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In this study, by employing mixed organic ligands through rational design and metal ions as the initial reactants, a series of novel metal-organic frameworks (AHU-TW1 to 6) were synthesized by a solvothermal method. Herein, accessible Lewis base sites originating from organic ligands within MOFs act as functional sites that can interact with the analyte possessing protons and then lead to obvious variations in the fluorescence spectra. Due to their superiority, AHU-TW1, 3, 4 and 6 are able to recognize trinitrophenol (TNP) with high sensitivity and a low detection limit.

Although studies on water-repellent properties of silicon resin (SR) on cement-based materials have received tremendous attention around the world in recent years, they mainly focus on individual properties of water-repellent concrete treated with SR such as strength and water permeability resistance. However, to date, a systematic and comprehensive investigation is missing. The current study therefore investigates the influence of SR on the durability properties of cementitious materials by adding SR emulsion into integral concrete mixture and coating concrete surface with SR. The microscopic and mechanical properties and the durability performance were tested on the integral SR water‐repellent concrete (C-ISR) and SR surface water-repellent concrete (C-SSR). The obtained results indicate that SR application has no impact on hydration reaction and corresponding composition of cement-based materials, while SR addition leads to a reduction in strength and early shrinkage of cement mortar because the added SR delays the hydration reaction. Water-repellent treatment via SR can significantly reduce the water permeability of concrete, which is more apparent for surface water-repellent treatment (SSR). Furthermore, the durability properties were investigated, and the results indicate that integral SR water-repellent treatment (ISR) possesses better properties than SSR, which suggests water-repellent treatment via surface coating as an effective means to improve concrete durability.

Cement-based materials prepared with activated water induced by a magnetic field or electric field represent a possible solution to environmental issues caused by the worldwide utilization of chemical admixtures. In this contribution, electric- and magnetic-activated water have been produced. The workability and mechanical properties of cement mortar prepared with this activated water have been investigated. The results indicate that the pH and absorbance (Abs) values of the water varied as the electric and magnetic field changed, and their values increased significantly, exhibiting improved activity compared with that of the untreated water. In addition, activated water still retains activity within 30 min of the resting time. The fluidity of the cement paste prepared with electric-activated water was significantly larger than that of the untreated paste. However, the level of improvement differed with the worst performance resulting from cement paste prepared with alternating voltage activated water. In terms of mechanical properties, both compressive strength and flexural strength obtained its maximum values at 280 mT with two processing cycles. The compressive strength increased 26% as the curing time increased from 7 days to 28 days and flexural strength increased by 31%. In addition, through the introduction of magnetic-activated water into cement mortar, the mechanical strength can be maintained without losing its workability when the amount of cement is reduced.

Methane dehydroaromatization is a potential technique in converting natural gas into value-added aromatics and clean hydrogen. However, severe coking hinders industrial application of conventionally prepared Mo/ZSM-5 catalyst for methane dehydroaromatization. Usually, Bronsted acid sites (BAS) were considered the key for coking. To gain deeper insight into the coke, here we present a simple post-impregnation of Na+ to Mo/HZSM-5 to regulate its surface acidity. Influences of BAS on catalytic performance and coking behavior were thus exclusively studied. Na+ modified catalysts exhibit lower naphthalene and higher C2 selectivity, while selectivity for benzene is not obviously changed. These results contradict conventional bi-functional pathway that methane is dehydrogenated on Mo while BAS act as the center for intermediates cyclization. Characterizations and calculations indicate restricted growth of hydrocarbon pools confined in zeolite channels of Na+ modified catalysts. Hence, it is proposed that aromatization is the intrinsic property of Mo, and the Mo-associated carbonaceous species act as precursors for both coke and aromatics production.

Lipid droplets (LDs) ultrastructure progression under proteohormone stimulation provide valuable clues for understanding conditions associated with obesity and diabetes. Current available LDs probes either alter intra-LDs environments or lack photo-resistance; thus, this research domain is poorly understood. In this work, a N-B-O type BODIPY- hexylcarbazole derivative named BoCz-Lip was rationally designed while achieving specific LDs live-cell targeting. BoCz-Lip showed minimal impact on cell viability as well as internal LDs' protein, triglyceride and cholesterol level. Along with its good photostability, it can be used to monitor LDs evolution under super-resolution nanoscopy. More importantly, we concluded how proteohormone could influence LDs ultrastructure, offering a better understanding for correlating diseases at the nanoscale.

