Crystal Structure and Herbicidal Activity of 5,7-Dimethoxy-(2,4-dichlorophenoxyacetyl- imino)-2H-1,2,4-thiadiazolo[2,3-a]pyrimidine

1 INTRODUCTION 2H-1,2,4-Thiadiazolo[2,3-a]pyrimidine compounds are a new series of ALS inhibiting agents besides sulfonylurea herbicide. Their herbicidal activity is similar to that of sulfonylurea herbicide, but be- cause of weak S–N bond existing in 2H-1,2,4-thiadi- azolo[2,3-a]pyrimidine ring, which is advantageous for the absorption and metabolism of vegetable, 2H- 1,2,4-thiadiazolo[2,3-a]pyrimidine herbicides have better selectivity[1～3]. At present, reports about the synthesis…     

Reaction of 2,3-Dihydro-1,5-benzothiazepines and Phenylacetyl Chloride in the Presence of Triethylamine： A New Aspect on the Formation Mechanism of Dihydro-1,3-oxazin-4-one Derivatives

2a,4-Disubstituted 2,2a,3,4-tetrahydro-2-phenyl-1H-azeto[2,1-d][ 1,5]benzothiazepin-1-ones, as well as 2-substi-tuted 2,3-dihydro-3-phenylacetyl-2-styryl-benzothiazoles and 4a,6-disubstituted 3- .benzyl-4a,5-d/hydro-2-phenyl-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, were obtained from the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines with phenylacetyl chloride in the presence of triethylamine. The mechanism for the formation of 4a,5-dihydro-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, 2,3-dihydro-1,3-oxazin-4-one derivatives, was suggested.     

A STUDY ON THE STRUCTURAL EFFECT OF DOUBLE-BRIDGED CONJUGATIVE SYSTEMS

In this paper, the following carbonyl-imino bridged compounds and related analogs havebeen synthesized:X= C1, m = 0); and the structural effect of the carbonyl-imino bridges has been studied by means of the UV and other properties of the compounds. A new conception of conjugative segment is put forward. The structural bases for each of the three π-π* bands of (C) are ascertained and verified by modification on structure of segments, such as eliminating, merging, lengthening or shortening of segments. It is demonstrated that both bridges -CO-and -NH- can block the conjugated polarization of the whole molecule so as to form three segments S, M and L of which the λmax each exhibits relative independence. The electronic absorption peaks resulting from different segments can be readily recognized and the existence of each segment can be ascertained. This may provide a new way for structural analysis of bridged compounds.     

QSAR Study and VolSurf Characterization of Human Intestinal Absorption of Druge

The prediction of human intestinal absorption is a major goal in the design,optimization,and selection of candidates for the develoment of oral drugs.In this study,a computerized method(VolSurf with GRID) was used as a novel tool for predicting human intestinal absorption of test compound,and for determining the critical molecular properties needed for human intestinal absorption.The tested molecules consisted of 20 diverse drug-like compounds.Partial least squares(PLS) discriminant analysis was used to correlate the experimental data with the theoretical molecular properties of human intestinal absorption.A good correlation(r^2=0.95,q^2=0.86) between the molecular modeling results and the experimental data demonstrated that human intestinal absorption could be predicted from the three-dimensional(3D) molecular structure of a compound .Favorable structureal properties identified for the potent intestinal absorption of drugs included strong imbalance between the center of mass of a molecule and the barycentre of its hydrophilic and hydrophobic regions and a definitive hydrophobic region as well as less hydrogen bonding donors and acceptors in the molecule.     

