（E）-1-[4-（2-hydroxy-5-methoxybenzylideneamino）-phenyl]ethanone and （E）-1-[4-（2-hydroxy-4-methoxybenzylideneamino） phenyl]ethanone：X-ray and DFT-calculated structures

The isomeric structures of(E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)-phenyl] ethanone(I) and(E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino) phenyl]ethanone(Ⅱ) ,both C16H15NO3,have been determined using X-ray diffraction techniques and characterized by IR,and their molecular structures have also been optimized at the B3LYP/6-31G(d,p) level using density functional theory(DFT) . The energetic behaviors of the title compounds in solvent media have been examined using B3LYP method with the 6-31G(d,p) basis set by applying the polarizable continuum model(PCM) . The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition,DFT calculations of the title compounds' molecular electrostatic potentials(MEP) were performed at the B3LYP/6-31G(d,p) level of theory. X-ray study shows that the title compounds both have strong intramolecular O-H…N hydrogen bonds. The molecules of Ⅰ are linked into a one-dimensional framework structure by C-H…π interactions,while in Ⅱ,intermolecular π···π interactions result in the formation of infinite chains running along the [010].     

Crystal Structure and DFT Studies of a Triazole Derivative： 4- （ 2-Hydrobenzylideneamino ） -3- （ 1,2,4-triazol-4-ylmethyl） 1H-1, 2,4-triazole-5 （4H） -thione

A novel triazole derivative 4-(2-hydrobenzylideneamino)-3-(1,2,4-triazol-4-ylmethyl)-1H-1,2,4-triazole-5(4H)-thione(1) was synthesized and characterized using elemental analysis, FTIR, and 1H NMR, and its crystal structure was determined via X-ray single crystal diffraction analysis. Crystal data: monoclinic, P2(1)/c, a=0.83335(9) nm, b=1.49777(16) nm, c=1.14724(12) nm, β =107.990(2)°, D=1.470 Mg/m3, and Z=4. The geometries and the vibrational frequencies were determined using the density functional theory(DFT) method at the B3LYP/ 6-31G level. To demonstrate the accuracy of the reaction route of compound 1, one of the important intermediates was also tested using the same method. The structural parameters of the two compounds calculated using the DFT study are close to those of the crystals, and the harmonic vibrations of the two compounds computed via the DFT method are in good agreement with those in the observed IR spectral data. The thermodynamic properties of the title compound were calculated, and the compound shows a good structural stability at normal temperature. The test results of biological activities show that it has a certain bactericidal ability.     

Molecular Model Design and Quantum Chemistry Calculation of Cluster B4N4

The B4N4 configurations were designed by using the molecular figure software. The full geometry optimization and harmonic vibration frequency analysis were performed at the 6-31G(d) level using density functional theory B3LYP method,which indicates that the five isomers are stationary points on the potential energy surface of B4N4 molecules. The geometry structure,frontier molecular orbital (FMO) and mulliken population have been analyzed. The bonding properties and hybrid type were also discussed in detail,showing the addition of hydrogen atoms to boron or nitrogen atom would increase the stabilities of the BN clusters.     

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine

The hydrolysis mechanisms of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYP/6-31 G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C—N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYP/6-31 G(d, p) level of theory based on the po-larizable continuum model (CPCM). In water the first mechanism (path A) is also favored.     

Synthesis and mesomorphic properties of 4-(4-bromopropyloxy)-4’-(4-alkyloxybenzylidene)anilines

This article describes the preparation and liquid crystalline properties of a new homologous series of 4-（4-bromopropyloxy）-4’- （4-alkyloxybenzylidene）anilines in which the phenyl ring is armed by a bromopropyloxy chain.The thermal behavior and mesomorphic properties of the synthesized compounds were studied with particular attention given to the correlation between their phase transition temperatures and anisotropic change influenced by molecular structure.All the members displayed enantiotropic smectic phase except for the homologue with the longest alkyloxy chain(R = C₁₈H₃₇),exhibiting only monotropic characteristic. The presence of bromine atom from the propyloxy side chain is found to be capable of altering and influencing the mesomorphic properties.     