Four novel yellow-to red-emitting fluorophores with a 1-(2-hydroxyethyl) pyridinium core and different electron-donating terminal moieties (N-methylcarbazole, N,N-dibutylbenzenamine, N-methylpyrrole, and 2-methylfuran) were designed and facilely synthesized via the one-step Knoevenagel condensation. All these compounds (HPs) were characterized by 1H NMR, 13C NMR, and HRMS. Their photophysical properties including linear absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence, were systematically investigated in various solvents. And the density functional theory calculations were conducted to analyze the electronic structures of HPs. The two-photon absorption cross-sections (δ) values of HPs measured by the Z-scan technique were determined to be as large as 1354 (1HP-CZ), 4462 (2HP-BA), 836 (3HP-PR), and 2944 GM (4HP-FU) in DMSO. The two-photon action cross-sections (Φ × δ) values of 1HP-CZ and 2HP-BA in H2O measured by the two-photon induced fluorescence method were about 50 GM. 1HP-CZ, 3HP-PR, and 4HP-FU also exhibited good water solubility. Meanwhile, it was found that 2HP-BA exhibited notable aggregation-induced emission characteristic in DMSO/H2O mixture. The aggregate particle size distribution of 2HP-BA was measured by the dynamic light scattering method, and the aggregation characteristic of 2HP-BA was observed by the transmission electron microscopy. Besides, 2HP-BA also exhibited red emission. Then, HPs with relatively low cytotoxicity were used for one- and two-photon excited fluorescence imaging in living HepG2 cells. The results indicate that HPs are potential candidates in the bioimaging field due to their photophysical properties and biocompatibility.

Subcellular organelles play critical roles in the process of apoptosis. Fluorescent probes that specifically target different organelles during cell death processes to monitor cell viability has important implications. In this work, two D(donor)-π-A(acceptor) configuration molecules (A1 and A2) with considerable two-photon absorption cross section in the near infrared region have been rational designed and synthesized. Of note, the obtained two probes could target different organelles in living and fixed cells, respectively. The reasons for different organelles targeting ability of A1 and A2 are discussed in our work. It provides a promising platform for real-time monitoring of cell mortality under subcellular level.

The rational design and fabrication of two-photon excited fluorescent probes for noninvasive bioimaging with deeper tissue penetration and higher spacial resolution is a high-priority target yet grand challenge. To this end, herein, a novel amphiphilic N∧N∧N cyclometalated Pt(II) complex (Pt–N1) was designed and synthesized. Benefiting from its flexible chains and abundant electronic structure, it displayed excellent aggregation-induced emission (AIE) behavior under physiological conditions due to its self-assembly process with the proportion of water increased. As a result, Pt–N1 exhibited considerable two-photon action cross-section in aggregation state, suggesting its potential application in bioimaging.

It is well known that the silver ions (Ag+) are important in the human body, however, novel probes were lacked with good water solubility, biocompatibility and deep penetration to detect Ag+ in the organism. In this work, we report two new three-photon absorption AIE luminogens (AIEgen), abbreviated as Tpy and Tpy-Hex, whereby Tpy-Hex could detect intracellular and environmental Ag+ quantitatively at a micromolar level. Tpy-Hex binding with Ag+ possesses enhanced three-photon absorption cross-section under1550 nm excitation (NIR II window), which is indeed beneficial for deep penetration in vitro and in vivo. The mechanism underlying the changes in three photon absorption spectra caused by bromohexyl chain substitution was further explored. The fluorescence bioimaging results reveal that the proposed probe Tpy-Hex could be ultra-sensitive for detection of Ag+ in HeLa cells and poisoned mice.

Gold nanostructures have recently received increasing interest in bioimaging application. Herein, a novel nanostructure material was designed by the terminal sulfur of the S ((E)-3-(4-([2,2′:6′,2″-terpyridin]-4′-yl)styryl)-9-hexyl-9H-carbazole Zn(SCN) 2 complex) modified with Nano gold. It could be used to target mitochondria under two-photon laser confocal microscopy, due to the energy of laser irradiation gained from the absorbed photons to be dispersed as excess heat to the neighboring particles and thus to induce their fusion, compared with free complex. Furthermore, small size Nano-Au composite was synthesized with longer lifetime, larger two photon absorption cross section (σ) and third order nonlinear optical susceptibility (χ (3) ) in the near-infrared region (NIR), due to the laser irradiation induced charge transfer from complex to the gold nanoparticles, which attracting potential applications in vitro and in vivo cellular imaging.

V–K/γ-Al 2 O 3 catalysts were prepared using an incipient impregnation method and characterized by N 2 adsorption, MAS-NMR, TPR, FT-IR, XPS and Py-FT-IR techniques. The catalytic activity of V–K/γ-Al 2 O 3 in non-oxidative dehydrogenation of isobutane was investigated in a continuous flow packed bed micro reactor. The results indicate that V–K/γ-Al 2 O 3 catalysts display a bifunctional effect. Characterization study suggests that the distribution of various VO x species were influenced by vanadium loadings to a great extent. The catalytic activity of vanadium-based catalysts was consequently promoted to different degrees by diverse VO x species and the highest dehydrogenation activity was obtained for the sample with the highest dispersion of the oligomeric VO x species. The reduced state of vanadium oxide i.e. V 3 + and V 4 + sites were proved to be the catalytic active sites for dehydrogenation reaction. Moreover, the activity and selectivity of catalysts were strongly related with the acidity of the catalysts. The ratio of Lewis acid sites to Bronsted acid sites (NLS/NBS) was negatively correlated to the isobutene selectivity. Among the tested catalysts, V–K/γ-Al 2 O 3 with an optimum vanadium loading of 10% showed the highest isobutene yield of 42.5%, with ideal stability of presenting yield up to 37.8% after 10 h continuous dehydrogenation reaction.

