Excitation wavelength-dependent lanthanide-disalicylaldehyde coordination hybrid capable of distinguishing D2O from H2O.

The increasing demands in fields of anti-counterfeiting, fluorescence analysis, clinical therapy and LED illumination are urgently eager for more excellent optically switchable luminescent materials with the stable and multimodal fluorescence in single-component matrix. Herein, the lanthanide-disalicylaldehyde coordination hybrid H2Qj4/TbxEuy is proposed as an efficient luminescent matrix to connect terbium sensibilization with ESIPT (excited-state intramolecular proton transfer) effects, and three multi-emission hybrids are finally designed and synthesized by regulating Tb3+ and Eu3+ ratios. Surprisingly, the H2Qj4/Tb0.91Eu0.09 shows the excitation wavelength-dependent luminescence in solution which originates from two energy transfer ways of terbium sensibilization effect. It exhibits green and red lights under the 369 and 394 nm UV lamp, respectively. Three hybrids are further used as lab-on-a-molecule fluorescent probes to perform multianalyte detection for various solvents by selected fluorescent sensing channels. By means of PCA (principal component analysis) and HCA (hierarchical cluster analysis), all of them can successfully detect and discriminate17 common solvents, especially the H2O and D2O. Moreover, the H2Qj4/Tb0.91Eu0.09 also shows the wide linear responses of H2O content in D2O, discrimination of two-component solvent mixtures, hygroscopicity evaluation of D2O and information encryption which will advance the progress of multimodal luminescent materials and multianalyte chemosensors.

Naphthalimide-Tagged Iron(II) Spin Crossover Complex with Synergy of Ratiometric Fluorescence for Thermosensing.

Spin crossover (SCO) materials that possess switchable and cooperative fluorescence have long focused interest in photonic sensor devices to monitor the variations in the physicochemical parameters of the external environment. However, the lack of quantified cooperativity for the SCO transition operating in isolated molecules is detrimental to short-term technological applications. In this study, a pretwisted energy D-A system combining the deep-blue naphthalimide fluorophore (donor) and the FeN6 SCO chromophore (switchable acceptor) has been developed with the formula of Fe(naph-abpt)2(NCS)2·2DMF (1), where naph-abpt is N-[3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-yl]-1,8-naphthalimide. Dual emission from the naphthalimide function based on its vibronic structure exhibits a different synergy effect with SCO, providing a new platform for ratiometric fluorescence thermosensing. Theoretical calculations and optical experimental results demonstrate an excellent correlation between luminescence intensity ratio signals and magnetic data of spin transition, promising a high sensitivity of the optical activity of the ligand to the spin state of the active iron(II) ions, with the maximum relative sensitivity as 0.7% K-1 around T1/2.

A new benzo-bodipy based fluorescent probe for the highly sensitive detection of hypochlorous acid and its application in the living cells and zebrafish imaging.

Due to the highly significant biological activity of hypochlorous acid, the monitoring of its concentration in vivo has received extensive attention. In this work, a photoinduced electron transfer (PeT) based benzo-bodipy fluorescent probe BBy-T has been developed for the rapid, sensitive, and selective detection of HClO in an aqueous solution. Based on the HClO-specific oxidation reaction, BBy-T exhibited a distinct fluorescence turn-on response to HClO with a remarkable Stokes shift (84 nm), immediate response (less than 20 s), and low detection limit (13.7 nM). In addition, the bioimaging results indicated that the probe BBy-T could be applied to real-time fluorescence imaging of living HeLa cells as well as living zebrafish.

A susceptible coordination hybrid based terbium sensibilization coupled ESIPT effects for pattern discrimination of analogues.

Multianalyte detection and analogue discrimination are extremely valuable frontier areas for their wide applications in environmental, medical, clinical and industrial analyses. Nowadays, researchers rack their brains on how to develop excellent multianalyte chemosensors that have presented huge challenges in designing high-efficient fluorescent sensing materials and constructing high-throughput detection methods. In this paper, we propose a novel strategy to utilize the dual-emission fluorescent detection platform as a lab-on-a-molecule, arising from the disalicylaldehyde-coordinated hybrid H2Qj3/Tb based terbium sensibilization coupled excited-state intramolecular proton transfer effects. Using the statistical analysis (PCA and HCA) for sensing signals of three fluorescence channels (431, 543 and 583 nm), we demonstrate this elaborate chemosensor with multianalyte detection of three species (solvents, anions and cations) and pattern discrimination of analogues. As a result, the H2Qj3/Tb shows great lab-on-a-molecule characters for each set of species, resulting in the easier identification of many critical analytes (e.g., H2O, NO2- and Fe3+) and discrimination of analogues. In addition, it is also proven to be able to provide reliable content determination for an analyte, especially the NO2- (LOD = 0.37 µM), and discrimination for mixed analogues. A combination of easy-to-implement preparation procedure and data analysis technique makes this work promising for not only designing similar lanthanide-based materials but also realizing more high-efficient multianalyte sensing systems towards various potential applications.

Dual-anions engineering of bimetallic oxides as highly active electrocatalyst for boosted overall water splitting.

