Real-time photovoltaic parameters assessment of carbon quantum dots showing strong blue emission

Carbon QD showing bright blue fluorescence aid in improving the photovoltaic parameters in a co-sensitized solar cell. Time-dependent I–V analysis revealed the real-time functioning of the device.

N,S Co-Doped Graphene Quantum Dots for Detection of Riboflavin and Cell Imaging

Graphene quantum dots (GQDs) have been extensively used in biosensors and bioimaging. Heteroatom-doped GQDs can regulate material properties and endow them to improve structural and physicochemical properties. In this work, N,S-GQDs were prepared through a high-temperature pyrolysis method using L-cysteine and citric acid as the precursors. The morphology and structure of nanocomposites were identified by TEM, X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), and FTIR. The as-prepared N,S-GQDs show bright blue fluorescence with satisfactory fluorescence quantum yield. N,S-GQDs display significant response to riboflavin, achieving a low detection limit of 27[Formula: see text]nM. The reaction of N,S-GQDs to riboflavin is mainly governed by static quenching. The detection of riboflavin in real samples has been performed to demonstrate its practical application. The obtained N,S-GQDs have low cytotoxicity and have been applied successfully in cell imaging.

Enantioselective construction of six- and seven-membered triorgano-substituted silicon-stereogenic heterocycles

The exploitation of chirality at silicon in asymmetric catalysis is one of the most intriguing and challenging tasks in synthetic chemistry. In particular, construction of enantioenriched mediem-sized silicon-stereogenic heterocycles is highly attractive, given the increasing demand for the synthesis of novel functional-materials-oriented silicon-bridged compounds. Here, we report a rhodium-catalyzed enantioselective construction of six- and seven-membered triorgano-substituted silicon-stereogenic heterocycles. This process undergoes a direct dehydrogenative C−H silylation, giving access to a wide range of triorgano-substituted silicon-stereogenic heterocycles in good to excellent yields and enantioselectivities, that significantly enlarge the chemical space of the silicon-centered chiral molecules. Further elaboration of the chiral monohydrosilane product delivers various corresponding tetraorgano-substituted silicon-stereogenic heterocycles without the loss of enantiopurity. These silicon-bridged heterocycles exhibit bright blue fluorescence, which would have potential application prospects in organic optoelectronic materials.

Enantioselective Construction of Six- and Seven-Membered Triorgano-Substituted Silicon-Stereogenic Heterocycles

A rhodium-catalyzed enantioselective construction of six- and seven-membered triorgano-substituted silicon-stereogenic heterocycles is developed. This process undergoes a direct dehydrogenative C−H silylation, giving access to a wide range of novel triorgano-substituted silicon-stereogenic heterocycles in good to excellent yields and enantioselectivities, that significantly enlarged the chemical space of the silicon-centered chiral molecules. Further elaboration of the chiral monohydrosilane product delivered various corresponding tetraorgano-substituted silicon-stereogenic heterocycles without the loss of enantiopurity. These novel silicon-bridged heterocycles exhibit bright blue fluorescence, which would have potential application prospects in organic optoelectronic materials.

Fluorescent and Mechanical Properties of Silicon Quantum Dots Modified Sodium Alginate-Carboxymethylcellulose Sodium Nanocomposite Bio-Polymer Films

Highly luminescent silicon quantum dots (SiQDs) were prepared via one-pot hydrothermal route. Furthermore, the optimal synthetic conditions, dependence of the emission spectrum on the excitation wavelength and fluorescent stability of SiQDs were investigated by fluorescence spectroscopy. SiQDs exhibited bright blue fluorescence, and photoluminescence (PL) lifetime is 10.8 ns when excited at 325 nm. The small-sized SiQDs (~3.3 nm) possessed uniform particle size, crystal lattice spacing of 0.31 nm and silicon (111), (220) crystal planes. Luminescent SiQDs/sodium alginate (SA)-carboxymethylcellulose sodium (CMC) nanocomposite bio-polymer films were successfully fabricated by incorporating SiQDs into the SA-CMC matrix. Meanwhile, SiQDs not only impart strong fluorescence to the polymer, but also make the composite films have favorable toughness.