The development of rapid, convenient, and sensitive methods for selective detection SO2 derivatives is of considerable significance in biomedical research and has become a topical objective. Herein four probes (DS1, DS2, DB1 and DB2) based on π-conjugated indolium/benzoindolium systems were designed for detection bisulfite/sulfite. The results indicated that probes DB1 and DB2 showed rapid response, high selectivity and sensitivity for bisulfite/sulfite anions with significant ratiometric fluorescent signal changes. Moreover, DB1 and DB2 were successfully applied for bioimaging SO2 derivatives in living cells under one- and two-photon confocal laser scanning microscopy. This paradigm provided a promising methodology for the design of ratiometric and two-photon bisulfite/sulfite sensors.

Mesoporous γ-Al2O3 was synthesized via a cation–anion double hydrolysis approach (CADH). The synthesized mesoporous alumina displayed a relatively high surface area, a large pore volume and a narrow pore size distribution. By applying the mesoporous alumina as a support, supported vanadium catalysts were prepared and evaluated in the dehydrogenation of propane, exhibiting a superior catalytic performance over that supported on a commercial alumina. Materials were characterized with a variety of techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, 51V magnetic angle spinning nuclear magnetic resonance, Raman spectroscopy, Fourier transformed infrared spectroscopy of pyridine adsorption and thermogravimetric-differential thermal analysis. The correlated structure–performance relationship of catalysts reveals that a higher crystallization temperature endows mesoporous alumina materials with more surface acid sites, favoring the formation of polymerized VOX...

We strategize to utilize the precursors of (imino)coumarin fluorophores to deliver novel reactive Cu(+) probes, where tris[(2-pyridyl)-methyl] amine (TPA) works as a reactive receptor towards Cu(+). To verify this strategy, CP1, a representative probe and relevant sensing behaviors towards Cu(+) are presented here. CP1 features good solubility and fast response for monitoring labile copper in aqueous solution and live cells. The sensing mechanism of CP1 is determined by HPLC titration and mass spectrometric analysis. The probe CP1 exhibits a 60-fold fluorescence enhancement and a detection limitation of 10.8 nM upon the detection of Cu(+). CP1 is further applied for imaging labile copper in live cells. This work provides a starting point for future development of Cu(+) probes, based on in situ formation of (imino)coumarin scaffolds, as well as their further investigations of copper signaling and biological events.

Two novel ferrocene derivatives, N,N-diphenyl-4-E-((1-ferrocenyl) ethenyl) aniline (1), N,N-(4,4-diethoxyphenyl)-4-E-((1-ferrocenyl)ethenyl)aniline (2), were designed, synthesized and fully characterized by 1H NMR, 13C NMR, FT-IR and MALDI-TOF-MS spectra. Structure of (1) was confirmed by X-ray diffraction analysis. The UV–visible absorption spectra of the two compounds were investigated and verified by density functional theory (DFT) calculations. Electrochemical and third-order nonlinear optical (NLO) properties have been shown by cyclic voltammetric experiments and open/closed aperture Z-scan measurements. The results show that the two compounds both are highly π-electron delocalization system, indicating potential applications as NLO materials. It is noteworthy that (1) possesses larger two-photon absorption (2 PA) coefficient β, 2 PA cross section σ and the third-order nonlinear susceptibility (χ(3)) than (2).

Two series of Zn(II) complexes, abbreviated as [Zn2·(L1)2·Cl4] (1), [Zn2·(L1)2·Br4] (2), [Zn·(L2)·Cl2]n (3), {[Zn·(L2)·Br2]·(H2O)}n (4) and {[Zn·(L2)·I2]·(H2O)}n (5), were obtained by solvothermal method from ZnX2 (X = Cl, Br, I) and thiophene-based terpyridine ligands. Single-crystal X-ray diffraction analysis showed that complexes 1–2 belong to zero-dimensional structures while complexes 3–5 possess the structures of one-dimensional coordination polymer, and such a difference can be attributed to the different N-position in the terpyridine ligands. In addition to higher thermal stabilities than ligands (up to 400 °C), the titled Zn(II) complexes exhibited strong photoluminescent emissions and good two-photon absorption within the near-infrared range in solid state. And complexes 1–5 showed large two-photon absorption coefficients: 1.404, 1.161, 1.289, 0.965 and 0.473 cm/GW, respectively, which suggested that they have potential applications in the field of two-photon dyes.

