Influence of Saturated or Unsaturated Dicarboxylate Anions on Magnetism of Co(Ⅱ) and Cu(Ⅱ) Hydroxide-based Spin Layers

In the context of molecule-based magnets, a driving force is the design of complex systems, combining molecular units used as building blocks, to favor bulk magnetic properties. Such a strategy has been successfully explored for the preparation of both purely organic as well as purely inorganic magnets. A step forward, to achieve multifunctional solids, is the combination of both the molecular and inorganic chemistries to build hybrid organic/inorganic materials. Clearly, such an approach is very appealing for the design of novel 3d materials exhibiting improved properties with respect to those of the individual networks.     

Pt(Ⅱ), Pd(Ⅱ) and Ni(Ⅱ) Complexes Binding to the N(7) Position of Guanine: Influence on the Guanine and Watson-crick GC Base Pair

Comprehensive ab initio calculations were performed on the coordination of Pt(Ⅱ),Pd(Ⅱ) and Ni(Ⅱ) adducts to the N(7) of guanine and guanine-cytosine (GC) base pair at the DFT level. The fully optimized geometries of the metal complexes were obtained and the stabilization energies of the interaction between metal adducts and nucleobase were calculated with B3LYP method by using 6-31^* basis set for the light atom. While the effective core potential (ECP) is used for metal cation. The results show that both cispalladium and cisnickel cause similar geometric changes of the base pair as cisplatin. For the coordination of metal adducts to guanine, platinum adduct possesses the highest stabilization energy; but the interaction between metal-guanine and cytosine for nickel is larger than that for platinum and palladium. It is worthy to note that hydrolysis effect can also cause significant changes in H-bonds.     

Influence of Isosorbide on Glass‐Transition Temperature and Crystallinity of Poly(butylene terephthalate)

Copolyesters of isosorbide and 1,4‐butane diol were prepared by Ti(OBu)₄‐catalyzed transesterifications with dimethyl terephthalate in bulk at temperatures up to 250°C. The content of isosorbide was considerably lower than expected from the feed ratio and the molar masses were low, so that no DSC measurements were conducted. Copolycondensations of isosorbide and 1,4‐butane diol with terephthaloyl chloride were either performed in dichloromethane at 40°C or in toluene at 100°C. The second method gave the higher molar masses. However, both series of polycondensations had the content of isosorbide roughly paralleled the feed ratios in common. The DSC measurements revealed that even 6 mol% of isosorbide is sufficient to raise the glass‐transition temperature (T_g) by 10–12°C (up to 55°C). With 50 mol% of isosorbide, the T_g reaches 100°C. Yet, incorporation of isosorbide also reduces the melting temperature T_m and the degree of crystallinity, and a mol percentage above 30% prevents crystallization completely. In summary, incorporation of isosorbide allows for fine‐tuning of T_g and T_m of poly(butylene terephthalate) over a wide range.     

Syntheses and Anti-lung Cancer Activities of Zn(Ⅱ) and Cu(Ⅱ) Complexes Based on Triazole and Tetrazole,respectively

The reactions of 4H-1,2,4-triazole(Htrz) with ZnCl_2, 1H-tetrazole(Htez) and Cu(NO_3)2·6H_2O afford two novel coordination polymers respectively, {[Zn_2(trz)_2(ox)](H_2O)_3}n(1) and {[Cu_3(tez)_3(OH)_2(H_2O)_2](NO_3)(DMF)_4}_n(2)(H_2ox =(COOH_)2, DMF = N,N-dimethylformamide). 1 shows 1D channels along the a axis filled with water molecules and 2 features a 2D bi-layered framework based on trinuclear Cu(II) units bridged by two μ3-OH groups. In addition, in vitro antitumor activities of compounds 1 and 2 on four human lung cancer cells(16HBE, NCI-H1299, NCI-H460 and NCI-H292) were further determined.     