Synthesis and Bioactivity of Novel Aminomethyl-2-（1, 2,4-triazol）-4, 4-dimethyl-3-pentanone （ol）

3, 3-Dimethyl-1-(1,2,4-triazol)-2-butanone was treated with aqueous formaldehyde to give an additional product, and subsequent elimination by acetic anhydride yielded 4,4-dimethyl-2-(1,2,4-triazol)-1-penten-3-one. Further addition with substituted amines provideda series of (1,2,4-triazol)-4,4-dimethyl-3-pentanone, which were then reduced by KBH4 to obtaina series of (1,2,4-triazol)-4,4-dimethyl-3-pentanol. Their structures were confirmed by ^1HNMR and elemental analysis. The results of bioassay showed that the title products possess good fungicidal activities.     

4-(4-羟基丁基－2－炔氧基)－3-（苯磺酰基）－1，2，5－噁二唑－2－氧化物与牛血清白蛋白结合作用的光谱法研究

The interaction between 4-(4-hydroxybut-2-ynyloxy)-3-(phenylsulfonyl)-1,2,5-oxadiazole-2-oxide(FB)andbovine serum albumin(BSA)was studied by spectroscopic methods including fluorescence and UV-Vis absorptionspectroscopy.The quenching mechanism of fluorescence of BSA by FB was considered to be a dynamic quenchingprocedure.The number of binding sites n and apparent binding constant K were measured by fluorescence quench-ing method.The results indicate that there is FB molecular binding with BSA,and forming 1∶1 complex.Thethermodynamic parameters such as ΔH,ΔG and ΔS,etc.,were calculated.The results indicate that the binding reac-tion is mainly entropy-driven and hydrophobic forces play major role in the binding reaction.The distance r be-tween donor(BSA)and acceptor(FB)was obtained according to Frster theory of non-radioactive energy transfer.     

Synthesis and Crystal Structure of 2-Amino-4- chloro-5-（4-methylbenzyl）-6-methylpyrimidine

The title compound 2-amino-4-chloro-5-(4-methylbenzyl)-6-methylpyrimidine (C26H28Cl2N6, Mr = 495.44) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 14.892(7), b = 6.129(3), c = 14.889(7) , β = 109.795(8)°, V = 1278.7(10) 3, Z = 2, F(000) = 520, Dc = 1.287 g/cm3, μ = 0.280 mm-1, the final R = 0.0577 and wR = 0.1589 for 1357 observed reflections with I > 2σ(I). A total of 6091 reflections were collected, of which 2257 were independent (Rint = 0.033). The X-ray analysis reveals that the chlorine atom and methyl of the title compound are disordered.     

Studies on Fragmentation Regularity of 5-Methoxycarbonyl-4-substit uted-6-methyl-3,4-dihydropyrimidin-2（1H）-ones by Time-of-flight Mass Spectrometry

The electron impact time-of-flight(TOF) mass spectra of the title compounds were studied to establish their fragmentation processes. With the high resolution of the TOF instrument, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the elemental compositions for all the molecular ions and fragments through software interpretation. By further applying the fragmentation regularity, the majority of ions were fully assigned. The main fragmentation pathways of the title compounds include the formation of molecular ions by the loss of R^1 groups in the 4-position and the ester groups in the 5-position. The formed ion can be further fragmented by the elimination of MeOH.     

4- (4,6-二甲基嘧啶-2-基)-3-硫代脲酸甲酯的合成晶体结构及量子化学研究

4-（4,6-Dimethylpyrimidin-2-yl）-3-thio-allophanic acid methyl ester was synthesized with mixing 2-amino-4,6- dimethylpyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray diffraction measurement were obtained by recrystallization from dimethylformamide at room temperature. The crystal belongs to monoclinic symmetry with space group C2/m, and crystal parameters of a= 1.7537（5） nm, b= 0.6759（2） nm, c=1.1148（3） nm, β=118.557（4）°, V=1.1605（6） nm^3, Z=4, De= 1.375 g/cm^3,μ=0.271 mm^-1, F（000）=504, and 1519 [1〉2σ（I）] observable independent reflections were used for the determination and refmement of the crystal structures with final R1 of 0.0372 and wR2 of 0.0992. The theoretical investigation of the title compound was carried out with DRT-B3LYP/6-311G, HF/6-311G and MP2/6-311G methods, and the atomic net charges and the population were discussed.     