Experimental data reveal that the incorporation of carbonyl groups into polymer matrix can significantly enhance singlet oxygen ((1) O2 ) generation and suppress production of other reactive oxygen species. Excitonic processes investigated by phosphorescence spectroscopy reveal enhanced triplet-exciton generation in the modified g-C3 N4 , which facilitate (1) O2 generation through an energy transfer process. Benefiting from this, the modified g-C3 N4 shows excellent conversion and selectivity in organic synthesis.

Novel 2-substituted-4,5-diphenyl-1H-imidazoles (M1–M4) were synthesized via a three-component, one-pot reaction under solvent-free conditions. The structures were characterized by infrared, hydrogen-1 nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, mass spectrometry and elemental analysis. Their UV-visible absorption, single-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. Pumped by femtosecond laser pulses, M1 and M4 exhibit large two-photon absorption cross-sections (585 and 1193 GM in DMF, respectively). The quantum chemical density functional theory calculations offer complementary information regarding the frontier orbitals and the molecular structures, which confirm that the degree of intramolecular charge transfer plays an important role in enhancing two-photon absorption properties.

The combination of organic conducting polymer with inorganic semiconductor is one of the most important topics in developing photoelectric materials. In this work, bouquet-like polythiophene/tellurium (PTh/Te) nanocomposite was synthesized via the redox reaction of H2TeO3 and thiophene. The formation mechanism and effect factors of PTh/Te nanocomposite were discussed. It was found that the elemental Te formed in situ promoted the polymerization of thiophene, and the remainder H2TeO3 molecules adsorbed on the PTh chains made the nanocomposite soluble. The Z-scan test results show that the PTh/Te nanocomposite has a large two-photon absorption (TPA) cross-section and nonlinear optical (NLO) absorption coefficient.

Two novel trinuclear Hg(II) complexes, namely, [Hg3Cl6(L1)2] (1) and [Hg3Cl6(L2)2] (2), (L1 = trans-4-[(p-N,N-dimethylamino)styryl]-N-acetic-acidpyridinium, L2 = trans-4-[(p-N-2-hydroxyethyl-N-methylamino)styryl]-N-acetic-acid pyridinium) have been synthesized and characterized by IR spectroscopy, elemental analysis, and X-ray single-crystal diffraction. In both 1 and 2, the tri- and tetra-coordinated Hg(II) atoms are linked by the carboxyl groups, resulting in the formation of trinuclear structures. Their linear absorption, one-photon fluorescence, two-photon fluorescence, and two-photon pumped up-conversion lasing are investigated. Upon pumped by 1064 nm laser beam, complexes 1 and 2 exhibit excellent two-photon lasing at ∼627 nm.

We present a facile hydrothermal approach to synthesize Ni 0.85 Se nanosheets, in which NiCl 2 and Na 2 SeO 3 were used as precursors. The characterization results indicate that the Ni 0.85 Se nanosheets possess hexagonal crystal structure and large specific surface area. Significantly, the Ni 0.85 Se nanosheets showed excellent adsorption to methylene blue (MB) and catalytic activity to the hydrogenation of p-nitrophenol (PNP) in presence of NaBH 4 .

The new donor-π-acceptor/acceptor-π-acceptor compounds ( FQQ , KZQ , JYQ , and LVQ ) were facilely synthesized and characterized by infrared, proton nuclear magnetic resonance, mass spectrometry, and elemental analysis. Their UV-visible absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. The experiment results indicate that all these compounds exhibit relatively strong up-converted fluorescence and obvious solvatochromic effects. KZQ shows the largest σ value of 707 GM in THF upon 830 nm excitation. Its excellent optical properties provide a promising alternative as a polarity-sensitive two-photon fluorescent probe. Aided with the quantum chemical density functional theory calculations, the relationships between the structures and the properties were studied.

Five novel 2, 2′:6′, 2″-terpyridine derivatives (L1-L5) with subtle substitute changes have been designed and synthesized. Their structures were determined by the single crystal X-ray diffraction analysis. It was observed that L1 and L2 containing an acceptor (–NO2) group exhibited three strong absorption bands, while L3, L4 and L5 containing donors (–OCH3/NH2) exhibited two absorption bands similar to that of ligand L0. Two-photon absorption cross sections were measured by two-photon excited fluorescence and open aperture Z-scan methods, respectively. Further, the two-photon absorption properties were explained by the hybrid density functional theory (DFT/B3LYP). The results indicated that L5 with amino group possessed the largest two-photon absorption cross-section values. The systematic investigations revealed that the linear/nonlinear optical properties could be tuned by subtle terminal unit changes for the Donor–Acceptor framework. Due to the existed –NH2 moiety, the subcellular acidic organelle targeting in living cells finally observed using such compounds under two-photon confocal microscopy.

