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Exploring vinylene-linked nanoporous covalent organic framework (COF) materials has become a valuable research focus due to their various outstanding properties. However, only a few examples have been reported to construct vinylene-linked COFs, which seriously restricted their applications. Herein, two COFs linked by olefins TC-PT and TC-PB via the Knoevenagel condensation of 1,3,5-tris-(4-cyanomethylphenyl) benzene and 2,4,6-tris (4-formylphenyl)-1,3,5-triazine or 1,3,5-tris (4-formylphenyl) benzene were designed and constructed, which possessed high crystallinity, remarkable porosity, and high structural, chemical, and thermal stability. The two nanoporous organic framework materials prepared can be used for catalytic organic reaction of phenylboric acid and its derivatives driven efficiently by visible light. It is noted that TC-PT with a donor–acceptor structure presented excellent activity, yield, and recyclability. We believed that this work would provide some precious insights for developing functional vinylene-linked COFs. [ABSTRACT FROM AUTHOR]

Currently, in situ monitoring of the adenosine triphosphate (ATP) level in lysosomes is critical to understand their involvement in various biological processes, but it remains difficult due to the interferences of limited targeting and low resolution of fluorescent probes. Herein, we report a classic Mn(II) probe ( FX2-MnCl 2 ) with near-infrared (NIR) nonlinear (NLO) properties, accompanied by three-four photon transition and fivefold fluorescence enhancement in the presence of ATP. FX2-MnCl 2 combines with ATP through dual recognition sites of diethoxy and manganese ions to reflect slightly fluorescence lifetime change. Through the synergy of multiphoton fluorescence imaging (MP-FI) and multiphoton fluorescence lifetime imaging microscopy (MP-FLIM), it is further demonstrated that FX2-MnCl 2 displays lysosome-specific targeting behavior, which can monitor lysosome-related ATP migration under NIR laser light. This work provides a novel multiphoton transformation fluorescence complex, which might be a potential candidate as a simple and straightforward biomarker of lysosome ATP in vitro for clinical diagnosis.

Mitochondrial membrane potential (MMP) and sulfur dioxide (SO 2 ) significantly affect the mitochondrial state. In this work, TC-2 and TC-8 were constructed through side-chain engineering, in which TC-2 bearing the poorer hydrophobicity could localize on mitochondria better. Interestingly, short-wave emission was captured due to the sensitive response of TC-2 to SO 2 (LOD = 13.8 nM). Meanwhile, the probe could bind with DNA, presenting enhanced long-wave emission. Encouragingly, TC-2 could migrate from mitochondria to the nucleus when MMP was decreased, accompanied by the increase of fluorescence lifetime (9-fold). Hence, TC-2 could be used for dual-channel monitoring of mitochondrial SO 2 and MMP, which showed a completely different pathway from the commercial MMP detectors JC-1/JC-10. The cellular experiments showed that MMP was gradually decreased due to reactive oxygen species-triggered oxidative stress, and the SO 2 level was up-regulated simultaneously. Overall, this work proposed a new method to investigate and diagnose the mitochondrial-related diseases.

Considering the multiple biological barriers before the entry of photosensitizers (PSs) into cytoplasm, it is of paramount importance to track PSs to elucidate their behaviors and distributions to guide the photodynamic therapy (PDT). Also, the developed PSs suffer from strong oxygen dependency. However, reports on such ideal theranostic platforms are rare. Herein, we developed a theranostic platform ( CMTP-2 ) based on the coumarin-based D-π-A system, which, for the first time, can reveal the holistic intracellular delivery pathway and near-infrared (NIR)-activated mitophagy to guide synergistic type-I PDT and photothermal therapy. The dynamic endo-lysosomal escape of CMTP-2 was monitored, as well as its changeable distributions in endosomes, lysosomes, and mitochondria, demonstrating the preferential accumulation in mitochondria at the end. Upon NIR-I irradiation, CMTP-2 generated toxic radicals and heat, triggering the execution of mitophagy and apoptosis. In vivo experiments on mice indicated that CMTP-2 under 808 nm irradiation realized complete cancer ablation, showing great potential for advancements in synergistic phototherapy.

Antibacterial agents with two-photon absorption are expected to play a significant role in biomedical science. Herein, two novel organotin complexes, HLSn1 and HLSn2, based on coumarin were designed, synthesized, and systematically investigated. It was found that these complexes possessed suitable two-photon-active cross sections in the near-infrared region. Moreover, complex HLSn1 could efficiently inhibit the growth of Gram-negative Escherichia coli and Gram-positive Bacillus subtilis, especially the latter with a minimum inhibitory concentration (MIC; 90%) of 2 ± 0.14 μg mL -1 , which is lower than that of Kanamycin (Kana, 8 ± 0.42 μg mL -1 ). Importantly, two-photon imaging and superresolution development of bacterial stain revealed that complex HLSn1 can react with bacterial membranes, producing reactive oxygen species (ROS) and leading to cell death. These outcomes provide promising applications in the superresolution bacteria imaging, diagnostics, and treatment of bacterial infectious.