Bimetallic oxides have unique advantages in driving both oxygen and hydrogen evolution reactions (OER/HER). Surface engineering of bimetallic oxides is a promising way to boost the catalytic activity by the regulation of electronic structure and surface property. Herein, a dual P, S-anions modification strategy is developed to optimize the catalytic performance of CoMoO4 nanowire arrays. The formations of CoP and Co3S4 species on the CoMoO4 surface bring heterojunction interfaces for more catalytic active sites and strong electronic interaction for faster interfacial charge transfer. Benefiting from these advantages, the P, S-CoMoO4 catalyst on nickel foam (NF) delivers excellent catalytic activity and stability. The overpotentials at 10 mA cm-2 of P, S-CoMoO4/NF for HER are just 31 mV in acid media and 58 mV in alkaline media, respectively. In addition, by assembling the P, S-CoMoO4/NF as bifunctional electrodes for overall water splitting, the electrolyzer exhibits a voltage of as low as 1.66 V at a current density of 50 mA cm-2. This work put forward a new avenue for the development of advanced bifunctional electrocatalysts for water splitting.

Auxiliary alkyl chain modulated spin crossover behaviour of [Fe(H2Bpz2)2(Cn-bipy)] complexes.

Three new alkyl chain substituted complexes [Fe(H2Bpz2)2(Cn-bipy)] (pz = pyrazolyl, Cn-bipy = bipyridine alkyl chain diester, n = 3 (3), 4 (4) and 5 (5)) show versatile spin state switching behaviour with different "tail" lengths as revealed by structural and magnetic analyses. The most striking phenomenon is observed for 5 which undergoes an abrupt spin transition accompanied by thermal hysteresis of ca. 10 K, which is attributed to crystal packing effects derived from the competition between π⋯π and C-H⋯O interactions. Interestingly, each of the complexes exhibits similar gradual and complete spin crossover in methanol solution with a transition temperature around 249 K, as deduced from temperature-dependent UV-vis spectroscopy. This highlights the differences between the solid state (ligand field; crystal packing) and solution (ligand field; solvation) effects on spin crossover. This work demonstrates that the length of the complex's alkyl chain substituents on the complex can have a large impact on the transition temperature and profile of solid state spin crossover, offering a potential path to the fabrication of soft matter spin crossover materials.

Imine bond transformation of a dynamic Sm(III) macrocycle-based chemosensor: The indirect approach for detecting cyanuric chloride.

Herein, we report our strategy to develop the efficient chemosensor and real-time monitoring technique for cyanuric chloride (TCT) detection. A luminescent macrocyclic mononuclear Sm(III) complex Sm-2k bearing with two dynamic imine bonds has been constructed via the template synthesis between dialdehyde H2Qk and matched diamine 1,2-bis(2-aminoethoxy)ethane. Sensing experiments reveal that complex Sm-2k exhibits the turn-off fluorescent and colorimetric response for TCT in CH3OH. It is especially encouraging that this optical sensing process is not only rapid within 60 s but also high-efficient in the presence of TCT analogues as well as sensitive with the low limit of detection (LOD, 1.74 µM) and wide linear sensing range. Mechanism studies demonstrate that TCT sensing is mainly based on the imine bond transformation of probe Sm-2k, which is due to the increased acidity induced by TCT. Meanwhile, a smartphone-based analytical method was developed to make complex Sm-2k accessible for the real-time TCT detection by RGB value outputs. It is believed that this work can shed some constructive lights on design of chemosensors and convenient detection technique for highly reactive analytes.

An N-linked disalicylaldehyde together with its caesium ion and dichloromethane sensing performances: 'dual key & lock' LMCT-enhanced fluorescence strategy.

The development of inexpensive, selective and rapid-response chemosensors for detecting Cs+ in waste water is highly desirable in the nuclear power industry. Here we demonstrate an efficient Cs+ optical sensor based on the N-linked disalicylaldehyde H2Qj with excited state intramolecular proton transfer (ESIPT), and it will transform into the ligand-to-metal charge transfer (LMCT) process in the presence of Cs+, resulting in dramatically enhanced fluorescence together with a distinct change of color from light-green to green-yellow. Simultaneously, it is found that CH2Cl2 can serve as the quencher of LMCT-enhanced fluorescence, thus enabling selective CH2Cl2 detection in a turn-off fluorescence approach. Further detailed studies reveal that both Cs+ and CH2Cl2 sensing processes are rapid within 60 seconds. The corresponding limit of detection (LOD) values for sensing Cs+ and CH2Cl2 are as low as 0.37 mM and 0.37%. Moreover, it was also verified that Cs+ sensing is applicable in the range of pH = 7-11 and the reversibility of sensor H2Qj can be easily achieved by modulating pH values, and H2Qj is also assessed for its Cs+ sensing performces in real water samples. This H2Qj-Cs sensing system must provide a valuable reference for further Cs+ sensors.

A Novel Thin-Film Nanocomposite Nanofiltration Membrane by Incorporating 3D Hyperbranched Polymer Functionalized 2D Graphene Oxide.