Stereoselective Synthesis of （Z）-5-（Trideca-4-enyl）resorcinol and Gibbilimbols A-D

(Z)-5-(Trideca-4-enyl)resorcinol (1) and gibbilimbols A-D(2-5) were synthesized in 47%-60% yields over 6 steps from commercially available starting materials. The Wittig reaction of various alkyl phosphonium bromides with appropriate aldehydes in the presence of potassium tert-butoxide (t-BuOK) in anhydrous THF solution at room temperature served as the key step, and the result showed that only (Z)-configuration olefins were formed by this procedure. The synthesis of the (Z)-5-(trideca-4-enyl)resorcinol (1) was reported for the first time.     

Synthesis, Characterization and Crystal Structure of （＋）-N-[（3S）-3-（4- fluoroph enyl）heptan oyl] bornan e-10,2-s ultam

The chiral molecule (+)-N-[(3S)-3-(4-fluorophenyl)heptanoyl]bornane-10,2-sultam (C23H32FNO3S, Mr = 421.56), a fluorine-containing derivative of camphorsultam, was conveniently obtained and crystallized in the orthorhombic space group P212121 with a = 7.9044(11), b = 11.6680(16), c = 24.899(3) , V = 2296.4(5) 3, Z = 4, Dc = 1.219 Mg/m3, λ = 0.71073 , μ(MoKα) = 0.172 mm-1 and F(000) = 904. X-ray diffraction analysis reveals that the six-membered ring of sultam shows a boat conformation (Fig. 1). The planes constructed by ((C6), (C7), (C8), (C9)) and ((C4), (C5), (C6), (C9)) form a dihedral angle of 70.3(3)°. The plane of (C1)-(C2)-(C3) forms dihedral angles to the aforementioned planes of 85.9(4) and 89.5(4)°, respectively. The molecules are linked via C-H···O/F interactions.     

Synthesis,and Experimental and Theoretical Characterization of 3-（4-（Dimethylamino） benzylidene）-l,5-dioxaspiro [5.5] Undecane-2,4-dione

The title molecule, 3-（4-（dimethylamino）benzylidene）-l,5-dioxaspiro[5.5] unde- cane-2,4-dione （I）, was synthesized and characterized by elemental analysis, IR, UV-vis spectra and X-ray diffraction analysis. The compound belongs to the triclinic system, space group Pi with a = 6.3640（6）, b = 7.7404（8）, c = 16.2890（18） A, α = 86.860（2）, β = 85.837（2）, γ = 79.6720（10）°, V = 786.60（14） A3, D, = 1.331 g/cm3, and F（000） = 336. Geometrical structure of the title compound was optimized by density functional theory （DFT） using B3LYP method with 6-31G＊＊ as the basis set. The vibrational frequencies were calculated by the DFT method and the results are consistent with the observed frequencies. The electronic absorption spectra were studied with the time- dependent density functional theory （TD-DFT）, showing the calculation results in good agreement with the corresponding experimental data.     

Synthesis and Structural Characterization of Organophosphorus Ylide-1-(3-nitrophenyl)-2-(triphenyl phosphoranylidene)ethanone

The title compound Ph3P=C(H)C(O)PhNO2(L) has been prepared by the addition of triphenylphosphine in acetone as solvent to 2-bromo-1-(3-nitrophenyl)ethanone followed by the addition of alkaline solution of sodium hydroxide. The yellow crystals of the title ylide were grown in methanol/chloroform solution by drop method without stirring at room temperature. The solid state structure of ylide has been established by X-ray crystallography analysis. In the molecule of the title compound, the geometry around the P atom is nearly tetrahedral and the O atom is in synperiplanar orientation to the P atom. The nitrophenyl ring is twisted with respect to the plane of the carbonyl group through an angle of 36.6(1)°. The crystal(C26H20NO3P, Mr = 425.40) belongs to the monoclinic system, space group P21/n with a = 10.889(3), b = 14.467(3), c = 13.872(4) , β = 103.08(3)°, V = 2128.6(10) 3, Z = 4, T = 100(2) K, R = 0.059 and w R = 0.163 for 3984 observed reflections with Ⅰ 2σ(Ⅰ).     