Impact of Zn(Ⅱ) Ions on Crystallization and Thermal Properties of Poly(lactic acid)

The issues of low crystallinity and slow crystallization rate of poly(lactic acid) (PLA) have been widely addressed. In this work, we find that doping PLA with Zn(Ⅱ) ions can speed up the process of crystallization of PLA. Three kinds of Zn(Ⅱ) salts (ZnCl\begin{document}$ _2 $\end{document}, ZnSt and ZnOAc) were tested in comparison with some other ions such as Mg(Ⅱ) and Ca(Ⅱ). The increased crystallinity and crystallization rate of PLA doping with Zn(Ⅱ) are reflected in FT-IR and variable temperature Raman spectroscopy. The crystallinity is further confirmed or measured with differential scanning calorimetry and X-ray diffraction. The crystallinity rate of the PLA/ZnSt-0.4 wt% material can reach 22.46% and the crystallinity rate of the PLA/ZnOAc-0.4 wt% material can reach 24.83%, as measured with differential scanning calorimetry.     

Sorption–Desorption of Copper and Strontium Ions by the Soil. The Influence of Microorganisms on the State of Metals

Sorption of heavy metal (copper and strontium) ions by the meadow chernozem and grey forest soils differing in the content of organic substance was described using the Langmuir equation. The analysis of characteristic sorption coefficients demonstrated that copper possesses the enhanced affinity for the studied soil samples compared to strontium. Maximal values of the sorption of copper (0.085 mmol/g) and strontium (0.045 mmol/g) obtained for the colloidal fraction of meadow chernozem soil (particle diameter d < 1 m) are approximately 1.5 times larger than for the same fraction of grey forest soil; this ratio remains almost the same even when using the coarser fraction (d < 50 m). It was established that up to 90% of metal ions could be present in the soil in an immobile form. An increase in the concentration of heavy metal ions in the soil causes their redistribution between the components of absorbing soil complex and an increase in the fraction of metal in mobile forms (water-soluble, exchange, soluble in weakly acidic medium). Upon the microbiological treatment (bioleaching in the suspension variant) of the soils containing copper or strontium ions, the total content of metal, including its mobile forms, decreases by an order of magnitude.     

Influence of γ-radiation on iodine-doped poly (3-pentylthiophene)

The influence of -radiation on iodinedoped poly (3-pentylthiophene) has been studied. Doping accompanied by -radiation brings about a decrease of iodine release rate. An increased dopant concentration in the poly (3-pentylthiophene) leads to an increased conductivity, which may be accounted for by the formation of bipolarons in the irradiated and doped samples.     

Theoretical Studies on theStructures and Reactivity of Stannylenoides(Ⅱ)——Structures and Isomerization of Stannylenoid H2SnNaF

The structures of stannylenoid HzSnNaF have been studied using RHF/3-21G and RHF/3-21G^* gradient method.     

Model Study of Basin Soil Loss (BSL) in the Loess Plateau of China (Ⅱ)

According to the influence of underlayer factor upon the basin erosion and in the support of Geographic Information System (GIS) of Loess Plateau(LPIS), the Gushanchuan Basin is divided into several regions with different erosion intensity. Correlating them to the BSL quantity, the complete soil loss model is established. By using this model, the soil loss quantity of the whole basin as well as each erosion intensity region can be estimated.     

Influence of the Substituents on Imino-aryl Ring of Mono(imino)pyrrole-Ni~(Ⅱ) Complexes to Their Ethylene Polymerization Catalytic Performance

In order to study the influence of substituents on imino-aryl rings of mono(imino)pyrrole-transition metal complexes to their ethylene polymerization performance, a series of mono(imine)pyrroles(L1-L3) were synthesized by microwave irradiation from 2-acetylpyrrole and a series of 2,6-position disubstituted anilines(substituent: H, Me, Et). A simplified synthetic method was introduced to prepare the corresponding nickel complexes NiL_2(1～3) with direct condensation of mono(imine)pyrrole ligands and nickel dichloride. All the compounds were fully characterized by 1 H NMR, IR, EA, MS, and X-ray crystal diffraction. Ligand L3(C_(16)H_(20)N_2, Mr = 240.34) belongs to the triclinic system, space group P1, with a = 7.9606(19), b = 9.028(2), c = 11.205(3) ?, the final R = 0.0606 and wR = 0.1875. Complex 3(C_(32)H_(38)N_4Ni, Mr = 537.37) belongs to the monoclinic system, space group C2/c with a = 19.811(3), b = 11.262(2), c = 26.004(4) ?, the final R = 0.0388 and wR = 0.1020. The crystal structures indicated that all the Ni~(Ⅱ) complexes have similar tetra-coordinated geometries, in which the ligand chelated to the center nickel with a 2:1 molar ratio. Catalytic properties of the Ni~(Ⅱ) complexes for ethylene polymerization were systematically investigated, and the results showed a regular increase of catalytic activities with steric hindrance of the substituents on the imino-aryl ring of Ni~(Ⅱ) complexes.     