STUDY ON THE CHAIN-EXTENDING REACTION OF POLY (ETHYLENE TEREPHTHALATE) WITH 2, 2′-BIS (4H-3, 1-BENZOXAZIN-4-ONE)

2,2'-Bis (4H-3, 1-benzoxazin-4-one) (BBON) has been proved to be an effective chainextender for poly (ethylene terephthalate) (PET). In order to study the reaction mechanismand kinetics of chain-extending reaction, β-bishydroxyethylene terephthalate (BHET) wasselected as model compound. The NMR data, IR spectra and number average molecularweight (M_n) of the products obtained from the reaction of BBON and BHET verify thatBBON is a hydroxyl-reactive extender. The mechanism was discussed. Kinetics dataindicate that extending reaction is a second order reaction, and BBON has high reactivity.The activation energy (E_a) was measured.     

POLYMERIC PHOTOSTABILIZERS CONTAINING TWO KINDS OF PHOTOSTABILIZING GROUPS Ⅱ. SYNTHESIS AND PHOTOSTABILITY OF COPOLYMERS OF 2,2,6,6-TETRAMETHYL-4-PIPERIDINYL METHACRYLATE AND β-HYDROXY-γ-(ORTHO-HYDROXY BENZOXY) PROPYL METHACRYLATE

A new kind of photostabilizers, eopolymer of 2, 2, 6, 6-tetramethyl-4-piperidinyl methacrylate and β-hydroxy-γ-(ortho-hydroxy benzoxy) propyl methacrylate, has been synthesized. The spectral behaviors of these copolymers were studied in detail. In the presence of salicylyl group a strong absorption in the region of 280—330 nm could be observed, and an unusual Stoke's shift appeared in the fluorescence spectrum excited by 310nm. The photostabilization ability of these copolymers in the process of photodegradation of cis-poly (butadiene) was studied. Results indicated that these compounds possess excellent photostabilization ability.     

Action mechanism of antioxidation and anticorrosion and molecular design for perfluoropolyether fluid additives (Ⅱ)——Synthesis and measurement of N-substituted perfluoropolyalkylether phenyla-mide

Three kinds of the antioxidation and anticorrosion additives from the N-substituted per-fluoropolyalkylether phenylamide (PFPEA) were selected and synthesized. UV and IR spectral analyses were carried out, and strong absorption peaks of UV from benzene ring are about 240.7, 215.4 and 230.1 nm, respectively. The characteristic peaks of IR from the C=O are about 1713.9, 1712.2 and 1710.8 cm-1, respectively. The antioxidant and anticorrosive property was tested for the three synthesized additives. The results show that the weight loss of lubrication oil can decrease by 1/7, 1/9 and 1/25 respectively after adding synthesized additives. The thermal decomposition temperature(TD) in the presence of AI2O3 can increase by 19-22℃. From theoretic and experimental study it indicates that the PFPEAs with nitrogen heteroatom not only accepts electron from perfluoropolyalkylether oxygen radical (RfO.) to form a stable adduct and to prevent RfO. decomposing further, but also donates electron to form chemical adsorption fil     

TARNISH AND PROTECTION OF SILVER DEPOSIT——MECHANISM AND METHOD

The mechanism of tarnish caused by exposure to light and Na_2S solution treatment on silver-electroplated deposit and the antitarnish effects of various antitarnish agents have been investigated in this paper. The results showed that 1-phenyl-5-mercaptotetrazole (PMTA) has excellent antitarnish effect for UV light and H_2S tests.The studies of XPS and AES and UV absorption spectra showed that PMTA can absorb effectively UV light and form a dense surface film which can prevent effectively the reactions between silver deposit with corrosive media.Antitarnish surface film could be composed of a polynuclear coordination polymeric compound with structure unit approximate to [Ag_3(PMTA)]. according to the depth dependence of percent component (C%) and sputtering time.     

Studies on Synthesis and Biological Activities of Novel Triazole Compounds Containing Pyrimidine or N, N－Dialkyldithiocarbamate Ring

Twelve of the title compounds were synthesized. Their structures were identified by means of IR, EA, IH NMR and MS. The IR spectra clearly show that the absorptions in the regions of 1716—1666 cm^-1 and 1505—1499 cm^-1 are the characteristic absorption bands for vc=O and vc=N. In the IH NMR spectra of target compounds(10a—10g), three protons of a = CH—CH2— group present three sets of quartet peaks of the protons. The preliminary bioassays showed that the synthesized compounds exhibited some activities of fungicides and plant growth regulators.     