Reaction of Ketene Dithioacetals with Pyrazolylcarbohydrazide： Synthesis and Biological Activities of Ethyl 5-Amino-1-（5＇-methyl-1 ＇-t-butyl-4＇-pyrazolyl）carbonyl-3-methylthio-1 H-pyrazole-4-carboxylate

The title compound, C16H23N5O3S, ethyl 5-amino-1-(5‘-methyl-1‘-t-butyl-4‘-pyrazolyl)carbonyl-3-methylthio-1H-pyrazole-4-carboxylate (5) has been synthesized by the treatment of ethyl 2-cyano-3,3-dimethylthioacrylate with 1-t-butyl-5-methyl-4-hydrazinocarbonylpyrazole (4) in refluxed ethanol. The possible mechanism of the above reaction was also discussed. The results of biological test show that the title compound has fungicidal and plant growth regulation activities.     

Thermal Behavior and Decomposition Kinetics of the Complexes of CuX2 （X=NO3, Br, CI and CIO4） with 3,3＇-Dimethyl-1 -（1 H-1,2,4-triazol-1-yl）-2-butanone

The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3‘-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X=Br or Cl) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC, EDS and elemental analysis techniques. The resuits showed that their decomposition proceeded in three different ways mainly depending on the anions in the molecules. The heat effect associated with the decomposition step of DMTZB molecules was also different. The decomposition mechanisms and the kinetic parameters of DMTZB were determined and calculated by jointly using four methods, which showed that its pyrolysis was controlled by D3 mechanism but with different activation energies and pre-exponential factors for different complexes.     

基于1,2-二氢-2-(4-羧基苯基-4-[4-(4-羧基苯氧基)-3-甲基苯基](2H)二氮杂萘-1-酮的新型芳香聚酰胺的简易合成

A new monomer diacid, 1,2-dihydro-2-(4-carboxylphenyl)-4-[4-(4-carboxylphenoxy)-3-methylphenyl]phtha-lazin-1-one (3), was synthesized through the aromatic nucleophilic substitution reaction of a readily available unsymmetrical phthalazinone 1 bisphenol-like with p-chlorobenzonitrile in the presence of potassium carbonate in N,N-dimethylacetamide and alkaline hydrolysis. The diacid could be directly polymerized with various aromatic diamines 4a-4e using triphenyl phosphite and pyridine as condensing agents to give five new aromatic poly(ether amide)s 5a-5e containing the kink non-coplanar heterocyclic units with inherent viscosities of 1.30-1.54 dL/g.The polymers were readily soluble in a variety of solvents such as N,N-dimethylformamide (DMF), N,N-dimethyl-acetamide (DMA), dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidinone (NMP), and even in m-cresol and pyridine (Py). The transparent, flexible and tough films could be formed by solution casting. The glass transition tem-peratures Tg were in the range of 286-317℃.     

Synthesis and Structural Characterization of 2,3-Bis（hydroxymethyl）-2,3-dinitro-1,4-butanediol

2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol(C6H12N2O8) was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the title compound was characterized by 1H NMR,13C NMR,FT-IR,elementary analysis,and X-ray single-crystal diffraction analysis,which reveals that the title compound crystallizes in triclinic,space group P with a = 0.6324(2),b = 0.6454(3),c = 0.7062(3) nm,α= 111.550(4),β= 95.505(4),γ= 113.395(4)°,V = 0.23595(16) nm3,Z = 1,Mr = 240.18,Dc = 1.690 g·cm-3,μ = 0.159 mm-1,F(000) = 126,R = 0.0304 and wR = 0.0907.     

NMR Parameters and Vibrational Investigation of 2-Dicyanovinyl-5-（4-ethoxyphenyl） thiophene by ab initio HF and DFT Calculations

Optimized geometry and harmonic vibrational frequency of 2-dicyanovinyl-5-(4- ethoxyphenyl)thiophene (C16H12N2OS) are calculated at the HF/6-31++G(d,p) and B3LYP/6- 311++G(d,p) levels. Mulliken charges in the ground state are also calculated. The research shows the presence of intermolecular interaction in the title compound. The scaled harmonic vibrational frequencies have been compared with experimental FT-IR spectra. A detailed interpretation of the infrared spectra of the title compound is reported. The theoretical spectrograms for IR spectra of the title compound have been constructed. The isotropic chemical shift computed by 13C and 1H NMR analyses also shows good agreement with the experimental observations.