Triphenylamine-Modified Cinnamaldehyde Derivate as a Molecular Sensor for Viscosity Detection in Liquids.

Liquid safety is considered a serious public health problem; a convenient and effective viscosity determination method has been regarded as one of the powerful means to detect liquid safety. Herein, one kind of triphenylamine-modified cinnamaldehyde-based fluorescent sensor (3-(4'-(diphenylamino)-[1,1'-biphenyl]-4-yl)acrylaldehyde (DPABA)) has been developed for sensing viscosity fluctuations in a liquid system, where a cinnamaldehyde derivative was extracted from one kind of natural plant cinnamon and acted as an acceptor, which has been combined with a triphenylamine derivate via the Suzuki coupling reaction within one facile step. Twisted intramolecular charge transfer (TICT) was observed, and the rotation could be restricted in the high-viscosity microenvironment; thus, the fluorescent signal was released at 548 nm. Featured with a larger Stokes shift (223.8 nm in water, 145.0 nm in glycerol), high adaptability, sensitivity, selectivity, and good photostability, the capability of high signal-to-noise ratio sensing was achieved. Importantly, this sensor DPABA has achieved noninvasively identifying thickening efficiency investigation, and viscosity fluctuations during the liquid deterioration program have been screened as well. We believed that this unique strategy can accelerate intelligent molecular platforms toward liquid quality and safety inspection.

Highly Stable Europium(III) Tetrahedral (Eu4L4)(phen)4 Cage: Structure, Luminescence Properties, and Cellular Imaging.

Luminescent lanthanide cages have many potential applications in guest recognition, sensing, magnetic resonance imaging (MRI), and bioimaging. However, these polynuclear lanthanide assemblies' poor stability, dispersity, and luminescence properties have significantly constrained their practical applications. Furthermore, it is still a huge challenge to simultaneously synthesize and design lanthanide organic polyhedra with high stability and quantum yield. Herein, we demonstrate a simple and robust strategy to improve the rigidity, chemical stability, and luminescence of an Eu(III) tetrahedral cage by introducing the conjugated planar auxiliary phen ligand. The self-assembled tetrahedral cage, (Eu4L4)(phen)4 [L = (4,4',4″-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine), phen = 1,10-phenanthroline], exhibited characteristic luminescence of Eu3+ ions with high quantum yield (41%) and long lifetime (131 µs) in toluene (1.0 × 10-6 M). Moreover, the Eu(III) cage was stable in water and even in an aqueous solution with a pH range of 1-14. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cellular imaging revealed that the Pluronic F127-coated hybrid material, (Eu4L4)(phen)4@F127, exhibited low cytotoxicity, good biocompatibility, and cellular imaging ability, which may inspire more insights into the development of lanthanide organic polyhedra (LOPs) for potential biomedical applications.

Can a molecular switch exist in both superalkali electride and superalkalide forms?

To combine both electride and alkalide characteristics in one molecular switch, it is shown herein that the phenalenyl radical and the M3 ring (M3-PHY, M = Li, Na, and K) stacked with parallel and vertical geometries are good candidates. The former geometry is the superalkali electride e-⋯M3+-PHY while the latter geometry is the superalkalide Mδ--M2(1-δ)+-PHY-. The superalkalide Mδ--M2(1-δ)+-PHY- may isomerize to the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K) using suitable long-wavelength irradiation, while the latter may isomerize to the former with suitable short-wavelength irradiation. Also, applying suitable oriented external electric fields can drive the superalkalide Mδ-M2(1-δ)+-PHY- to change into the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K). The differences in the static and dynamic first hyperpolarizability (ß0) values between them were also studied.

A Co-delivery System Based on a Dimeric Prodrug and Star-Shaped Polymeric Prodrug Micelles for Drug Delivery.

Chemotherapy is one of the commonly used therapies for the treatment of malignant tumors. Insufficient drug-loading capacity is the major challenge for polymeric micelle-based drug delivery systems of chemotherapy. Here, the redox-responsive star-shaped polymeric prodrug (PSSP) and the dimeric prodrug of paclitaxel (PTX) were prepared. Then the dimeric prodrug of PTX (diPTX, diP) was loaded into the core of the star-shaped polymeric prodrug micelles of PSSP by hydrophobic interaction forming the redox-responsive prodrug micelles of diPTX@PSSP for intracellular drug release in tumor cells. The hydrodynamic diameter of diPTX@PSSP nanoparticles was 114.3 nm ± 2.1 (PDI = 0.219 ± 0.016), and the micelles had long-term colloidal stability and the drug-loading content (DLC) of diPTX and PTX is 16.7 and 46.9%, respectively. The prepared micelles could broke under the reductive microenvironment within tumor cells, as a result, the dimeric prodrug of diP and polymeric prodrug micelles of PSSP were rapidly disassembled, leading to the rapid release of intracellular drugs. In vitro release studies showed that under the condition of reduced glutathione (GSH) (10 mM), the release of PTX was significantly accelerated with approximately 86.6% released within 21 h, and the released PTX in cytoplasm could promote the disintegration of microtubules and induce cell apoptosis. These results indicated that the new type of this reduction-sensitive nanodrug delivery system based on dimeric prodrug@polymeric prodrug micelles would be a promising technology in chemotherapy.