NEW HETEROCYCLIC SYSTEM SYNTHESIS H THE REACTION OF 2,3-DIHYDRO-1,5-BENZOTHIAZEPINES WITH DICHLOROCARBENE

The reaction of two series of 2,3-dihydro-1,5-henzothiazepines Ⅰ with dichloro-carbene,gave azirino[2,1-d][1,5]benzothiazepines Ⅷ,azirino[2,1-e][1,6]benzothiazocines Ⅸ,pyrrolo[2,1-b][1,3]benzothiazoles Ⅹ,substituted-cyclopropanes Ⅺ and 2H-1,4-benzothiazin-2-onesⅫ.The structures of these products were confirmed by the analytical and spectral data.CompoundⅧ and Ⅸ are two new ring systems.     

Growth and Characterization of Crystal Nd_(0.06)Y_(0.94)Sr_6Sc(BO_3)_6

<正>The crystal of Nd0.06Y0.94Sr6Sc(BO3)6 with the dimensions up to 35 mm × 28 mm × 13 mm was grown by a top-seeded solution growth method from Li6B4O9 flux. The grown crystal was characterized by X-ray powder diffraction. The optical absorption of the crystal shows that it has a strong absorption band at 8070 A, and the absorption coefficient is 2.17cm-1 with a FWHM of 41 A, which can match with the wavelength of the diode-laser (LD) and is suitable for the LD pumping. Based on the Judd-Ofelt theory, the three parameters of line oscillator strength Ω(λ) (λ = 2, 4 and 6) of the Nd3+ion in the crystal were calculated as follows: Ω2= 1.194 × 10-20, Ω4= 4.186 × 10-20 and Ω6 = 3.351 × 10-20cm2, which are relatively larger. The results indicate that the crystal Nd0.06Y0.94Sr6Sc(BO3)6 may be a kind of high-efficient laser material for diode-pumped.     

Syntheses,Crystal Structures and DNA-binding Properties of Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) Compounds Containing Thiazole Derivatives

Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1～3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) have been determined by single-crystal X-ray diffraction analysis, which shows that all the three complexes belong to monoclinic system with space group P21/c. Time-dependent density functional theory(TD-DFT) calculation is performed on a reference structure of compound 3. The excited electrons mainly localized at the π* of ligand 2-(2-pyridyl)benzothiazole, which will be convenient for them to bind with the DNA reacting sites. Fluorescence spectroscopy, ultraviolet(UV) spectroscopy and viscosity were used to characterize the interaction of the compounds with Calf thymus DNA(CT-DNA). The results indicate that compounds 1～3 bind to CT-DNA and have a strong interaction with DNA. The compounds can probably bind to CT-DNA via a non-intercalative mode as concluded by studying the viscosity of a DNA solution in the presence of the compounds. This combination can effectively break DNA, which speculates that these three compounds may interact with the cancer cell DNA in this binding mode, thereby damaging the cancer cells.     

STRUCTURAL EFFECT IN FORKED CONJUGATIVE SYSTEMS——BIFURCATION-TYPE OF FORKED POLYENIC NITRILES,CARBOXYLIC ACIDS AND ESTERS

Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano andcarboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon theintroduction of an electron-attractive branching group, just like the case of introducing anelectron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the corres     

THE SYNTHESIS AND CHARACTERIZATION OF THE COORDINATION COMPOUNDS OF Pt(Ⅱ)AND Ir(Ⅲ)WITH 2-MERCAPTOPYRIDINE-1-OXIDE AND ITS METHYL DERIVATIVES

Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT~-,3Me-PT~-or 4Me-PT~-)are reported here.Four coordination compounds of the lattertwo ligands have never been reported before,while PT~-'s were synthesized withH_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods ofDavidson et al.~1 and Sterinbrech~2.They were characterized by elemental analysis,UV,IR,~1HNMR and molar conductance.Their structural formulas have beendetermined,and the mechanism of synthetic reaction has been discussed.     