Synthesis and Characterization of Dipeptide Schiff Base Complexes of Copper(Ⅱ), Zinc(Ⅱ), Nickel(Ⅱ) and Cobalt(Ⅱ)

N-saliCylidenchnoacidcomplexesInayserveasmodelsfOrN-bodoXylidenedoacidcomp1exSystmschcharebelieVedtObetheintermediatesinthetranboIlationprocessl'l.ThecoordinaionOfametaJiontosuchSchiffbasesstabilizestheazomethine1inkag,underconditionsthatwouldothendsepromotebondcleaVag[2-5].Inaddition,thecomplexesOftalnoeddScAfbasesareconsideredtobeanewldndOfpoentialanhbactrialandanhcanceragentsl6].However,littleattentionhasbeengiventoSystemsinwhchtheScusbasesarederivedfromsimPlepePtides.ThispoprrePO…     

Influence of Backbone and Axial Substituent of Catalyst on α-Imino-ketone Nickel Mediated Ethylene (Co)Polymerization

Chinese Journal of Polymer Science - The α-imino-ketone nickel catalyst is an emerging versatile platform that is easy to prepare and allows for the production of branched high molecular...     

Dimerization of Propylene by Nickel (Ⅱ) and Cobalt (Ⅱ) Catalysts Based on Bidentate Nitrogen-phosphino Chelating Ligands

The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ) complexes containing N-P bidentate ligands was studied in combination with organoaluminum co-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the nature of precursors in terms of ligand backbone and metal center were investigated. The results indicated that precursor I (N,N-dimethyl-2-(diphenylphosphino)aniline nickel (Ⅱ) dichloride) exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3Al2Cl3, whereas low productivity by its cobalt analogues was observed under identical reaction conditions.     

The Influence of β-Diketones on the Hydrolysis and Growth of Particles from Zirconium(IV) n-Propoxide

The influence of low ligand/Zr mole ratios ( = 0–0.1) on the hydrolysis and growth of oligomers from Zr(O ⁿ Pr)₄ modified with a series of -diketones (trifluoroacetylacetone, hexafluoroacetylacetone, benzoylacetone, dibenzoylmethane and dipivaloylmethane), and their subsequent aggregation to form uniform, dense spheres, has been investigated by light scattering and turbidometry. The addition of -diketones results in a large increase in the induction time, t _i (reduction in hydrolysis/condensation rates). A remarkable feature of the data is the dramatic reductions in rate observed even when a maximum of one in forty Zr–OR bonds have been replaced by the -diketone and are no longer available for hydrolysis or further condensation. The largest effect is observed with dibenzoylmethane, which increases t _i by a factor of 26 relative to acetylacetone.A mechanism rationalising the origin of the effect is discussed, which involves segregation of the -diketone ligands on the surface of the growing particle, with subsequent particle growth restricted to those sites not occupied by the chelating ligands.     

Syntheses,Crystal Structures and DNA-Binding Properties of Zn(Ⅱ)and Mn(Ⅱ)Complexes Based on Imidazole Derivatives and Carboxylic Acid

Complexes[Zn(pbm)(5-hip)3](1),[Zn(pbm)(5-nip)3](2),[Mn(pbm)(H3btc)2(H2O)](3)and[Mn(pbm)(5-nip)3](4),where H2HIPA=5-hydroxyisophthalic acid,H2nip=5-nitroisophtha...     

Oxidized Hemithioindigo Photoswitches—Influence of Oxidation State on (Photo)physical and Photochemical Properties

The photophysical and photochemical properties of sulfoxide and sulfone derivatives of hemithioindigo photoswitches are scrutinized and compared to the unoxidized parent chromophores. Oxidation results in significantly blue-shifted absorptions and mostly reduction of photochromism while thermal stabilities of individual isomers remain largely unaltered. Effective photoswitching takes place at shorter wavelengths compared to parent hemithioindigos and high isomeric yields can be obtained reversibly in the respective photostationary states. Reversible solid-state photoswitching is observed for a twisted sulfone derivative accompanied by visible color changes. These results establish oxidized hemithioindigo photoswitches as promising and versatile tools for robust light-control of molecular behavior for a wide range of applications.     