Regioselective Radical Reaction of Monometallofullerene Y@C2v(9)-C82 With N-arylbenzamidine Mediated by Silver Carbonate.

A novel radical reaction of monometallofullerene Y@C2v(9)-C82 with N-arylbezamidine (1) is successfully conducted through catalysis with silver carbonate. The high-performance liquid chromatographic and mass spectrum results demonstrate that the reaction is highly regioselective to afford only one monoadduct (2) with an imidazoline group added on C82 cage, and computations through density functional theory reveal the addition group is attached to a specific [5, 6]-bond (C20-C76) near the Y atom. Furthermore, the analysis of prymidalization angle of the carbon atoms demonstrates the geometry of carbon cage is in favor of the regioselective formation of isomer (20, 76).

Electric field induced intra-molecular self-redox: superalkali Li3N3Mg as a candidate for NLO molecular switches.

A novel intra-molecular self-redox switch, Li3N3Mg, is constructed theoretically. Our investigation showed that a suitably oriented external electric field (OEEF) can drive a long-range excess electron transfer from Mg atoms to Li3 rings. And subsequently, an interesting intra-molecular self-redox from Li32+N33-Mg+ to Li3+N33-Mg2+ accompanying the large different electronic static first hyperpolarizability (ß) is exhibited. The increase of the ß value constitutes an order of magnitude improvement from Li32+N33-Mg+ (34 986 a.u.) to Li3+N33-Mg2+ (101 225 a.u.), which indicates that Li3N3Mg is a good candidate for a self-redox NLO molecular switch.

Hydrothermal Preparation, Crystal Structure, Photoluminescence and UV-Visible Diffuse Reflectance Spectroscopic Properties of a Novel Mononuclear Zinc Complex.

A novel mononuclear zinc complex [ZnL(Phen)(H2O)]·H2O containing the mixed ligands of Phen (Phen = 1,10-phenanthroline) and 3-hydroxy-2-methylquinoline-4-carboxylic acid (HL) was prepared by hydrothermal synthesis and its crystal structure was characterized by X-ray single-crystal diffraction method. The title complex crystallizes in the orthorhombic systems and forms monomeric units. The molecules in the title complex are connected through the interactions of hydrogen-bonding and ????? interactions to give a three-dimensional (3D) supramolecular structure. The fluorescence result discovers a wide emission band in the violet blue region. Time-dependent density functional theory (TDDFT) calculations reveal that this emission can be attributed to ligand-to-ligand charge transfer (LLCT). Solid-state diffuse reflectance shows there is a wide optical band gap.

Preparation, Structure, Photoluminescent and Semiconductive Properties, and Theoretical Calculation of a Mononuclear Nickel Complex with 3-Hydroxy-2- Methylquinoline-4-Carboxylato Ligand.

A novel nickel complex with mixed ligands [Ni(L)2(EtOH)2(MeOH)2] (HL = 3-hydroxy-2-methylquinoline-4-carboxylic acid) has been synthesized through solvothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique. Single-crystal X-ray diffraction analyses reveals that the title compound crystallizes in the triclinic system of the P-1 space group, and exists as isolated mononuclear complex. The intermolecular hydrogen bonds lead to the formation of chains, and the layered supramolecular structure is formed by the strong ααααα stacking interactions. Solid-state photoluminescent characterization reveals that the title compound has an emission in the green region. Time-dependent density functional theory (TDDFT) calculation shows that the nature of the photoluminescence of the title compound originates from the ligand-to-ligand charge transfer (LLCT; from the HOMO of the p-orbital of ligand HMCA to the LUMO of the oxygen atoms). A wide optical band gap of 2.25 eV is found by the solid-state UV/vis diffuse reflectance spectrum.

Preparation, Structure, Photoluminescent and Semiconductive Properties, and Theoretical Calculation of a Novel Cadmium Complex with Mixed Ligands.

