Search

Two nickel(II) complexes were synthesized and structurally as well as magnetically characterized by using two positional isomeric nitronyl nitroxide radical ligands and H3cda as co-ligand: [Ni(NIToPy)(cda)]H2O ·CH3OH ( 1) and [Ni(IM4Py)2(cda)H2O] ( 2) [NIToPy = 2-(3′-pyridinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide; IM4Py = 2-(4′-pyridinyl)-4,4,5,5-tetramethylimidazoline-l-oxyl; H3cda = 4-hydroxypyridine-2,6-dicarboxylic acid]. Single-crystal structures analyses show that both complexes have similar mononuclear structures, in which the central NiII ions are hexacoordinated with a distorted octahedral arrangement. The magnetic properties of 1 and 2 were studied, and antiferromagnetic interactions between NiII ion and radicals are observed. [ABSTRACT FROM AUTHOR]

Eu(III)–Sr(II)–K(I) and Tb(III)–Sr(II)–K(I) heterotrimetallic metal-organic frameworks with 2,4,6-pyridinetricarboxylic acid have been synthesized under hydrothermal conditions. The complexes are isomorphic and both in triclinic space groupP-1. The ligands bond with three metal ions with two coordination modes. One connects seven metal ions and the other connects eight metal ions. IR spectra, thermal analysis, and photoluminescent properties have been studied. The results display strong characteristic emissions of Eu(III) or Tb(III) ions with excitation of ultraviolet radiation. [ABSTRACT FROM PUBLISHER]

Three-dimensional silver/polyethyleneimine/alginate hydrogel beads have been prepared successfully via a facile and simple one-pot assembly method, which can be used efficiently in catalytic hydrogenation reaction of p -nitrophenol under batch and fixed-bed experiment. Polyethyleneimine is used to reduce and limit the growth of nano-silver particle and alginate microsphere is used as the catalyst carrier, leading to form well silver nanoparticles dispersion. Several characterizations were applied to the materials, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. As-prepared catalysts only spent 120 s finishing reaction at ambient temperature (20% silver load) and stable catalytic performance with high conversion percentage for p -nitrophenol about 90% at 298 K under fixed-bed condition. The relationship between concentration and time was well depicted by Pseudo-first order kinetic model. The catalytic performance for recycled catalyst remained highly efficient, and the conversion efficiency of 96.4% can be maintained after 10 cycles. [ABSTRACT FROM AUTHOR]

We successfully designed and developed a new strategy for synthesizing an energetic material, poly(3,3ʹ-bisazidomethyl oxetane) (PBAMO), by microwave assistance, which dramatically shortened the reaction time and improved the safety of the synthetic process. [ABSTRACT FROM AUTHOR]

Two novel lanthanide−sulfate compounds, [Ln 2 (SO 4 ) 3 (H 2 O) 8 ] (Ln = Tb ( 1 ) and Dy ( 2 )), have been synthesized under hydrothermal reactions. X-ray crystal structure analyses reveal that 1 and 2 are isomorphous and crystallize in monoclinic C 2 /c pace group, showing a layered structure. The layers bear a rare quasi-honeycomb metal arrangement, which is fastened by μ 3 = η 1 : η 1 : η 1 and μ 2 = η 1 : η 1 sulfates. If assigning the μ 3 = η 1 : η 1 : η 1 sulfate as a 3-connected node and the Ln 3+ ion as a 4-connected node, the network can be rationalized as a binodal (3,4)-connected V 2 O 5 topology with a Schäfli symbol of (4 2 ·6 3 ·8) (4 2 ·6). In addition, the infrared, thermogravimetric analysis and luminescent properties were also studied. Complexes 1 and 2 exhibit outstanding thermal stability and characteristic terbium and dysprosium luminescence. [ABSTRACT FROM AUTHOR]

Ni(L)2 (1) and Zn2(μ-OL)2(L)2 (2), (HL=S-benzyl-β-N-(2-bromobenzylidene) dithiocarbazate), were synthesized and characterized by elemental analysis and X-ray single-crystal diffraction analysis. 1 is a mononuclear neutral nickel(II) complex and the center nickel atom is chelated by donors of N2S2 possessing a distorted tetrahedral configuration, while in 2, the adjacent two complex molecules are linked through two O atoms to form a dimer and the center zinc atom is five-coordinate in a distorted trigonal-bipyramidal geometry. The cytotoxic activity study indicated that 2 showed potent cytotoxic activity against the human liver hepatocellular carcinoma (HepG2) cancer cell lines, with IC50 2.4±0.2μg·mL−1, which is slightly weaker than 5-fluoroacil (5-FU) (0.89±0.21μg·mL−1) as reference. A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 plasmid DNA. [ABSTRACT FROM AUTHOR]

A layer-by-layer deposition strategy was employed for the immobilization of tungstophosphoric acid (HPW) onto a pentaethylenehexamine (PEHA)-grafted ZrSBA-15 framework to a give HPW/PEHA/ZrSBA-15 composite. The resulting composite was characterized by XRD, SEM, TEM, FTIR, thermogravimetric analysis, N2 sorption, and X-ray photoelectron spectroscopy, and these methods showed that the composite was stable in polar environments. These properties were attributed to the method of preparation, which ensured that a dense and stable array of HPW was encapsulated within the pores of PEHA-modified ZrSBA-15. In the H2O2-mediated oxidation of benzyl alcohol, the 25 % HPW/PEHA/ZrSBA-15 catalyst exhibited high selectivity (>99 %) for benzaldehyde. Moreover, the oxidation reaction was performed under solvent-free conditions, and the catalyst was recycled several times with negligible loss in selectivity and conversion. This HPW-based catalyst was also efficient at selectively oxidizing other benzylic and alkyl alcohols to the corresponding aldehydes. [ABSTRACT FROM AUTHOR]