight the contributions of the metal centers to the chiroptical properties. For 9 a1and 9 a2, σ–π conjugation between the helicenes and the PtPt moiety may contribute strongly to the optical rotation and electronic circular dichroism.