Two new lanthanide(III) complexes were designed and synthesized: DAS[M(TTA)4]–, (M = Sm [1], M = Eu [2]), each of them contained one trans-4-[4′-(N, N-dimethylamino)styryl]-N-methyl pyridinium (DAS) cationic moiety, four 2-thenoyltrifluoroacetone anions (TTA-), and one cationic lanthanide(III). Herein, the structures were confirmed by single-crystal X-ray diffraction analysis. The results revealed that the central lanthanide(III) atom was fashionable eight-coordinated with square-antiprismatic coordination environment. Meanwhile, the photophysical properties of 1 and 2 were investigated by fluorescence spectra. It was proposed that there was an antenna effect and the energy transfer took place from the DAS cationic moiety to lanthanide(III) ions.

A series of novel D–π–A type two-photon absorption (2PA) imidazole-pyrimidine derivatives ( EX-1∼EX-4 ) have been synthesized and characterized, with EX-1 was crystallography confirmed. Based on systematic photophysical investigations, the structure–property relationships can be drawn as follows: (1) Both theoretical and experimental studies indicated that the different donor groups have large influences on the optical properties. (2) The 2PA cross-section values ( σ ) were obtained both by Z-Scan and two-photon excited fluorescence (2PEF) measurements. 2PA cross sections show an increasing trend with increasing electron-donating strength and the number of branches. (3) Comprehensively considered the optical performance, molecular volume, cytotoxicity and solubility, EX-1 and EX-2 were identified to be the best candidates for living cells (HepG2) imaging. Moreover, the 2PA excitable features of EX-1 and EX-2 are capable of imaging in fresh mouse's liver tissues with a depth of ca. 70 μm.

A 3-D cadmium(II) organic framework with a fourfold interpenetrated diamond topological structure, {[CdLBDC]·(H2O)2}n (1), was synthesized through zwitterionic ligand H3LBr3 (1,1′,1″-(2,4,6-trimethylbenzene-1,3,5-triyl)-tris(methylene)tris(4-carboxypyridinium)tribromide), secondary ligand H2BDC (1,4-benzenedicarboxylic acid) and Cd(NO3)2·4H2O by solvothermal method. Compound 1 was characterized by elemental analyses, FT-IR spectroscopy, powder, and single-crystal X-ray diffraction and thermogravimetric analysis. The photophysical properties of 1 were investigated by solid-state diffuse reflectance spectrum. In 1, each L is linked by two separate Cd(II)-centered distorted tetrahedra, which are also linked by two L, thereby forming a head-to-tail connected 2-D layer structure and further building the 3-D framework through BDC2−-chelating-bridging between layers.

Four novel alkynylplatinum(II) terpyridine complexes, [Pt(C CPhR)L]Cl (L = (E)-4′-(4- N, N-bis(2-(2-methoxyethoxy)ethylamino)styrylphenyl)-2,2′:6′,2″-terpyridine (O4TPY) or 4′-p-N, N-bis(2-hydroxyethyl)aminobenzyl-2,2′:6′,2″-terpyridine (TPYOH) and R = n-Bu or H), were synthesized and characterized using 1H NMR, 13C NMR, MALDI-TOF-MS and elemental analysis. All Pt(II) complexes were weakly emissive at ambient temperature in a mixed solution of acetonitrile and water, in which two alkynylplatinum(II) complexes of TPYOH showed much longer emission maximum than those of O4TPY (677 nm for [Pt(C CPh) (TPYOH)]Cl vs 581 nm for [Pt(C CPh) (O4TPY)]Cl and 689 nm for [Pt(C CPhBu) (TPYOH)]Cl vs 595 nm for [Pt(C CPhBu) (O4TPY)]Cl). UV–vis titration experiments indicated that only two alkynylplatinum(II) complexes of O4TPY can bind CT-DNA and the binding constant Kb was 1.9 × 105 for [Pt(C CPh) (O4TPY)]Cl and 1.1 × 105 for [Pt(C CPhBu) (O4TPY)]Cl, respectively. The circular dichroism results indicted that the complexes [Pt(C CPhR) (O4TPY)]Cl can change the helicity of DNA, while the complexes [Pt(C CPhR) (TPYOH)]Cl could interact with the DNA base pair. The influence of ligands in the four complexes on their emission and DNA binding properties were discussed.

A novel Schiff base ligand L and its mononuclear nickel complex Ni(L)2(SCN)2 were designed, synthesized and characterized by elemental analysis, IR spectra, MS, 1H-NMR spectroscopy, and single-crystal X-ray diffraction analysis. The crystals of L and Ni(L)2(SCN)2 belong to orthorhombic crystal system with the space group of P212121 for L and Pbcn for Ni(L)2(SCN)2, respectively. The center atom Ni(II) is coordinated with six nitrogen atoms in a distorted octahedron coordination environment. The four N atoms of them are from the two independent ligands and the other two nitrogen atoms from two SCN−. Their photophysical properties of the ligand and its Ni(II) complex were investigated and interpreted on the basis of theoretical calculations (TD-DFT).

