Synthesis,Crystal Structure and Biological Activities of Novel Di-n-butyl Tin Di-carboxylate

A novel macrocyclic complex 2{[（n-Bu2Sn）4O2-L2]2DMF} was synthesized by the reaction of 4-（1,2- dithioethylene）methylene-3,5-disoxo-1,6-heptadiene-1,7-dis-（o-formy~）-dis-p-phenoxyacetic acid（LH2, compound 1） with di-n-butyltin oxide. Compound 1 and complex 2 were characterized by elemental analysis, FTIR spectroscopy, and ~H NMR spectroscopy. The crystal structure of complex 2 was determined by single crystal X-ray diffraction analysis. There are two crystallographic independent molecules in complex 2, and each molecule structure is centro-symmetric and features a central rhombus cyclic Bu4Sn2O2 unit with two exocyclic Sn atoms linked at the O atoms of the four-membered ring. In molecule A, the four Sn atoms are five-coordinated. However, in molecule B, the four Sn atoms have two different coordination geometries, the endocyclic Sn atoms are five-coordinated and the exocyclic Sn atoms are four-coordinated. The dicarboxylate ligands in molecules A and B bridge exocylic or endocyclic tin atoms, forming two macroheterocycles with 26 atoms. Pilot studies have indicated that complex 2 has good anti- bacterial and antitumour activities.

Simultaneous quantification of prodrug oseltamivir and its metabolite oseltamivir carboxylate in human plasma by LC-MS/MS to support a bioequivalence study

A simple, precise and rapid liquid chromatography-tandem mass spectrometry （LC-MS/MS） method has been developed and validated for the simultaneous determination of oseltamivir and oseltamivir carboxylate, a neuraminidase inhibitor, using their deuterated analogs as internal standards （ISs）. The method involved solid phase extraction of the analytes and ISs from 200 μL human plasma with no reconstitution and drying steps. The chromatographic separation was achieved on a Symmetry C18 （100 mm × 4.6 mm, 5 μm） column using 10 mM ammonium formate and acetonitrile （30：70, v/v） as the mobile phase in a run time of 2.0 min. Quantitation of analytes and ISs were done by multiple reaction monitoring on a triple quadrupole mass spectrometer in the positive ionization mode. The linearity of the method was established in the concentration range of 0.5-200 ng/mL and 2.0-800 ng/mL for oseltamivir and oseltamivir carboxylate respectively. The mean extraction recovery for oseltamivir （94.4%） and oseltamivir carboxylate （92.7%） from spiked plasma samples was consistent and reproducible. The application of this method was demonstratedby a bioequivalence study in 42 healthy Indian subjects with 75 mg oseltamivir phosphate capsules. The assay reproducibility was established by reanalysis of 151 incurred subject samples.

Dispersion of Co-poly Carboxylate Superplasticizer Containing Poiyether Side Chain

Free radical co-polymerization was employed to synthesize co-poly carboxylate (PC) superplasticizers with different amount of carboxyl and methyl polyethylene glycol (MPEG) side chain.Dispersion ability and retention of PC were compared with one another. The results show that increase of side chain is advantageous to dispersion, but it decreases when amount of MPEG is beyond a certain value which is different with the proportion of carboxyl. If the amount of carboxyl increases, the influence of side chain in copolymer on dispersion diminishes. Polyether side chain is advantageous to retention. And the author explained the mechanism of PC using the theory of steric repulsive force.

Influence of Polycarboxylate Superplasticizer on Rheological Behavior in Cement Paste

Molecular structures of polycarboxylate（PCE） superplasticizer significantly affect the rheological properties of cement paste. Consequently, we employed self-synthesized PCE copolymers with different carboxylic densities to investigate their influence on the rheological behavior of cement paste. Three typical rheological models were applied to analyze the rheological properties, including Power-law model, Bingham model as well as Herschel-Buikley model. In addition, the thixotropical performances of cement paste in the presence of PCE with different carboxylic densities were investigated. The results show that the carboxylic density of PCE greatly influences the dispersing performance of PCE superplasticizers. As carboxylic density increases, the dispersing capability of PCE improves, and P（PEG1-AA6） possesses the strongest dispersing capability, the initial fluidity and 1 h fluidity of cement paste are both the highest, and cement paste has the lowest viscosity and the smallest hysteresis loop.

