One Novel Three-dimensional Network Constructed from [Mn(4,4′-bip)<Subscript>2</Subscript>(OH<Subscript>2</Subscript>)<Subscript>4</Subscript>]<Superscript>2+</Superscript> Cations and DBA<Superscript>2−</Superscript> Anions via Hydrogen-bonding and π–π Interactions

Abstract One new mononuclear manganese complex of [Mn(4,4′-bip)₂(OH₂)₄](DBA) · 4H₂O (1) (4,4′-bipyridine, 4,4′-bip; H₂DBA, benzene-1,3-dicarboxylic acid) has been obtained from the hydrothermal reaction of MnCl₂ · 4H₂O, 4,4′-bipyridine and H₂DBA in the solvent of H₂O at 140 °C for 3 days, characterized by X-ray analysis, spectroscopic methods, and thermal analysis. Packing diagram shows that the three-dimensional network was formed via hydrogen bonds and strong π–π interactions. Graphical abstract One Novel Three-dimensional Network Constructed from [Mn(4,4′-bip) ₂ (OH ₂ ) ₄ ] ²⁺ Cations and DBA ²⁻ Anions via Hydrogen-bonding and π–π Interactions Ying Liu, Bao Zhang, Jian-min Dou, Da-qi Wang, Da-cheng Li, Lei Zhou One new mononuclear manganese complex of [Mn(4,4’-bip)₂(OH₂)₄](DBA) · 4H₂O (1) (4,4’-bipyridine, 4,4’-bip; H₂DBA, benzene-1, 3-dicarboxylic acid) has been obtained and haracterized by X-ray analysis, spectroscopic methods, and thermal analysis. Packing diagram shows that the three-dimensional network was formed via hydrogen bonds and strong π-π interactions.      

Synthesis and evaluation of oxovanadium(iv) complexes of Schiff-base condensates from 5-substituted-2-hydroxybenzaldehyde and 2-substituted-benzenamine as selective inhibitors of protein tyrosine phosphatase 1B

Five oxovanadium(iv) complexes, which were divided into two groups, [V(IV)O(bhbb, nhbb)(H(2)O)(2)] (tridentate ligands: H(2)bhbb = 2-(5-bromo-2-hydroxylbenzylideneamino)benzoic acid, ; H(2)nhbb = 2-(5-nitro-2-hydroxylbenzylideneamino)benzoic acid, ) and [V(IV)O(cpmp, bpmp, npmp)(2)] (bidentate ligands: Hcpmp = 4-chloro-2-((phenylimino)methyl)phenol, ; Hbpmp = 4-bromo-2-((phenylimino)methyl)phenol, ; Hnpmp = 4-nitro-2-((phenylimino)methyl) phenol, ) have been prepared and characterized by elemental analysis, infrared, UV-visible and electrospray ionization mass spectrometry. The coordination in [V(IV)O(bhbb)(H(2)O)(2)] () was confirmed by X-ray crystal structure analysis. The oxidation state of V(iv) with d(1) configuration in was confirmed by EPR. The speciation of VO/H(2)bhbb in methanol-aqueous solution was investigated by potentiometric pH titrations. The result indicated that the main species were [V(IV)O(bhbb)(OH)](-) and [V(IV)O(bhbb)(OH)(2)](2-) at the pH range 7.0-7.4. The structure-activity relationship of the vanadium complexes in inhibiting protein tyrosine phosphatases (protein tyrosine phosphatase 1B, PTP1B; T-cell protein tyrosine phosphatase, TCPTP; megakaryocyte protein-tyrosine phosphatase, PTP-MEG2; Src homology phosphatase 1, SHP-1 and Src homology phosphatase 2, SHP-2) was investigated. The oxovanadium(iv) complexes were potent inhibitors of PTP1B, TCPTP, PTP-MEG2, SHP-1 and SHP-2, but exhibited different inhibitory abilities over different PTPs. Complexes and displayed better selectivity to PTP1B over the other four PTPs. Kinetic data showed that complex inhibited PTP1B, TCPTP and SHP-1 with a noncompetitive inhibition mode, but a classical competitive inhibition mode for PTP-MEG2 and SHP-2. The results demonstrated that both the structures of vanadium complexes and the conformations of PTPs influenced PTP inhibition activity. The proper modification of the organic ligand moieties may result in screening potent and selective vanadium-based PTP1B inhibitors.     

A novel PtII–dibenzo‐18‐crown‐6 (DB18C6) complex

The novel Pt^II–dibenzo‐18‐crown‐6 (DB18C6) title complex, μ‐[tetrakis­(thio­cyanato‐S)­platinum(II)]‐N:N′‐bis{[2,5,8,­15,18,21‐hexa­oxa­tri­cyclo­[20.4.0.1^9,14]­hexa­cosa‐1(22),9(14),10,12,23,25‐hexaene‐κ⁶O]­potassium(I)}, [K(C₂₀H₂₄O₆)]₂[Pt(SCN)₄], has been isolated and characterized by X‐ray diffraction analysis. The structure analysis shows that the complex displays a quasi‐one‐dimensional infinite chain of two [K(DB18C6)]⁺ complex cations and a [Pt(SCN)₄]^2? anion, bridged by K⁺?π interactions between adjacent [K(DB18C6)]⁺ units.     

Fabrication of one-dimensional Fe3O4/P(GMA-DVB) nanochains by magnetic-field-induced precipitation polymerization

One-dimensional (1D) magnetic Fe(3)O(4)/P(GMA-DVB) peapod-like nanochains have been successfully synthesized by magnetic-field-induced precipitation polymerization using Fe(3)O(4) as building blocks and P(GMA-DVB) as linker. The Fe(3)O(4) microspheres without surface modification can be arranged with the direction of the external magnetic field in a line via the dipolar interaction between Fe(3)O(4) microspheres and linked permanently via P(GMA-DVB) coating during precipitation polymerization. The length of peapod-like nanochains can be controlled by magnetic field intensity, and the thickness of polymer shell can be tuned by the amount of monomers. Magnetic measurement revealed that these 1D peapod-like nanochains showed highly magnetic sensitivity. In the presence of magnetic field, 1D magnetic Fe(3)O(4)/P(GMA-DVB) peapod-like nanochains can be oriented and aligned along the direction of external magnetic field.     

Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

Nuclear magnetic resonance spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. (1)H and (7)Li spin-lattice relaxation times (T(1)) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T(1) values along with the presence of minima in T(1) as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though lithium hopping is about ten times slower than the segmental motion. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and quasi-elastic neutron scattering experiments.     

Local Well-posedness and Blow Up Criterion for the Inviscid Boussinesq System in Hölder Spaces

We prove the local in time existence and a blow up criterion of solution in the Hölder spaces for the inviscid Boussinesq system in R^N, N≥ 2, under the assumptions that the initial values θ_0, μ_0∈C^r, with 1< r≠ 2.     

Zinc Stannate Nanostructures for Energy Conversion

To date,ternary metal oxide semiconductor materials have attracted extensive attention worldwide due to their unique optoelectronic properties.As a classical ternary oxide,Zn2SnO4 is featured with the high electron mobility,wide band gap,negligible visible light absorption and tailorable electronic band structures.Thus,it is an ideal material for practical use in solar cells,lithium batteries,sensors,and photo-catalysts.In this review,we summarize the recent research progress of this material with the focus on the synthesis methods,nanostructures,and the resulting effects on the crystal structure,optical properties,and photoelectrochemical properties.Moreover,their potential applications in different devices are highlighted and carefully discussed.     

High surface plasmon resonance sensitivity enabled by optical disks

We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (～1600 nm per refractive index unit) is achievable by CDs.