A series of new zinc(II) complexes (Dyes 1–3) were obtained by self-assembly of the donor-bridge-donor (D–π–D) type ligand L with ZnX2 (X = Br, I, SCN). The single crystal of Dye 3 was obtained by slow evaporation of a mixture solution of methanol and dichloromethane. The molecular structure has been determined by X-ray crystallography. Hydrogen bonds (C–H⋯N, C–H⋯S) play significant roles in the final topological structures. Linear and nonlinear optical properties of the ligand and complexes were investigated in details. Experimental results revealed that effective two-photon absorption (TPA) cross sections of these complexes are larger than that of ligand L (18.7 GM) with the maximum values of 88.7 GM (Dye 1), 41.9 GM (Dye 2) and 46.5 GM (Dye 3) in DMF, respectively. The biological imaging result shows that L and Dyes 1–3 had excellent penetrability in living cells.

A convenient and rationally designed water-soluble two-photon excited fluorescence (TPEF) sensor for monitoring viscosity with specific targeting at the subcellular level remains a challenge. Herein, we reported a novel water-soluble ratiometric TPEF chemosensor EIN that is specifically responsive and singularly sensitive to mitochondria viscosity in living cells. Because its fluorescence emission bands at two different wavelengths show obvious enhancement with increased solvent viscosity, we found that the fluorescence intensity ratio (I569/I384) versus the logarithm of the viscosity (log η) enables monitoring and quantifying of abnormal changes of mitochondria viscosity. More importantly, EIN was successfully utilized to distinguish the normal and nystatin treated HepG2 cell viscosity difference of mitochondria. In a word, the merits of the NIR property, high selectivity and signal ratio provide a more convenient means for studying biological processes and mitochondria viscosity related diseases.

Imaging of RNA in living cells is a potential tool to understand intracellular RNA function. Therefore, an effective two-photon fluorescent probe with a reasonable two-photon action cross-section to label RNA is now urgently required. In this work, a series of novel two-photon absorbing terpyridine ZnX2 (X = Cl, Br, I) complexes have been designed and an effective RNA imaging probe has been obtained. The results revealed that OTP-ZnCl2 possesses large Stokes shift and two-photon action cross-section. Furthermore, live cell imaging experiments indicated that OTP-ZnCl2 could stain nucleoli in living cells by binding with nucleoli RNA. The mechanism of selective nucleoli staining of OTP-ZnCl2 was studied systematically via both experiments and molecular modeling calculations. Due to its low cytotoxicity, good membrane permeability and counterstain compatibility with the commercial fluorescent nucleic acid dye Hoechst 33342, as well as its ability to label RNA in living cells, OTP-ZnCl2 is a promising candidate for the detection of nucleic acid in living cells.

Two novel D–π–A structural thiophene-based pyridine (N^N^N or N^N^C) chromophores have been designed and synthesized. Then they were characterized by 1H NMR, 13C NMR, IR, MALDI-TOF-MS and single crystal X-ray diffraction analyses. Photophysical properties including UV-vis absorption, fluorescence, and two-photon absorption (2PA) spectra were systematically investigated using both theoretical and experimental methods. The results indicated that the thiophene-based chromophores displayed high fluorescence quantum yields and large active 2PA cross-sections in the near infrared region. Due to their excellent 2PA properties, low toxicity and low molecular weight, two-photon fluorescence microscopy (2PFM) images of HepG2 cells were captured, which suggested their potential applications in biological studies.

A novel fluorescent probe for Zn 2+ has been designed and synthesized based on a dipicolylamine group connected by a benzimidazole amide backbone. A comprehensive analysis of the recognition ability of the probe towards metal ions was conducted by ultraviolet absorption and fluorescence emission spectroscopy. Results demonstrated that the probe showed selective and sensitive fluorescence turn-on signaling behavior toward Zn 2+ in HEPES buffered (pH = 7.4) aqueous solution. The detection limit of this probe was calculated to be 5.10 × 10 −8 M for Zn 2+ . Fluorescent imaging inside HepG2 cells indicated potential application of the probe for detecting Zn 2+ ions in living cell imaging.

Three branched molecules (T1–T3) were synthesized through simple step to realize or enhance two-photon absorption (2PA) in aggregates. Spectra data show that one- and two-branched molecules (T1 and T2) possessed remarkable AIE properties, which came from the formation of J-aggregation because of their partial planarization in an aggregated state. SEM and DLS illustrate that the ordered aggregation and the small particle size had an important influence on fluorescence emission. Open aperture Z-scan experiments show that T1 and T2 possessed excellent 2PA properties in the aggregated state. The largest 2PA cross section was 8314 GM for T2 in aggregates, which was about 13-fold higher than that in pure solution. All the results demonstrate that the compounds could obtain outstanding 2PA performance by rationally adjusting their structure or changing state, which could provide a reference for preparing strong 2PA compounds.