PREPARATION,IDENTIFICATION AND INTERFACIAL ACTIVITIES OF PETROLEUM CARBOXYLATE AS SURFACTANT FOR CHEMICAL FLOODING

Petroleum carboxylate that may be suitable for tertiary oil recovery have been produced inexpensively from the fractions of Daqing crude oil by a two step process.The feed stock was first oxidized in the vapor phase,followed by reaction of the oxidized products with sodium hydroxide.Dilute solutions of sodium carboxylates were produced and show ultralow(10^(-2)mN/m)interfacial tensions(IFTs)against a variety of hydrocarbons with a wide range of ACN(Alkane Carbon Number).Infrared spectroscopy was used to identify the functional groups in the oxidized and the saponified products.

Influence of ligand architecture on the structure of coordination centre in dimeric europium carboxylates with 1,10-phenanthroline

Methods of optical spectroscopy and X-ray crystallography data were used to examine the effect of architecture of carboxylate anions on structure of the Eu3＋ coordination centre in europium earboxylates with 1,10-phenanthroline Eu（RCOO）3·Phen. Luminescence spectra of europium acetate, nitropropionate, benzoate, naphthylcarboxylates, phenylacetates, phenoxyacetate, triphenylpropionate were investigated. A few of europium carboxylates with 2,2＇-bipyridine Eu（RCOO）3·Bpy and europium salts Eu（RCOO）3·nH2O were also studied. Vibrational IR and Raman spectra of phenylacetate family were analyzed. The crystal structure of nitropropionate Eu（NO2C2H4COO）3·Phen was solved by X-my diffraction method. The predominant influence of steric hindrances on Eu^3＋ coordination centre was observed at increase of the size of aromatic flagment of carboxylate anions. It was demonstrated, that introduction of the methylene bridges between the carboxylic group and aromatic rings of ligand weakens the effect of steric factor.

INTERACTION OF COMPONENTS IN PETROLEUM CARBOXYLATE/ALKALINE/HYDROLYZED POLYACRYLAMIDE FLOODING SYSTEM

The IFTs(Interfacial tension)of petroleum carboxylate/alkaline/HPAM(Hydrolyzed polyacrylamide)flooding system with Daing crude oil and the effects of petroleum carboxylate and alkaline on viscoaity of HPAM solution were studied.There exists remarkable synergism between HPAM and petroleum carboxylate,and the introduction of HPAM into petroleum carboxylate/alka- line system leads the lowering of IFTs against Daqing crude oil,The introduction of petroleum carboxylate into solution of HPAM also leads the decreasing of viscosity,but the extent of viscosity decreasing is much lower than that caused by inorganic salts such as NaCl and CaCl_2.

Quantum chemical descriptors based QSAR modeling of neodymium carboxylate catalysts for coordination polymerization of isoprene

Based on the quantum chemical descriptors and the activities for isoprene polymerization of 12 neodymium carboxylates obtained by authors’earlier work,statistical analysis of data was made and a QSAR model correlating the quantum chemical descriptors and the activity was built with the partial least square(PLS)approach.The model is:A=51602εHOMO+6σ+12546,which indicates that the catalytic activity A is positively correlated with the HOMO energyεHOMOand the ligand polarizabilityσ,with the contribution ofσbeing larger,εHOMO smaller.The model’s coefficient of determination r^2=0.96 and that of cross validation q^2=0.94,both being close to 1,which means that its quality is well and its predictive power is strong.Analysis of the modeling process and the resulted QSAR model,together with the interpretation of the model’s mechanism,also shows that the model obtained from this study is valid and reliable.According to the QSAR model,the mechanism of catalyst activity can be interpreted as that neodymium carboxylates with higher HOMO energy and larger ligand polarizability are easier to react with the co-catalysts so as to produce more active and stable centers of catalyst,resulting in a higher activity.