A KO t Bu-promoted direct coupling reaction of phenols and [60]fullerene was disclosed. The reaction occurs exclusively at the C4-position of phenols with high regioselectivity and provides an efficient and inexpensive manner to various 4-[60]fullerephenols in good yields. The electrochemical properties of the products render the method attractive and valuable.

A two-photon fluorescent probe (J1) that selectively stains intracellular nucleolar RNA was screened from three water-soluble terpyridine derivatives (J1-J3) with quaternary ammonium groups. The photophysical properties of J1-J3 were systemically investigated both experimentally and theoretically, revealing that J1-J3 possess large Stokes shifts and the two-photon absorption action cross sections range from 38 to 97 GM in the near-infrared region. This indicates that J1 could specifically stain nucleoli by targeting the nucleolar rRNA from the recognition experiments in vitro, the two-photon imaging experiments, and the stimulated emission depletion in vivo. The mechanism of action in which J1 binds to the nucleolar rRNA was researched via both experiments and molecular modeling. The high binding selectivity of J1 to nucleolar RNA over cytosolic RNA made this probe a potential candidate to visualize rRNA probe in the living cells.

It is still a challenge that organotin(IV) carboxylate complexes with high-performance two-photon activity for cancer therapy. At present work, two novel organotin carboxylate complexes LSn1 and LSn2 , containing coumarin moiety, were rationally designed for two-photon fluorescent imaging and anticancer purpose. The complexes possessed large two-photon action cross-sections and high quantum yields. Living cells evaluation revealed that complexes LSn1 and LSn2 exhibited good biocompatibility and deep-tissue penetration over femtosecond laser with wavelength of 840 nm. Furthermore, the antitumor active and as well as possible mechanism of complexes LSn1 and LSn2 have been investigated systematically. The results indicated that complexes LSn1 and LSn2 could induce apoptotic cell death through a mitochondrial dysfunction and ROS elevation pathway. The present work provides a strategy for rationally designing organotin(IV) carboxylate complexes with two-photon activity and antitumor activity.

The KO t Bu-mediated three-component coupling reaction of indoles, [60]fullerene, and haloalkane has been developed as a practical and efficient protocol for the one-pot synthesis of various 1,4-(3-indole)(organo)[60]fullerenes. The reaction exhibits high regioselectivity at the 3-position of indoles and the 1,4-position on the [60]fullerene core. Furthermore, this methodology features excellent functional group tolerance, such as chloro, ester, cyano, and nitro on indole.

Direct coupling of indoles with C60 has been achieved for the first time. Transition-metal-free KO(t)Bu-mediated reaction of indoles to [60]fullerene has been developed as a practical and efficient method for the synthesis of various 1,2-(3-indole)(hydro)[60]fullerenes that are otherwise difficult to direct synthesize in an efficient and selective manner. This methodology tolerates sensitive functionalities such as chloro, ester, and nitro on indole and builds molecular complexity rapidly, with most reactions reaching completion in <1 h. A plausible reaction mechanism is proposed to explain the high regioselectivity at the 3-position of the indoles and the formation of 1,2-(3-indole)(hydro)[60]fullerenes.

Here we have designed and synthesized a novel analogous cis-platinum complex (TDPt) with strong two-photon absorption properties and higher stability upon laser irradiation. Interestingly, a higher cytotoxicity against three types of cancer cells compared to that of commercial cis-platinum was observed. The initial confocal micrographs showed that lysosomes may be the biological targets of such TDPt, except the conventional presumed DNA. This hypothesis was further confirmed by the two-photon microscopy and transmission electron microscopy micrograph. These results form an important basis for future "on-site observation" of the anticancer mechanism of the Pt(II) complex.

