Grown-like macrocycle zinc complex derived from beta-diketone ligand for the polymerization of rac-lactide

Enolic Schiff base zinc (II) complex 1 was synthesized. XRD revealed 1 was a novel crown-like macrocycle structure consisted of hexanuclear units of (LZnEt)(6) via the coordination chelation between the Zn atom and adjacent amine nitrogen atom. Further reaction of 1 with one equivalent 2-propanol at RT produced Zn-alkoxide 2 by in situ alcoholysis. Complex 2 was used as an initiator to polymerize rac-lactide in a controlled manner to give heterotactic enriched polylactide. Factors that influenced the polymerization such as the polymerization time and the temperature as well as the monomer concentration were discussed in detail in this paper.

A zinc/p-sulfonatocalix[4]arene/phenanthroline supramolecular compound with novel (H2O)(10) water clusters

A supramolecular complex Zn-2[Cl2H8N2](2)[C28H2OS4O16][H2O](17.7) (1), has been synthesized under hydrothermal conditions, and characterized by IR spectroscopy, TG and DTA analysis, and single crystal X-ray diffraction. Unprecedented (H2O)(10) water clusters consisting of cyclic pentamer (H2O)(5) and five dangling water molecules were observed in the lattice.

Synthesis of Tributylphosphate Capped Luminescent Rare Earth Phosphate Nanocrystals in an Ionic Liquid Microemulsion

Uniform rare earth phosphate (REPO4, RE = La-Tb) nanocrystals were successfully synthesized in a properly designed TBP/[Omim]Cl/H2O (tributylphosphate/1-octyl-3-methyl-imidazolium chloride/water) microemulsion system. The phosphoryl groups anchored the TBP molecules oil the surfaces of the nanocrystals, and this made the nanocrystals easily dispersed in some imidazolium-based ILs. LaPO4:Eu3+ and CePO4:Tb3+ nanocrystals capped with TBP showed bright red and green emission under UV excitation, with enhanced emission intensity and lifetimes compared with the uncapped ones.

Water-soluble phosphate-functionalized polyfluorene as fluorescence biosensors toward cytochrome c

An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6'-phosphatehexyl)fluorene-alt-1,4-phenylene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well soluble in water with a strong blue fluorescence emission. Effect of the side chain length on fluorescence sensory properties was studied by comparing quenching efficiencies toward different quenchers of PFHPNa with a reported polymer poly(9,9-bis(3'-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPPNa), which have different side chains in length. For small molecular quenchers (methylviologen, MV2+) and meso-5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphine (TMPyP4), polymer PFHPNa had lower sensitivity due to the much longer side chain length. The positively charged metalloprotein cytochrome c could quench fluorescence of conjugated polymers via energy transfer and electron transfer.

Near infrared long lasting emission of Yb3+ and its influence on the optical storage ability of Mn2+-activated zinc borosilicate glasses

The near infrared long lasting phosphorescence of Yb3+ is observed in Yb3+ and Mn2+ codoped zinc borosilicate glasses. Compared with the glasses solely activated by Mn2+, when the Yb3+ ion is codoped, the red long lasting phosphorescence of the samples is largely improved in both brightness and persistent time but the photostimulated long lasting phosphorescence is greatly depressed. It is considered that the appearance of the phosphorescence of Yb3+ is due to the alteration of the energy transfer channel; additionally, Yb3+ also changes the trap depth of the glasses with the shallower trap predominating therefrom the red long lasting phosphorescence is improved and the photostimulated long lasting phosphorescence is degraded.

Charge carrier transporting, photoluminescent, and electroluminescent properties of zinc(II)-2-(2-hydroxyphenyl)benzothiazolate complex

Zinc(II)-2-(2-hydroxyphenyl)benzothiazolate complex is an excellent white-light-emitting material. Despite some studies devoted to this complex, no information on the real origin of the unusually broad electroluminescent (EL) emission is available. Therefore, we investigate photoluminescent and EL properties of the zinc complex. Orange phosphorescent emission at 580 nm was observed for the complex in thin film at 77 K, whereas only fluorescent emission was obtained at room temperature. Molecular orbitals, excitation energy, and emission energy of the complex were investigated using quantum chemical calculations. We fabricated the device with a structure of ITO/F16CuPc(5.5 nm)/Zn-complex/Al, where F16CuPc is hexadecafluoro copper phthalocyanine. The EL spectra varied strongly with the thickness of the emissive layer. We observed a significant change in the emission spectra with the viewing angles. Optical interference effects and light emission originating both from fluorescence and from phosphorescence can explain all of the observed phenomena, resulting in the broad light emission for the devices based on the Zn complex. We calculated the charge transfer integral and the reorganization energy to explain why the Zn complex is a better electron transporter than a hole transporter.