Alkaline-earth and aminonicotinate based coordination polymers with combined fluorescence/long-lasting phosphorescence and metal ion sensing response

Alkaline-earth and aminonicotinate based CPs exhibit green long lasting phosphorescence and bright blue fluorescence responsive to metal ions.

Touch-sensitive mechanoluminescence crystals comprising a simple purely organic molecule emit bright blue fluorescence regardless of crystallization methods

Simple N-phenylcarbazole can readily form highly active mechanoluminescence crystals and emit bright blue fluorescence upon gentle grinding.

A twofold interpenetrating three-dimensional heterometallic metal–organic framework with pcu topology based on 2-methylbiphenyl-4,4′-dicarboxylic acid

The 2-methylbiphenyl-4,4′-dicarboxylate (mbpdc2−) ligand has versatile coordination modes and can be used to construct multinuclear structures. Despite this, reports of the synthesis of coordination complexes involving this ligand are scarce. The title compound, poly[[triaquadi-μ3-hydroxido-hexakis(μ4-2-methylbiphenyl-4,4′-dicarboxylato)calcium(II)hexazinc(II)] monohydrate], {[CaZn6(C15H10O4)6(OH)2(H2O)3]·H2O} n , has been prepared by the hydrothermal assembly of Zn(NO3)2·6H2O, CaCl2 and 2-methylbiphenyl-4,4′-dicarboxylic acid. Two ZnII atoms adopt a four-coordinated distorted tetrahedral geometry by bonding to three O atoms from three different 2-methylbiphenyl-4,4′-dicarboxylate (mbpdc2−) dianionic ligands and one bridging hydroxide O atom. For the remaining ZnII atom, a five-coordinate environment is completed half the time by one carboxylate O atom, and then the same carboxylate O atom and an aqua O atom are present the other half of the time, giving a six-coordinate environment. The CaII atom is coordinated by six O atoms to give an octahedral coordination geometry. The supramolecular secondary building unit (SBU) is a hamburger-like heptanuclear unit (Zn6CaO30) and these units are interconnected through mbpdc2− carboxylate groups to generate a three-dimensional framework with the pcu topology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K. The excitation and luminescence data showed the emission of a bright-blue fluorescence.

A hydrostable and twofold interpenetrating three-dimensional zinc–organic framework with rob topology based on 4,4′-oxydibenzoate and 3,3′-dimethyl-4,4′-bipyridine ligands

Metal–organic frameworks (MOFs) are a new class of porous materials that have received widespread attention due to their potential applications in gas storage and/or separation, catalysis, luminescence, and so on. The title compound, poly[[(μ2-3,3′-dimethyl-4,4′-bipyridine-κ2N:N′)bis(μ4-4,4′-oxydibenzoato-κ4O:O′:O′′:O′′′)dizinc] tetrahydrate], {[Zn2(C14H8O5)2(C12H12N2)]·4H2O}n, has been prepared by the solvothermal assembly of Zn(NO3)2·6H2O, 4,4′-oxydi(benzoic acid) and 3,3′-dimethyl-4,4′-bipyridine. The two ZnIIatoms adopt the same five-coordinated distorted square-pyramidal geometry (i.e.ZnO4N), bonding to four O atoms from four different 4,4′-oxydibenzoate (oba) ligands and one N atom from a 3,3′-dimethyl-4,4′-bipyridine (dmbpy) ligand. The supramolecular secondary building unit (SBU) is a paddle-wheel [Zn2(COO)4] unit and these units are linked by oba ligands within the layer to form a two-dimensional net parallel to thebaxis, with the dmbpy ligands pointing alternately up and down, which is further extended by dmbpy ligands to form a three-dimensional framework withrobtopology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K and is stable in aqueous solutions in the pH range 5–9. Excitation and luminescence data observed at room temperature show that it emits a bright-blue fluorescence.

A Zn based coordination polymer exhibiting long-lasting phosphorescence

A coordination polymer consisting of Zn and 6-aminoisonicotinate shows an initial bright blue fluorescence that turns into persistent green phosphorescence.