An Interpenetrated Three-dimensional Framework Sodium Lanthanide Carboxylate Based on[Ho_4(μ_3-OH)_4]^(8+) Cluster

A novel sodium holmium carboxylate compound,namely Na 4 Ho 4 （μ 3-OH） 4 （1,4BDC） 6 ·6.25H 2 O （1,1,4-BDC=1,4-benzenedicarboxylate）,has been solvothermally synthesized and structurally characterized.The structure features a two-fold interpenetrated three-dimensional open-framework constructed by the [Ho 4 （μ 3-OH） 4 ] 8＋ clusters bridged by 1,4-BDC ligands.The Na ＋ ions and lattice water molecules are located in the channels.The structure is further stabilized by hydrogen-bonding and π-π stacking interactions.The thermal stability of the compound has been investigated via thermogravimetric analysis.

Purifying chylous plasma by precluding triglyceride via carboxylated polyethersulfone microfiltration membrane

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations.The current centrifugation procedure is high-cost and time-consuming.Herein,we fabricated an anionic microfiltration polyethersulfone(PES)membrane modified by interface swelling and implanting of acrylic acid(AA)for screening out large particle lipoprotein chylomicron(CM)and adsorbing cationic very low-density lipoproteins(VLDL).To improve the separation efficiency,a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22μm respectively were conducted.Attenuated total reflection Fourier transform infrared technique(ATR-FTIR),water contact angle(WCA),Zeta potential and scanning electron microscope(SEM)were employed to characterize the modified membrane.To test the effectiveness of this membrane,plasma flux and concentration variation of plasma components were examined to study the purification effectiveness.Furthermore,the hemocompatibility of modified membranes was tested to confirm its practicability on bloodcontacting materials.The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

Synthesis, Crystal Structure, and Magnetic Properties of a Co Metal-organic Framework with Mixed Dicarboxylate and Tricarboxylate Ligands

One new mixed-ligand coordination polymer,namely[Co2（btc）（bpdc）（0.5）（py）3]n（1）,was hydrothermally synthesized using biphenyl-2,4,4＇-tricarboxylic acid（H3btc） as a main building block,along with two auxiliary ligands（H2bpdc = 2,2＇-bipyridine-5,5＇-dicarboxylic acid and py =pyridine）.The product 1 was characterized by IR spectroscopy,elemental,thermogravimetric,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction studies show that compound 1 possesses an intricate 3D metal-organic framework based on tetracobalt（Ⅱ） units.Magnetic susceptibility measurement indicates that compound 1 shows an antiferromagnetic coupling between the Co（Ⅱ） ions.

Synthesis and Structural Characterization of new Tri(2-methyl-2-phenylpropyl)tin Carboxylates containing Germanium

Eight tri(2-methyl-2-phznylpropyl) germylpropionates have been synthesized. and their structures were characterized by elemental analysis, IR, multinuclear NMR(H-1,C-13.Sn-119) and MS. The spectroscopic studies revealed that compounds of this type possess a tetrahedral geometry, which have been expected to have good biological activity.

Nano-sized carboxylates as anode materials for rechargeable lithium-ion batteries

Nano-sized caiboxylales Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries.Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs.Li＋/Li.potentially improving the safety of the batteries.In addition,good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.

Triphenylphosphine Stabilized Silver Carboxylates

A series of novel triphenylphosphine stabilized silver carboxylates, potential precursors for CVD growth of ultrafast interconnection link in microelectronic devices, have been prepared and characterized.

Syntheses and Photosensitive Effects of Rare Earth Carboxylate Complexes

Six kinds of cerium carboxylate (CeCar(3)) and rare earth carboxylate (RECar(3), RE=La+Ce+Pr) complexes were synthesized, and the compositions and characters of these complexes were studied by elementary analysis, thermo-gravimetric and differential thermal analysis (TG-DTA), infrared (IR) spectroscopy and ultra violet (UV) spectroscopy. The carbonyl indexes (CI) of law density polyethylene (LDPE) films containing CeCar(3) or RECar(3) during UV photooxidation were determined by IR spectroscopy. The effects of CeCar(3) or RECar(3) on the UV photooxidation rates, viscosity and average molecular weights (M(n)) of LDPE films were studied by using CI, and their mechanisms in sensitizing photooxidation degradation of LDPE films are discussed. Results show that the lifetime of LDPE films can be controlled by adding 0.1 wt%similar to 0.3 wt% CeCar(3) complexes to LDPE films.

