Study on EPR Spectra of Three Gadolinium Complexes With Noncyclic Polyether Schiff Bases

The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ' of complexes were estimated. A series of interesting regularity and new results were obtained.     

α-Oxo Ketene Dithioacetals Chemistry-A Facile Route to the Synthesis of Fused Heterocyclic Compounds

Q-Oxo ketene dithioacetals and related compounds are versatile synthons in organicsynthesis'-'. The substitution reaction of or-oxo ketene dimethylthio acetals with diamineis one of the impel'tant applications for the synthesis of corresponding a-oxo ketenecyclic N, N-acetals. Junjappa and co-workers described this reaction ill a review'.However, since some kinds of ketene dimethylthio acetals are not easy to prepare, themethod melltioned above is limited. Zhu and co-workers had successfully…     

Evaluation of Two-center One- and Two-electron Integrals over Slater Type Orbitals

A formulation previously presented by the authors for coulomb integrals was generalized to other two-center integrals, except exchange integral. Within this frame, molecular integrals were expressed in terms of some new functions closely related to the well-known incomplete gamma functions and these functions recursively evaluated. Special issues arising in the case of hybrid integrals were addressed, and the results were compared with the ones found in the literature.     

Electrochemical Studies of Eight New Divalent Transition Metal Benzenesulphonate Ternary Complexes with 1,10-Phenanthroline

The electrochemical properties of eight new divalent transition metal benzenesulphonate complexes with 1, 10-phenanthroline in different solvents and supporting electrolytes were investigated by means of cyclic voltammetry(CV). Based on the CV data the influences of various coordination modes on the electrochemical behavior of the complexes were discussed. The diffusion coefficient Dc and rate constant k, of those complexes in DMF systems were estimated according to CV and the results show that these processes were all quasi-reversible.     

SUBSTITUTION REACTIONS OF ALKANES (Ⅴ)——PHOTONITROSATION OF SOME ALKANES

A rather satisfactory method of synthesis of aldoximes and ketoximes by direct nitrosation of alkanes and an adequate technique of separating the mixtures and identifying the components from the reactions were worked out.By these procedures, the nitrosation of pentane, hexane and heptane gave different results from those reported in literature, and the study on octane was new.     

α-OXOKETENE CYCLIC DITHIOACETAL CHEMISTRY(XⅢ)-THE ETHERIFYING REACTION ON THE ADDUCTS OF ALIPHATIC α-OXO KETENE CYCLIC DITHIOACETALS WITH ALLYL MAGNESIUM BROMIDE

Aliphatic α-oxo ketene cyclic dithioacetals 1 were reacted with allyl magne-sium bromide to afford the 1,2-addition products 2.Catalyzed by boron trifluorideetherate,the adducts 2 were etherified by methanol to afford the corresponding methylethers 3.This process provides a new method for the protection of the acid sensitivehydroxyl group in 2 under mild condition.     

DISCRIMINATION OF Moraxella AND Legionella pneumophila BY GAS CHROMATOGRAPHY OF WHOLE-CELL FATTY ACIDS

Whole-cell fatty acid profiles of 36 strains of Moraxella and its related bacteria, and 13 strainsof Legionella pneumophila were obtained by capillary gas chromatography (GC). Some component peaksin these profiles were analyzed by gas chromatography-mass spectrometry (GC-MS). Hierarchical clus-tering analysis of these bacterial fatty acid patterns was done with a microcomputer. Results showedthat these were some obvious differences between the two new species of Moraxella isolated in China,i.e. M. amylolytica and M. nanchang, and the currently established reference strains of this genus. Themajor fatty acids of these two new species were the isomers of pentadecanoic (C_(15:0)) acids. Theprofiles of L. pneumophila NJ 8331 and LDB 4_a recently isolated in China were essentially similar tothose of international reference strains type 1-8 (CDC, USA), which contained mainly 16-carbon (C_(16))acids, whereas another isolate LDB 4b was obviously dissimilar. The results of this method of discrim-ination and of t     

Polydentate cyclotriphosphazene ligands:Design,synthesis and bioactivity

Five multinuclear cyclotriphosphazene ligands were synthesized and tested for their cleavage activities to plasmid DNA.All of these new compounds were confirmed by MS,~1H NMR,~(31)p NMR,~(13)C NMR and IR.Preliminary studies on the cleavage of pUC 19 DNA in the presence of metal complexes were performed.The results revealed that these complexes could act as powerful catalysts under physiological conditions.The complexes 3b+Cu can effectively cleave DNA to nicked form,giving hydrolysis rate constant of 0.0...     