THE IONIZATION OF EXCIPLEXES FORMED BY CYANO-CONTAINING OLEFINIC COMPOUNDS AND N,N-DIMETHYL-p-TOLUIDINE

The absorption spectra, fluorescence spectra and photoconduction of some systems com-posed of different cyano-containing olefinic compounds and N, N-dimethyl-p-toluidine (DMT)have been studied in this paper. The experimental results show that the exciplex emissionspectra can be observed when the systems of acrylonitrile (AN) or methacrylonitrile (MAN)with DMT are illuminated, whereas the exciplexes between trans-1, 2,-dicyanocthylene(DCNE) or tetracyanoethylene (TONE) with DMT could not be found from the spectra dueto their large ionization. The measurements of photoconduction provide further a clear andunambiguous evidence for the ionization of the systems mentioned above, and they are thesupplement to the systems studied here.     

Calix[4] crowns with Methoxynaphthoylmethyl Pendant Groups

The novel calix [4] crowns with two pendant groups were prepared by the alkylation of calix 141 crowns with 6-methoxy-2-bromoacetylnaphthalene. ^1H NMR titration and picrate extraction experiments indicated that they exhibit higher complexing efficiency than their parent compounds and possess obvious selectivity for Na^ or K^ , respetively, and that the cation is encapsulated inside the preorganized ionophoric cavity defined by carbonyl oxygens, the crown ether and the phenoxy oxygens.From UV and fluorescent spectra it is revealed that calix [4]crown-4 3a with 6-methoxy-2-naphthoylmethyl pedant groups exhibits remarkable cation-induced photophysical effects and it could be utilized as a selective fluorescent sensor for Ca^2 .     

THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p-nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate.     

THE COMPATIBILITY OF BLENDS OF POLY(VINYL CHLORIDE) OR CHLORINATED POLY(VINYL CHLORIDE) WITH POLY(METHYL METHACRYLATE)

IR spectral shifts of carbonyl vibrational absorption for ethyl acetate, which acts analogically as the structural unit of poly(methyl methacrylate), in cyclohexane, chloroform, chlorinated paraffins, poly(vinyl chloride) and chlorinated poly(vinyl chloride) were measured. The results suggest that there are specific interactions between the carbonyl groups and the chlorinated hydrocarbons which could be responsible for the apparent compatibility of poly(vinyl chloride)—poly(methyl methacrylate) and chlorinated poly(vinyl chloride)—poly(methyl methacrylate) blends. Additionally, the effects of the preparation mode of blend films on phase separation and observed compatibility are discussed.     

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 structure of linear hexanuclear manganese (Ⅱ)benzoate cluster

From a reaction system including benzoic acid and Mn(NO3)2 in alkali medium, two hexanuclear manganese benzoate cluster compounds have been synthesized. A compound [Et4N]2[Mn6(PhCOO)14] has been structurally characterized, which contains hexanuclear Mn11 moieties extending unlimitedly to form one-dimensional linear structure. Carboxyl oxygen atoms are bridged in variety of modes to the Mn atoms, forming an arrangement like a sinusoid for the Mn atoms. The structural parameters of these compounds were compared with the data obtained from EXAFS determination for the Mn cluster in the OEC of PS11, supporting that the coordination sphere of the Mn site in the OEC may contain carboxyl bridges. The possible combination modes between the carboxyl group and the Mn atoms have been suggested. The NMR signals exhibit widening and shift produced by the influence of the paramagnetic Mn" sites. The red-shift of the absorption in IR spectrum was observed to be attributed to the coordination of the carboxyl group to the Mn