A New Series of Charge-assisted Hydrogen-bonded Host Frameworks Based on [Co(en)_3]^(3+)and Dicarboxylates

A new series of metal complex carboxylates（MCC）made of [Co（en）3]3＋（MC）and either 2,6-naphthalenedicarboxylic（NDC）or 4,4-biphenyldicarboxylic（BPDC）were synthesized and structurally characterized.The four new compounds have a general formula（MC）2（C）3·n（guest）with the guests of dimethylformamide（DMF）and dimethyl sulfoxide（DMSO）and water.All the structures represent a pillared-layer type,where the layer consists of MC cations,carboxylate anions or water molecules via a large number of hydrogen bonds.The layers are pillared by the organic residues of NDC or BPDC,resulting in the inclusion cavities where the guest molecules reside.Although their topological structures are similar,they crystallize in different crystal structures due to the rearrangement of pillars and hydrogen-bonded layers.

Synthesis of Novel Nucleoside: 2'-deoxyuridine-3',5'-di(4, 4'-dimethoxy-5, 6, 5', 6'-dimethylenedioxybipheny1-2-methoxy carbonyl 2'-carboxylate)

Hepatitis B Virus (HBV) belongs to the family of hepadnaviridac which comprisesseveral animal viruses, including human HBV. woodchuck hepatitis (WHV). ground squirrelhepatitis virus (GSHV) and duck hepatitis B virus (DHBV), These viruses share commonfeatures such as the genome organization, mode of replication and similar tropism tar hepatocytes'.2'-deoxyuridine-substituted biphenyl carboxylate was synthesized as anti-hepatitis B agents. Thestructure was confirmed by UV. IHNMR spectrum and elementary analysis.

Two-dimensional Grid-type Zinc(Ⅱ) Coordination Polymer Constructed by a New Aromatic Carboxylate Ligand

A new aromatic carboxylate ligand,namely 5-（pyrrolidin-1-yl）-1,3-benzenedicar-boxylic acid（H2pybdc）,was synthesized and characterized by FT-IR and single-crystal X-ray diffraction analysis.It crystallizes in triclinic system,P1 space group with a = 10.05（5） ,b = 11.53（5）,c = 12.92（6） ,α = 112.11（6）°,β = 92.79（7）°,γ = 102.98（7）°,V = 1337.113,Z = 4,Mr = 253.25,Dc = 1.258 g.cm-3,μ = 0.099 mm-1,F（000） = 536,the final R = 0.0822 and wR = 0.2575 for 1893 observed reflections（I 2σ（I））.Based on it,a two-dimensional grid-type Zn（Ⅱ） coordina-tion polymer of {[Zn（pybdc）（bpy）（H2O）].2H2O.0.5CH3OH}n（1） was solvothermally synthesized,which crystallizes in triclinic,space group P1 with a = 10.218（5） ？,b = 11.176（5） ,c =11.350（5） ,α = 95.855（5）°,β = 94.248（5）°,γ = 101.421（5）°,V = 1257.9（2） 3,Z = 2,Mr = 524.84,Dc = 1.386 g.cm-3,μ = 1.024 mm-1,F（000） = 546,the final R = 0.0635 and wR = 0.1879 for 3913 observed reflections（I 2σ（I））.

Synthesis, Structure, and Magnetic and Luminescent Properties of Rare Earth Coordination Polymers Constructed from Mixed Dicarboxylates

Three unique metal-organic framework coordination polymers, [Eu_2(bptc)(bdc)_2(H_2O)]_n(1), [Gd_2(bptc)(bdc)_2(H_2O)_4]_n(2) and [Dy_2(bptc)(bdc)_2(H_2O)_4]n(3)(1,2-H_2 BDC = 1,2-benzenedicarboylic acid, H_2 bptc = 4,4?-biphenyldicarboxylic acid) were synthesized by mixing two different multi-carboxylic acids with Ln2 O3(Ln = Eu, Gd and Dy) in hydrothermal condition. The three compounds are all three-dimensional and compounds 2 and 3 contain 4.289 × 6.507 ?~2 rectangularshaped one-dimensional open channels along the a direction. Additionally, the magnetic, luminescent and thermogravimetric properties were studied in detail.