Quantum chemistry investigation on the active site of Mn-SOD

In this paper, we carried out a theoretical study on the active site structures of the Mn-SOD with ab initio Hartree–Fock SCF method, and analyzed the molecular orbital energies, charges and atomic orbital contribution to the frontier molecular orbital.     

三(2-苯并咪唑亚甲基)胺硝酸镍(Ⅱ)配合物的合成及结构

三（２－苯并咪唑亚甲基）胺简称ＮＴＢ与Ｎｉ（Ⅱ）的硝酸盐形成配合物Ｃ２８Ｈ３５Ｎ９Ｏ９Ｓ２Ｎｉ。本文报道其合成，红外光谱及晶体结构。该化合物为三斜晶系，空间Ｐ１↑－，ａ＝９．６５０（３），ｂ＝１２．７１６（２），ｃ＝１４．４３６Ａ，α＝１１．４６（２），β＝９１．６６（３），γ＝９７．５５（２）°，Ｖ＝１７１８（２）Ａ＾３，Ｚ＝２，Ｆ（０００）＝７９３，Ｄｃ＝１．４８ｇ／ｃｍ＾３，Ｍｒ＝７６４．１     

A self-assembly/disassembly two-photo ratiometric fluorogenic probe for bacteria imaging

A fluorogenic probe for bacteria imaging was reported. The binding with anionic bacterial surfaces disassembled the self-assembly probe to turn-on the fluorescence and shift pyrene monomer/excimer ratiometric signals.     

Resonance Rayleigh scattering method for the recognition and determination of double-stranded DNA using amikacin

In weakly acidic buffer medium, the interaction of amikacin with calf thymus DNA, yeast RNA and denatured DNA has been investigated by using resonance Rayleigh scattering (RRS) technique. The result shows that calf thymus DNA is capable of enhancing the RRS intensity of the amikacin, while yeast RNA and denatured DNA have very little enhancement effect. Based on the characteristics, a sensitive assay for detecting double-stranded DNA in the presence of denatured DNA and yeast RNA has been developed. The enhancement of the RRS signal is directly proportional to the concentration of double-stranded DNA in the range 0.02-12.0 μg ml⁻¹ for calf thymus DNA and its detection limit (3σ) is 2.5 ng ml⁻¹. The method shows a wide linear range and high sensitivity, and almost no interference can be observed from RNA, denatured DNA, amino acid and most of the metal ions. The trace amounts of nucleic acid in synthetic samples and practical samples are determined with satisfactory results. Therefore, the proposed method is promising for as an effect means for recognition in vivo and determination in situ of double-stranded DNA.     

Synthesis and biological activity of novel 2-(3-trifluoromethylphenoxy)-4-trifluoromethylthiazole-5-carboxamide derivatives

Novel 2-(3-trifluoromethylphenoxy)-4-trifluoromethylthiazole-5-carboxamides were designed and synthesized utilizing ethyl 3-amino-4,4,4-trifluoro-2-butenoate as a starting material via six steps. Subsequently, their biological activities were evaluated in the greenhouse. Results indicated that several compounds have some insecticidal or fungicidal activity at 600 g ai/ha and 300 g ai/ha, respectively.     

Crystal engineering of a versatile building block toward the design of novel inorganic-organic coordination architectures

Six novel inorganic-organic coordination supramolecular networks based on a versatile linking unit 4-pyridylthioacetate (pyta) and inorganic Co(II), Cu(II), Ag(I), Zn(II), Mn(II) and Pb(II) salts have been prepared in water medium and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of CoCl(2).6H(2)O with Hpyta afforded a neutral mononuclear complex [Co(pyta)(2)(H(2)O)(4)](1), which exhibits a two-dimensional (2-D) layered architecture through intermolecular O-HO interactions. Reaction of CuCl(2.2H(2)O with Hpyta yielded a neutral one-dimensional (1-D) coordination polymer [[Cu(pyta)(2)(H(2)O].0.5H(2)O](n)(2) consisting of rectangle molecular square units, which show a three-dimensional (3-D) supramolecular network through S...S and O-H...O weak interactions. However, when AgNO(3), Zn(OAc)(2).2H(2)O or MnCl(2).4H(2)O salts were used in the above self-assembled processes, the neutral 2-D coordination polymers [Ag(pyta)](n)(3), [[Zn(pyta)(2)].4H(2)O](n)(4) or [[Mn(pyta)(2)(H(2)O)]](n)(5) with different topologies were obtained, respectively. While substituting the transition metal ions used in 1-5 with Pb(OAc)(2).3H(2)O, a one-dimensional coordination polymer [Pb(pyta)(2)](n)(6), which shows a novel 2-fold interpenetrating 2-D supramolecular architecture through weak SS interactions, was isolated. It is interesting to note that the building block pyta anion exhibits different configurations and coordination modes in the solid structures of complexes 1-6. These results indicate that the versatile nature of this flexible ligand, together with the coordination preferences of the metal centers, play a critical role in construction of these novel coordination polymers or supramolecules. The spectral and thermal properties of these new materials have also been investigated.     

Exciton interactions in CdS nanocrystal aggregates in reverse micelle

Here we report the formation and spectroscopic properties of cadmium sulfide (CdS) nanocrystal systems: individual nanocrystal and CdS aggregates. The optical absorption and luminescence spectra of the aggregated CdS nanocrystals and individual nanocrystal show exciton aggregate and individual exciton characteristics. Although it is not Bose-Einstein condensation, such aggregated quantum dots (QDs) seem to supply us opportunity to study the interactions and condensation of excitons in multi-QDs system, not in the separated QDs system.     

Synthesis, crystal structure and properties of the Cu complex of a tetradentate imidazole-functionalized diazamesocyclic ligand, 1,4-bis(N-1-methylimidazol-2-yl-methyl)-1,4-diazacycloheptane

A new potential tetradentate ligand, 1,4-bis(N-1-methylimidazol-2-ylmethyl)-1,4-diazacycloheptane (l), together with its Cu^II complex [CulCl]ClO₄ (1), has been reported. The crystal structure of 1, determined by single-crystal X-ray analysis, shows that it is in chiral P2₁2₁2₁ space group. The Cu^II centre is penta-coordinated in square pyramidal geometry and the diazacycloheptane (DACH) ring adopts normal boat configuration. The most striking feature of this complex is the formation of a 3D network bridged through the C-H?Cl hydrogen bonds with the perchlorate anions in the cavities, and stabilized via π-π stacking interactions along the a-direction. The solution behaviour of 1 has been further investigated by UV/Vis and ESR techniques.