Syntheses,Crystal Structures and Properties of Mn(Ⅱ) and Co(Ⅱ) Coordination Complexes Based on 1,10-Phenanthroline Derivative

Two new coordination complexes[Mn(L)₂(DNSA)](1) and[Co(L)(1,4-bdc)]_n (2) have been achieved under hydrothermal conditions (H₂DNSA=3,5-dinitro-salicylic acid,1,4-bdc=1,4-benzenedicarboxylic acid and L=2-(2-fluoro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline).1 crystallizes in monoclinic,space group P2_1/c with a=15.871(3),b=17.274(4),c=16.078(3)A,β=113.03(3)^o,V=4056.6(16)A³,Z=4,C₄₅H₂₂Cl₂F₂Mn N₁₀O₇,M_r=978.57,D_c=1.602 g/cm³,F(000)=1980,μ(Mo Ka)=0.536 mm^–1,R=0.0437 and w R=0.1065.2 belongs to the monoclinic system,space group C2/c with a=14.665(2),b=30.856(4),c=11.237(2)A,β=111.166(2)^o,V=4742.0(12)A³,Z=8,C₂₇H₁₄Cl Co FN₄O₄,M_r=517.80,D_c=1.602 g/cm³,F(000)=2312,μ(Mo Ka)=0.889 mm^–1,R=0.0364 and w R=0.0862.The central Mn(II) ion in 1 is six-coordinated by four nitrogen atoms from two L ligands and two oxygen atoms from one DNSA anion.In 2,the two kinds of 1,4-bdc ligands link neighboring Co(II) atoms to yield a two-dimensional layer structure.The luminescence of 1 has been studied in detail.Moreover,thermal behaviors of 1 and 2 are also investigated.     

Influence of ethanol and ultrasound on drying,bioactive compounds,and antioxidant activity of strawberries (Fragaria × ananassa)

This study aimed to evaluate the use of ethanol (ET) and ultrasound (US) in convective drying of strawberry slices, as well as the effect on physicochemical, bioactive, and antioxidant parameters. For this, strawberry slices with a thickness of 0.005 m were pretreated with ET (in different volume fractions), US, and a combination of both. Drying kinetics were performed for control strawberry slices (without ET and US) and pretreated with 50% ethanol (ET50), 50% ethanol and ultrasonic (ET50US), 100% ethanol (ET100), and 100% ethanol and ultrasonic (ET100US) at a temperature of 60 °C. Empirical and diffusive models were fitted to the experimental data to describe the drying kinetics, and the fresh and dried slices were analyzed according to the parameters of water activity (aw), water content, total phenolic compounds (TPC), total anthocyanins (ATS), vitamin C and antioxidant activity (AA) (ABTS?+, DPPH?, and FRAP). The use of the ET100US combination provided an increase in the moisture transport process, higher drying rate, shorter process time (570 min), and reduction of a_w to a safe value (a_w <0.5), however, it sharply degraded the TPC, ATS, and AA. The ET50US pre-treatment even with a drying time of 690 min was the most efficient, since the values of TPC, ATS, and vitamin C suffered smaller reductions, where the AA varied in only 10.32%, 13.78% and 6.54% for the methods ABTS?+, DPPH?, and FRAP, respectively when compared to fresh strawberry. In this sense, it can be stated that the pre-treatment with 50% ethanol and ultrasound (ET50US) showed less reduction in the degradation of bioactive and antioxidant properties, and in the minimization of drying time for strawberry slices.     

Synthesis of Polymer-Bonded Carbonyl Ruthenium (Ⅱ) and Osmium (Ⅱ) Porphyrins

Studyonmetalloporphyrincomplexesusedasenzymemodelcatalyzingtheoxidationofalkaneandepoxidationofalkeneiscurrentlyaveryactiveresearchfieldl.ThereactivityofrutheniumporphyrincomplexeswasusedasoxidationcatalystsbecausetheirrelationstocytochromeP-450haveb...