A ‘Λ’ structural A–π–D–π–A type triphenylamine derivative (2E,2′E)-3,3′-(4,4′-(phenylazanediyl)bis(4,1-phenylene))diacrylic acid (abbreviated as L) with intramolecular charge transfer (ICT) character has been designed, synthesized and characterized. The morphology and linear optical properties of L nanostructures can be tuned by changing the solvent and/or the acidity of the solution. The possible growth mechanism is discussed through the single crystal structure and the corresponding molecular stacking style of L molecules. Further, the strong coordination effect between the carboxylic acid group of L and the metal ions is discussed, which also brings about changeable morphology, linear optical properties and enhanced nonlinear optical properties, two photon absorbance (TPA) included, which makes them suitable for applications in two-photon biological imaging, such as in HepG2 cells.

Exploring efficient semiconductors for water splitting to produce hydrogen is considered as one of the most promising approaches to solve the world energy crisis. Herein, for the first time, we highlight that metal-free siloxene nanosheets can serve as a photocatalyst for efficient water splitting without the addition of any cocatalyst or sacrificial agent.

As a semi-autonomous organelle, the eukaryotic mitochondrion possesses an individual DNA and protein synthesizing system. Therefore, the mitochondrial DNA-targeting probes are powerful tools to understand the functions in physiological processes. Herein, we report a novel Ru(ii) complex (HLRu) based on a phenanthroline derivative to target mitochondrial DNA. The nonlinear optical property study revealed a reverse nonlinear optical refraction character from self-focusing to self-defocusing response before and after complexation with Ru(ii). Furthermore, the two-photon absorption and high biocompatibility of complex HLRu highlight its potential applications in biological processes. It was found that complex HLRu specifically binds to mitochondrial DNA in living cells and enables imaging of tissues with minimal auto-fluorescence. As a result, this complex HLRu probe offers a promising platform to directly monitor mitochondrial DNA in living cells.

Novel donor–π–acceptor (D–π–A) and donor–π–acceptor–π–donor (D–π–A–π–D) type pyrimidine imidazole derivatives with flexible ether chains (L1 and L2) have been efficiently synthesized through improved Knoevenagel condensation and Ullmann reactions with high yields. Based on systematic photophysical investigations and theoretical calculations, the structure–property relationships can be described as follows: (1) the linear and nonlinear optical properties of the target chromophores change regularly with increasing the number of branches and the polarity of the solvents. (2) The single-substituted chromophore L2 exhibited a remarkable negative solvato-kinetic effect, while the double-substituted chromophore L1 showed a positive solvato-kinetic effect. Significant bathochromic shifting of the emission spectra and larger Stokes shifts were observed in polar solvents. (3) The two-photon absorption (TPA) cross-section results further demonstrated that their TPA cross section values (δ) increase notably with increasing branch number, and the presence of high π-delocalization could induce large size-scalable TPA enhancements. (4) By comprehensively considering the optical performance, cytotoxicity and solubility, L1 was identified as the better candidate for living cell (HepG2) imaging.

A novel M3L2 cage-based microporous coordination polymer assembled from the six-coordinated Cd(II) ion and a flexible tricarboxylic ligand has been designed and synthesized. The solvent-dependent luminescence properties revealed that the coordination polymer has an obvious, enhanced luminescence in the solvents CH2Cl2 and CHCl3.

An easily available triphenylamine–isophorone-based Schiff base was synthesized and its specifically triple-addressable molecular photo-switching behaviour via copper ion recognition, trans–cis isomerization and ring closure were investigated in detail. Firstly, compound Lo was able to real-time monitor Cu2+ in an acetonitrile solution via displaying the “turn-on” emission in the near infrared region with high selectivity, and sensitivity. Furthermore, two independently photochromic phenomena based on the distinct mechanisms were found surprisingly, one through the ring closure of the thiosemicarbazide moiety based on a Michael addition reaction in tetrahydrofuran solution and another through the trans–cis isomerization of aldimine (–CN–) in the solid state under the stimuli of UV/visible light. Finally, fluorescence imaging experiments in living cells demonstrated the potential practical applications in biological systems.

By combination of the AIEE-active fluorophore and coordination binding group, a new selective and sensitive probe ( 1 ) for Hg 2+ detection has been synthesized. 1 exhibits weak fluorescence in dilute solution, but exhibits dramatically enhanced emission in aggregation. In the solid state, a remarkable red-shifted emission and longer PL lifetime of 1 are present, which is caused by the formation of excimers due to the π–π stacking interactions of the coumarin groups. This AIEE effect of 1 is utilized to design probe for the detection of Hg 2+ in a luminescence “turn-on” mode. The functionalization of the AIEE-active molecule with chelating group provides the potential binding sites for Hg 2+ . The selective coordination-induced aggregation bursts the emission. 1 has been successfully applied to detect Hg 2+ in aqueous and living cells.