A novel cadmium complex with mixed ligands [Cd(2,2'-biim)(4,4'-bipy)(H2O)(ClO4)] (ClO4)n (1) (2,2'-biim = 2,2'-biimidazole; 4,4'-bipy = 4,4'-bipyridine) has been synthesized through hydrothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique. Single-crystal X-ray diffraction analyses revealed that complex 1 crystallizes in the space group Pna21 of the orthorhombic system and exhibits a one-dimensional zigzag chain structure consisting of [Cd(2,2'-biim)(4,4'-bipy)(H2O)(ClO4)]n n+ cationic chains and isolated ClO4 - anions. Powder photoluminescent characterization reveals that complex 1 has an emission in the green region of the spectrum. Time-dependent density functional theory (TDDFT) calculation showed that the nature of the photoluminescence of complex 1 is originated from the ligand-to-ligand charge transfer (LLCT; from the HOMO of the perchlorate anions to the LUMO of the 4,4'-bipy ligand). A wide optical band gap of 3.25 eV was found by the solid-state UV/vis diffuse reflectance spectrum.

In Situ Preparation, Structure, Photoluminescence and Theoretical Study of an Unusual Bismuth Complex.

A novel bismuth photoluminescent material, (N,N'-dimethyl-2,2'-bipy)2(Bi2Cl10) · 2H2O (1) (bipy = bipyridine), with the N,N'-dimethyl-2,2'-bipy2+ moiety obtained in situ, has been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction. Compound 1 is characterized by an isolated structure, consisting of N,N'-dimethyl- 2,2'-bipy2+ cations, Bi2Cl10 4- anions and lattice water molecules. Photoluminescence experiments with solidstate samples discover that compound 1 exhibits a strong emission in the green region. Time-dependent density functional theory (TDDFT) calculation reveals that the essence of the photoluminescence of 1 can be assigned to the combination of the metal-to-ligand charge transfer (MLCT) (from the HOMO of the bismuth ion to the LUMO of the N,N'-dimethyl-2,2'-bipy2+ moiety) and the ligand-to-ligand charge transfer (LLCT) (from the HOMO of the chloride ions to the LUMO of the N,N'-dimethyl-2,2'-bipy2+ moiety).

Diaqua-bis(5-carb-oxy-2-methyl-1H-imidazole-4-carboxyl-ato-κN,O)manganese(II).

The title complex, [Mn(C(6)H(5)N(2)O(4))(2)(H(2)O)(2)], was obtained by hydro-thermal synthesis. The Mn(II) atom, which lies on an inversion centre, displays a slightly distorted octa-hedral geometry. In the crystal packing, complex mol-ecules are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds to form a three-dimensional supramolecular structure. The title complex is isostructural with the corresponding cadmium(II) complex [Nie, Wen, Wu, Liu & Liu (2007 ▶). Acta Cryst. E63, m753-m755].

{µ-6,6'-Dimeth-oxy-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}-µ-nitrato-dinitratoholmium(III)zinc(II).

In the title heteronuclear Zn(II)-Ho(III) complex (systematic name: {µ-6,6'-dimeth-oxy-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-1κ(4)O(1),O(1'),O(6),O(6'):2κ(4)O(1),N,N',O(1'))-µ-nitrato-1:2κ(2)O:O'-dinitrato-1κ(4)O,O'-holmium(III)zinc(II)), [HoZn(C(18)H(18)N(2)O(4))(NO(3))(3)], with the hexa-dentate Schiff base compartmental ligand N,N'-bis-(3-methoxy-salicyl-idene)ethyl-enediamine (H(2)L), the Ho and Zn atoms are triply bridged by two phenolate O atoms of the Schiff base ligand and one nitrate ion. The five-coordinate Zn atom is in a square-pyramidal geometry with the donor centers of two imine N atoms, two phenolate O atoms and one of the bridging nitrate O atoms. The Ho(III) center has a ninefold coordination environment of O atoms, involving the phenolate O atoms, two meth-oxy O atoms, two O atoms from two nitrate ions and one from the bridging nitrate ion. Weak inter-molecular C-H⋯O inter-actions generate a two-dimensional double-layer structure.

[Chromatographic behavior of purine derivatives on cucurbit [6] uril monorotaxane-bonded silica stationary phase by high performance liquid chromatography].

The chromatographic behavior of purine derivatives on a new cucurbit [6] uril monorotaxane-bonded silica stationary phase (CB6MRBS) was studied using high performance liquid chromatography both under normal and reversed-phase modes. A comparative study of this phase with ODS was carried out as well. The influences of methanol content, pH value and ionic strength of mobile phases were investigated in detail. The results showed that various interactions occurred between the analytes and CB6MRBS besides hydrophobic interaction under reversed-phase were different from those on ODS. According to the chromatographic analysis, the separation mechanism of multiple interactions also exists under normal phase. The CB6MRBS can provide various sites for analytes, such as the hydrophobic, hydrogen-bonding, pi-pi and dipole-dipole interactions. Separations of purine derivatives on CB6MRBS were achieved with satisfaction due to the various retention mechanisms both under reversed- and normal phase modes.