In order to develop a high-performance thin-film nanocomposite (TFN) nanofiltration (NF) membrane, the functionalized graphene-based nanomaterial (GO-HBE-COOH) was synthesized by combining two-dimensional graphene oxide (GO) with a three-dimensional hyperbranched polymer, which was used as the novel nanofiller and successfully embedded into the polypiperazine-amide (PPA) active layers on polysulfone (PSU) substrates via interfacial polymerization (IP) process. The resultant NF membranes were characterized using ATR-FTIR, SEM, and AFM, while their performance was evaluated in terms of water flux, salt rejection, antifouling ability, and chlorine resistance. The influence of GO-HBE-COOH concentration on the morphologies, properties, and performance of TFN NF membranes was investigated. With the addition of 60 ppm GO-HBE-COOH, the TFN-GHC-60 NF membrane exhibited the optimal water flux without a sacrifice of the salt rejection. It was found that the introduction of GO-HBE-COOH nanosheets favored the formation of a thinner and smoother nanocomposite active layer with an enhanced hydrophilicity and negative charge. As a result, TFN NF membranes demonstrated a superior permeaselectivity, antifouling ability, and chlorine resistance over the conventional PPA thin-film composite (TFC) membranes.

High-efficient treatment of wastewater contained the carcinogen naphthylamine by electrochemical oxidation with γ-Al2O3 supported MnO2 and Sb-doped SnO2 catalyst.

1-Naphthylamine wastewater causes severe environmental pollution because of its acute toxicity and carcinogenicity in humans, which makes it difficult to reuse by conventional technologies. In this study, we report an investigation of the electrochemical catalytic oxidation of 1-naphthylamine in synthetic wastewater in a 150 mL electrolytic batch reactor with Ti/Sb-SnO(2)/PbO(2) as anode and steel plate as cathode, where the reaction was assisted by MnO(2) and Sn(1-x)Sb(x)O(2) composite materials as the catalyst and γ-Al(2)O(3) as the carrier (MnO(2)-Sn(1-x)Sb(x)O(2)/γ-Al(2)O(3)). The catalyst was synthesized by impregnating process and was characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effects of pH and current density on the efficiency of the electrochemical degradation process were also studied. It was found that MnO(2)-Sn(1-x)Sb(x)O(2)/γ-Al(2)O(3) exhibited excellent catalytic activity in the electrochemical degradation of 1-naphthylamine wastewater. The results showed that the refractory organics in wastewater can be effectively removed by this process, and a chemical oxygen demand (COD) removal efficiency of 92.2% was obtained in 20 min at pH 7.0 and current density was equal to 50 mA cm(-2). According to the experimental results, a hypothetical mechanism of electrochemical catalytic degradation was also proposed.

A second polymorph of catena-poly[[(1,10-phenanthroline-κN,N')copper(II)]-di-µ-thio-cyanato-κN:S;κS:N].

In the title coordination polymer, [Cu(NCS)(2)(C(12)H(8)N(2))](n), the Cu(II) atom is situated on a twofold rotation axis and is coordinated by two N atoms from the bidentate 1,10-phenanthroline ligand and four thio-cyanate groups to confer a CuN(4)S(2) octa-hedral geometry and resulting in a layer structure extending parallel to (100).

Poly[[µ(2)-1,2-bis-(1H-imidazol-1-ylmeth-yl)benzene-κN:N](µ(2)-tereph-thalato-κO:O)zinc(II)].

In the title coordination polymer, [Zn(C(8)H(4)O(4))(C(14)H(14)N(4))](n), the Zn(II) atom is coordinated by two N atoms from two 1,2-bis-(imidazol-1-ylmeth-yl)benzene ligands as well as by the two O atoms from two terephthalate ligands, confering a tetra-hedral coordination geometry. The bridging ligands generate a three-dimensional structure.

Bis[µ(2)-1,2-bis-(imidazol-1-ylmeth-yl)benzene-κN:N]bis-[dichloridozinc(II)].

In the crystal structure of the centrosymmetric title compound, [Zn(2)Cl(4)(C(14)H(14)N(4))(2)], the Zn(II) atom is coordinated by two N atoms from two 1,2-bis-(imidazol-1-ylmeth-yl)benzene ligands and two Cl atoms to confer a distorted tetra-hedral geometry at the metal center.

Poly[[µ(3)-N,N'-bis-(3-pyridylmeth-yl)-thio-urea-κN:N':S]iodidocopper(I)].

In the title coordination polymer, [CuI(C(13)H(14)N(4)S)](n), the Cu(I) atom is coordinated by two N atoms from two N,N'-bis-(3-pyridylmeth-yl)thio-urea ligands, as well as by the S atom of a third ligand and an I atom to confer a distorted tetra-hedral coordination at the metal centre. The coordination bonds give rise to a layer structure parallel to (010).

A rare chiral self-catenated network formed by two cationic and one anionic frameworks.

A chiral heterometallic complex, obtained from the solvothermal reaction of [Zn(4-pytpy)2](BF4)2 [4-pytpy=4'-(4-pyridyl)-2,2':6',2''-terpyridine] and CuCN, exhibits a rare self-catenated network formed by two 3D cationic and one 3D anionic frameworks.