Five triphenylamine derivatives containing cyclohexyl have been designed and synthesized with a solvent-free green procedure. The compounds possess high quantum yields both in solution and solid state. Our investigation shows that the steric effects of the chair conformation cyclohexyl and strong intramolecular hydrogen bond play a key role for the high emission. Moreover, a conjugated triphenylamine core and strong polar groups (pyridinyl and hydroxy) and their location in the molecule formed a typical non-planar push–pull electronic structure. This special chemical structure endows the molecules with solvatochromic effect and exhibit interesting fluorescent behavior in binary solvent systems of THF-H2O due to the strong intramolecular charge transfer (ICT), which has been confirmed by DFT calculation, absorption and fluorescence spectra of the compounds in different polar solvents. In addition, their high emission characters, both in solution and solid state are utilized for picric acid (PA) detection.

Four conjugated organic triphenylamine-based mixed-valence chromophores, T1–T4, with large two-photon absorption (2PA) across sections were designed, synthesized and fully characterized by IR, MS, EI and NMR spectroscopy. Photophysical properties and mixed-valence characters of them were investigated. It was found that T4 displayed prodigious 2PA response when extending conjugation system and enriching electron density within the molecule. The enriched electron character of T4 makes it to be selectively oxidized with copper salt in solution, forming stable mixed-valence state and then used for colorimetric detection of Cu2+ ions. A simple device was fabricated using T4 for “naked eye” detection of Cu2+. The device can detect Cu2+ as low as 0.01 μM.

In fluid catalytic cracking (FCC) unit, basic nitrogen species in heavy oil result in the poison of Y zeolite acid sites and the loss of heavy oil conversion. To solve this issue, Y/ZrO2 composites are prepared by a two-stage crystallization method. The composite bears a uniform particle size and micro-mesoporous hierarchical structure. The Zr–O–Si chemical bonds are observed between Y zeolite and ZrO2 in Y/ZrO2 composites, which result from the incorporation of Zr species into the framework of Y zeolite. Compared to the mechanical mixture of Y zeolite and ZrO2, composites have abundant Lewis acid sites, which capture basic nitrogen species to protect the acid sites over Y zeolite. It endows a higher heavy oil conversion (increased by 2 wt%) to the Y/ZrO2 composites in the catalytic cracking of heavy oil with high-basic nitrogen compounds. It is worth noting that the hierarchical pore structure of Y/ZrO2 composite inhibits coke deposition. These results are important to propose a new FCC catalyst to catalytic crack heavy oil with high amount of bulky basic nitrogen compounds.

The evaporation of water from chloride-contaminated concrete during drying process causes reverse convection of chloride ions, resulting in chloride ions to accumulate on the concrete surface, thus affecting concrete durability and service life. In this contribution, the pre-dried treatment, capillary absorption test, free diffusion test, drying test were carried out to experimentally investigate the influence of diffusion and convection on chloride transport. RCM test, isothermal adsorption and desorption test and constant permeability test were used to determine the simulation parameters, thus allowing an accurate simulation of the experiment results. Chloride transport was dominated by the inward diffusion in the free diffusion test, whereas chloride migration in the drying test was affected by the coupling effect of inward diffusion and outward convection. The shorter test days led to a more prominent effect of the reverse convection. The chloride diffusion coefficients varied with the pre-dried days, water-to-cement-ratio and diffusion test type with the best chloride resistance coming from specimens with lower water-to-cement-ratio and shorter pre-dried days. The numerical results agreed fairly well with experimental results obtained from the capillary absorption test, diffusion test and drying test.

Targeting mitochondria and dynamically tracking mitophagy are profoundly important in the field of photodynamic therapy (PDT) which relies on the photosensitizers (PSs) under light irradiation. While simultaneously realizing the effective reactive oxygen species (ROS) generation, accurately mitochondrial targeting, and dynamic tracking in a single PS still is a challenging issue. In this context, a series of pyridinium-based cationic fluorogens with aggregation induced emission (AIE) has been developed for this issue. The hydrophobicity of these fluorogens can be finely tuned by modulating the length of the alkyl chains on pyridinium unit. The well-tuned hydrophobicity of TL8C with C8-alkyl chain gives rise to the specifically mitochondrial targeting capability of TL8C based on the appropriate synergistic effect of hydrophobic and electrostatic interaction. Meanwhile, TL8C can produce ROS in high efficiency. The excellent mitochondrial targeting and the effective ROS generation allow TL8C for the specifically mitochondria-targeted PDT as well as the real time monitoring of mitophagy.