Using Nuclear Magnetic Resonance and MS/MS Spectroscopy for the Identification of Brodimoprim Metabolites in Rat Urine

Brodimoprim,a trimethoprim analogue diaminopyrimidine, 2,4-diamino-5-(4'-bromo-3',5'-dimethoxybenzyl) pyrimidine, is a new inhibitor of bacterial dihydro folate reductases (OHFRs), it shows activity against a broad spectrum of Gram-positive and negative-bacteria. Recently we reported the results of the study on the metabolites of brodimoprim in vivo with SPE-NMR method (solid phase extraction coupled with nuclear magnetic resonance), five metabolites were detected in rat urine1. They were …     

Synthesis and anticancer activities of porphyrin induced anticancer drugs

In view of the property of porphyrin's accumulation selectively in tumor,the ftorafur was modified by binding a porphyrin block to improve its tumor targeting and reduce its side effects.These novel porphyrin derivatives and metal compounds were synthesized under mild conditions with satisfactory yield,and the constructions of all these new compounds were characterized by UV,IR,MS, ~1H NMR spectra and elementary analysis.Their anticancer activities were evaluated by MTT assay;the results indicated that the anticancer activities of compounds 4a-c were twice as high as that of ftorafur.     

Fimbrialtols K–M,highly functionalized ent-kaurane diterpenoids from traditional Chinese plant Flickingeria fimbriata(B1.) Hawkes

Three new ent-kaurane diterpenoids fimbrialtols K–M(3–5) with highly substituted functionalities were isolated from the extract of Flickingeria fimbriata(B1.) Hawkes. The structures of these new compounds were determined by NMR and HR-ESIMS. The relative configurations of these compounds were determined by analysis of NOESY correlations. The absolute configurations of these new compounds were established by CD methods together with considering the biosynthetic pathway. Compounds 3 and4 contain a cinnamic carboxyl group, whereas compound 5 possesses a benzoic carboxyl group representing the first report in more than known 600 ent-kaurane diterpenoids.     

Asymmetric Diels—Alder Reaction Catalyzed by Novel Chiral Dibenzo[a,c] cycloheptadiene Bis（oxazoline） Metal Complexes

A series of novel chiral C2-symmetric bis (oxazoline) ligands have been synthesized.The copper and magnesium complexes,prepared in situ from copper(Ⅱ)-triflate of magnesium triflate with the new enantiopure oxazoline ligands,were evaluated as chiral catalysts in the enantioselective Diels-Alder reaction of cyclopentadiene with N-crotenoyl-oxazolidin-2-one.Primary results showed that diastereoselectivity up to 94% and enantioselectivity up to 68% ee for endo products were observed respectively with these ligands.     

Sulfated binary and trinary oxide solid superacids

A series of sulfated binary and trinary oxide solid superacids were prepared, and their catalytic activities for n-butane isomerization at low temperature were measured. The incorporation of different metal oxides into ZrO2 may produce a positive or negative effect on the acid strength and catalytic activity of the solid superacids. Sulfated oxides of Cr-Zr, Fe-Cr-Zr and Fe-V-Zr are 2 - 3 times more active than the reported sulfated Fe-Mn-Zr oxide. The enhancement in the superacidity and catalytic activity of these new solid superacids has been discussed on account of the results of various characteriation techniques.     

Pyromeconic acid derivatives from Conyza canadnsis(L.) Cronq

A new pyromeconic acid derivative,pyromeconic acid-3-O-β-D-glucopyranoside-3′-(O-β-D-glucopyranoside)-6′-(O-4″-hydroxybenzoate) (1),along with two known ones,were isolated from the whole plants of Conyza canadensis.Their structures were elucidated based on the analysis of their spectroscopic data.The in vitro antibacterial testing results showed that all of these three compounds were inactive towards two bacterial strains,Escherichia coli and Staphyloccocus aureus.     

Novel Roles of Metal Ions in Layered Self-assembled Films of Polynuclear Complexes on Their Photoinduced Electron Transfer Properties

Three metal ion bridged self-assembled(SA)films of cis-di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium were fabricated and characterized by contact angle,UV spectra,cyclic voltammetry and XPS.Theirphotoinduced electron transfer properties(PETP)were examined.Among the titled systems,the highest steady an-odic photocurrent of 1773—1843 nA/cm~1 and the highest quantum yield of 3.2% were achieved.The effects of in-cident light intensity,bias voltage,and electron donor were also studied.The possible mechanism of electron trans-fer was proposed.The results reveal that different metal ion in SA films could affect significantly the photoinducedelectron transfer property.Our experimental results clearly show that bridging metal ions can play both functionaland structural roles in these self-assembled systems.This method of forming functional films can provide a new ap-proach to regulate the property of similar systems.     