A family of air-stable (phenylbuta-1,3-diynyl)palladium(II) complexes were designed and prepared in a facile synthetic procedure. Their structures were characterized by (1)H and (13)C NMR, MS, and X-ray analysis. These Pd complexes were revealed to efficiently initiate the polymerization of phenyl isocyanides in a living/controlled chain growth manner, which led to the formation of poly(phenyl isocyanide)s with controlled molecular weights and narrow molecular weight distributions. (13)C NMR analysis indicated the isolated poly(phenyl isocyanide) was of high stereoregularity. The Pd unit at the end of the polymer chain could undergo further copolymerization with phenyl isocyanide monomers to give block copolymers. It was also found that incorporation of an electron-donating group on the phenyl group of the Pd complex could improve the catalytic activities. Furthermore, these Pd complexes were tolerant to most organic solvents and applicable to a wide range of isocyanide monomers including alkyl and phenyl isocyanides and even phenyl isocyanide with bulky substituents at the ortho position and diisocyanide monomers. Therefore, this polymerization system is versatile in the preparation of well-defined polyisocyanides with controlled sequence. Bi- and trifunctional Pd complexes with two and three Pd units incorporated onto the same phenyl ring were designed and synthesized. They were also able to initiate the living polymerization of phenyl isocyanide to afford telechelic linear and star-shaped polyisocyanides with controlled molecular weights and narrow molecular weight distributions.

Eight triphenylamine (TPA)-based Schiff bases that exhibit different aggregation-induced emission (AIE) or aggregation-caused quenching (ACQ) behavior in tetrahydrofuran (THF)/water mixtures have been synthesized and characterized. The photophysical properties in solution, aqueous suspension, film, and the crystalline state along with their relationships were comparatively investigated. The single-crystal structures of 1-8 indicate that compact π···π stacking or excimers induce fluorescence quenching of 1, 2, 5, and 7. However, the existence of J aggregates or multiple intra- and intermolecular interactions restrict the intramolecular vibration and rotation, enabling compounds 3, 4, 6, and 8 to exhibit good AIE character. The size and growth process of particles with different water fractions were studied using scanning electron microscopy, which demonstrated that smaller uniformly dispersed nanoparticles in the THF/water mixtures favor fluorescence emission. The above results suggest that the combined effects of multiple forces caused by structural variation have a great influence on their molecular packing, electronic structure, and aggregation-induced fluorescence properties. In addition, piezofluorochromic experiments verified the potential applications of 4 and 6.

A series of new isophorone derivatives (1-5), incorporating the heterocyclic ring or aza-crown-ether group, with large Stokes shifts (>140 nm), have been synthesized and characterized. 1-4 display aggregation-induced emission behaviors, while dye 5 is highly emissive in solution but quenched in the solid state. It was found that the tuning of emission color of the isophorone-based compounds in the solid state could be conveniently accomplished by changing the terminal substituent group. The photophysical properties in solution, aqueous suspension, and crystalline state, along with their relationships, are comparatively investigated. Crystallographic data of 1-4 indicate that the existence of multiple intermolecular hydrogen bonding interactions between the adjacent molecules restricts the intramolecular vibration and rotation and enables compounds 1-4 to emit intensely in the solid state. The size and growth processes of particles with different water fractions were studied using a scanning electron microscope, indicating that smaller globular nanoparticles in aqueous suspension are in favor of fluorescence emissions. The above results suggest that substituent groups have a great influence on their molecular packing, electronic structure, and aggregation-induced emission properties. In addition, fluorescence cell imaging experiment proved the potential application of 5.

Two bis-β-diketones, RCOCH(2)CO-EPTZ-COCH(2)COR (EPTZ = 10-ethylphenothiazine; R = C(6)H(5) for H(2)L(1) and CF(3) for H(2)L(2)) and their cyclic dinuclear Zn(II), Cd(II), Ni(II), Mn(II), Cu(II), Co(II) complexes have been synthesized and fully characterized. Their crystal structures were determined by single crystal X-ray diffraction analysis. Their photophysical properties have been further investigated both experimentally and theoretically. The results revealed that significant enhancement of two-photon absorption cross section values were obtained for the cyclic dinuclear Zn(II) and Cd(II) complexes compared with their free ligands. Additionally, confocal microscopy and two-photon microscopy fluorescent imaging of MCF-7 cells labeled with two ligands and Zn(II) complexes reveal their potential applications as a biological fluorescent probe.

A novel sulfur-terminal Zn(II) complex Zn(S)(2)L (L = N-hexyl-3-{2-[4-(2,2':6',2''-terpyridin-4'-yl)phenyl] ethenyl}carbazole) was obtained by a facile solvothermal process. The unique feature in this new reaction design is the use of ZnS nanocrystals as a precursor and bulky chromophoric L as an ancillary ligand. The versatility of the two terminal sulfur atoms is relevant to biological system. The resulting Zn(S)(2)L complex shows two-photon excited fluorescence (TPEF), which has been proven to be potentially useful for two-photon microscopy imaging in living cells. In addition, cytotoxicity tests showed that the low-micromolar concentrations of Zn(S)(2)L did not cause significant reduction in cell viability over a period of at least 24 h and should be safe for further biological studies.