Synthesis and Biological Activity of Novel 2,3-Dihydro-2-phenylsulfonylhydrazono-3-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosyl)thiazoles

A series of novel 2,3-dihydro-2-phenylsulfonylhydrazono-3-(2',3',4',6'-tetra-O-acetyl-β-D-glucopyranosyl) thiazoles were designed and synthesized via the reaction of thiosemicarbazide with chloroaldehyde.Their chemical structures were characterized by 1H and 13C NMR spectroscopy and elemental analysis.The bioassay results indicate that some of these compounds exhibit moderate fungicidal and herbicidal activities.     

Synthesis and Herbicidal Activity of Novel 5-Substituted Benzenesulfonylureas

Sulfonylurea herbicides have been widely used because of their low application rates,good crop selectivities and low mammalian toxicities.However,some sulfonylureas might persist unfavourably in the environment with residual problems.In order to look for ecologically safer and environmentally benign sulfonylureas,and on keeping the pyrimidine ring being monosubstituted,15 novel C5-monosubstituted benzenesulfonylurea compounds were synthesized.The structures of all the compounds synthesized were confirmed by elemental analysis and 1H NMR.Preliminary herbicidal activities of these new sulfonylurea compounds were determined by ALS screening(in vitro)and pot bioassay experiments(in vivo).The herbicidal results show that some novel sulfonylureas are comparable to commercial Foramsulfuron and Monosulfuron.     

STUDIES ON ORGANO-MOLYBDENUM AND TUNGSTEN COMPOUNDS(Ⅲ)——CATALYTIC POLYMERIZATION OF ACETYLENE BY M-O-C BOND-CONTAINING COMPLEXES OF Mo AND W

Catalytic polymerization of acetylene in the presence of n5-C5H5-M-(CO)3 R (M=Mo,W;R=CH3-,C2H5-) has been studied.The results show that these complexes possess catalytic activities for the polymerization and copolymerization of monosubstituted acetylene.The catalytic mechanism has been preliminarily discussed.It is suggested that the active species be metal-car-bene.In our previous publications we reported the synthesis of some new Fischer's molybdenum and tungsten-carbene complexes and catalytic activity for alkyne polymerization.The results show that the activity of Fischer's molybdenum-carbene is higher than that of tungsten.The catalytic polymerization of alkyne by M-σ-c bond-containing complexes of molybdenum and tungsten has not been reported yet in literature.Therefore,four M-σ-C bondontaining complexes of molybdenum and tungsten were synthesized by using the method reported in the literature,and catalyst polymerization of alkyne by these complexes was examined.     

Discriminating against injectable fat emulsions with similar formulation based on water quenching fluorescent probe

The discrimination against nutritional fat emulsion injections was considered by imaging tools,which aims to elucidate the in vivo behaviors of nanoemulsions.In this study,20%nutritional fat emulsion injections were selected from different company including original and generic products.Meanwhile,a water quenching fluorescent probe(P2)was used to label them by an incubation method.The fluorescent intensity analysis of blood-borne fluorescence reveals rapid clearance of nanoemulsion in all groups,which shows'L'-type blood kinetic profiles.However,these kinetic parameters do not have significant difference.Following intravenous administration,the nanoemulsions in all groups concomitantly accumulated in organs of reticulo-endothelial system(RES),such as liver and spleen,and were cleared from body circulation mostly after 12 h.AUC(0-t)of organs from different groups showed dissimilar results in some organs.These intuitional results are of significance in understa nding the in vivo behaviors of nanoemulsions,which can provide a new way to discriminate against nutritional fat emulsions.     

Subsolidus Phase Relations in the TiO_2-NiO-WO_3 System

The subsolidus phase relationships of the system TiO2-NiO-WO3 were investigated, aiming at exploring new potential visible-light active photocatalysis systems. After the solid-state chemistry reaction in air between 1000 and 1150 ℃, X-ray diffraction(XRD) data showed that two binary compounds and three ternary-phase regions were contained in this ternary system. No new ternary compound was discovered under our experiment conditions. None of these phases in this system revealed a remarkable homogeneity range.