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1.
竹文坤  罗学刚  张驰  周建 《无机化学学报》2011,27(10):2053-2060
利用巴斯德芽孢杆菌繁殖过程产生的酶化作用,适时引入Ba2+,形成碳酸钡沉淀,通过用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、综合热分析仪(DSC-TG)对碳酸钙样品形貌、结构、热性质等进行表征。结果表明,巴斯德芽孢杆菌诱导沉淀的碳酸钡与纯水中的不同,含有少量有机物质,晶形转变温度降低。主要为花簇状和放射状,属于正交晶系。菌体和代谢物在碳酸钡晶体成核、生长及堆积过程中扮演重要的角色。  相似文献   

2.
Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.  相似文献   

3.
Different morphologies of BaCO3 crystals with dendritic structure,spinous sphere structure,and spike-,flower-and rod-like structures were prepared with(C2H5)2CO3 and BaCl2.2H2O as raw materials by homogeneous precipitation method.The crystals have been characterized by SEM,FT-IR and XRD,indicating that the different morphology of BaCO3 crystals belongs to the orthorhombic crystal system with uniform distribution and integral shapes.The effect of reaction conditions and the possible formation mechanism on the morphology of BaCO3 crystals have been discussed.  相似文献   

4.
溴化四丁铵催化苯乙烯一步合成苯乙烯环状碳酸酯   总被引:1,自引:0,他引:1  
以溴化季铵盐为催化剂, 通过苯乙烯的环氧化和CO2的加成反应一步直接合成出苯乙烯环状碳酸酯, 详细考察了催化剂的用量、氧化剂的种类、反应温度、反应时间和CO2压力等因素对反应主产物收率的影响. 结果表明, 以溴化四丁铵为催化剂, 于80 ℃和1 MPa CO2下反应6 h, 环状碳酸酯的收率达到38%, 这是季铵盐阳离子和亲核性阴离子协同催化的结果.  相似文献   

5.
The biological mediation of mineral formation (biomineralization) is realized through diverse organic macromolecules that guide this process in a spatial and temporal manner. Although the role of these molecules in biomineralization is being gradually revealed, the molecular basis of their regulatory function is still poorly understood. In this study, the incorporation and distribution of the model intrinsically disordered starmaker-like (Stm-l) protein, which is active in fish otoliths biomineralization, within calcium carbonate crystals, is revealed. Stm-l promotes crystal nucleation and anisotropic tailoring of crystal morphology. Intracrystalline incorporation of Stm-l protein unexpectedly results in shrinkage (and not expansion, as commonly described in biomineral and bioinspired crystals) of the crystal lattice volume, which is described herein, for the first time, for bioinspired mineralization. A ring pattern was observed in crystals grown for 48 h; this was composed of a protein-enriched region flanked by protein-depleted regions. It can be explained as a result of the Ostwald-like ripening process and intrinsic properties of Stm-l, and bears some analogy to the daily growth layers of the otolith.  相似文献   

6.
In the structure Ba12F19Cl5 [hexagonal space group P6 2m] the two chlorides on the sites Cl(1) and Cl(2) can partially be replaced by bromide ions. Single crystals of the type Ba12F19ClδBr5–δ with a chloride to bromide ratio up to 2 : 3 could be obtained by cooling a flux of 75 mol% BaF2 and 25 mol% BaX2 with X = Cl, Br. The crystal quality decreases with increasing bromide concentration. Structural parameters of five selected single crystals with different chloride/bromide ratio were studied by single crystal X-ray diffraction methods. The refined total Cl?/Br? population ratio in the crystals is close to the one of the flux. The lattice parameters and interatomic distances change in various ways, when the smaller chloride ion is replaced by the bigger bromide ion. The refinements show a statistical disorder on the halide sites with preferential bromide substitution on site Cl(1).  相似文献   

7.
In the synthesis of InPO4 crystals, using F127 [(EO)106(PO)70(EO)106] as a structure‐directing template, a morphology tunable progress was observed during the crystal evolution. By verifying the initial pH from 1.0 to 12.0, the morphology is evolved from single crystal, through sub‐micro crystallites, and finally to crystalline nanoparticles. The most influential factors in the morphology evolution are the initial pH level, the participation of surfactant‐template F127, and the change in pH during the reaction.  相似文献   

8.
9.
Abstract

Reaction of VO(acac)2 with the hydrazone ligands N’-(2-hydroxybenzylidene)-3methylbenzohydrazide (H2L1) and N’-(2-hydroxybenzylidene)-3-methyl-4-nitrobenzohydrazide (H2L2) afforded two oxidovanadium(V) complexes, [VOL1(OMe)(MeOH)] (1) and [VOL2(OEt)(EtOH)] (2), respectively. The complexes have been characterized by elemental analyses, IR, UV-Vis, molar conductivity and X-ray single crystal diffraction techniques. The hydrazone ligands coordinate to the V ions through the phenolate oxygen, imino nitrogen and enolate oxygen atoms. The V ions in both complexes are in octahedral coordination, with the three donor atoms of the hydrazone ligands, and with the other three sites furnished by one methanol or ethanol oxygen atom, one deprotonated methanol or ethanol oxygen atom, and one oxo oxygen. The complexes were assayed for their antibacterial activity on the bacteria B. subtilis, E. coli, P. putida and S. aureus.  相似文献   

10.
Crystals of Ba3ZnSb2O9 have been grown by a high-temperature solid-state reaction and characterized by single-crystal X-ray diffraction.Ba3ZnSb2O9 crystallizes in the hexagonal P63/mmc space group with a = 5.8663(4),c = 14.478(2) ,V = 431.49(8) 3,Z = 2 and R(all data) = 0.0167.The structure of Ba3ZnSb2O9 consists of pairs of face-sharing Sb2O9 bi-octahedra connected via corners with two single layers of mutually isolated ZnO6 octahedra.Each Ba2+ ion is bonded to 12 oxygen atoms.The UV-vis absorption spectrum of the compound has been investigated.Additionally,the calculations of band structure and density of states have also been performed with density functional theory method.The obtained results tend to support the experimental data of the absorption spectrum.  相似文献   

11.
通过串联迈克尔加成-消除反应合成了N,N'-二-[5-甲氧基-3-溴-2(5H)-4-呋喃酮基]-1,2-乙二胺,利用IR、UV、1H NMR、13C NMR、MS、元素分析和X射线单晶衍射对其进行表征.X射线单晶衍射结果表明:标题化合物包含两个平面的呋喃酮环和两个手性中心,并通过N(1)-H(1A)…O(1)分子间氢键和Br(1)…O(2)近距离作用形成超分子结构.  相似文献   

12.
Two holy water fonts (dated at the beginning of the XVII century) in the Santa Maria della Steccata Church in Parma (Italy) have recently been restored. Before the intervention, a detailed investigation on their degradation products was carried out to understand the mechanisms of alteration of the materials and to suggest appropriate restoration procedures.The analyses were performed by means of powder X-ray diffraction (XRD), micro-Fourier transform infrared (FTIR) and micro-Raman spectroscopies. Calcite, iron oxides, silicates and sodium chloride (from salted holy water) were found in the red coloured calcarenite. On and under the lead coverings, different lead oxides (mainly massicot), other lead salts (lead basic carbonate, cerussite, plumbonacrite Pb10O(OH)6(CO3)6 and lead-chlorine compounds as laurionite PbOHCl and phosgenite Pb2CO3Cl2) were identified by Raman spectroscopy and XRD. Haematite α-Fe2O3, goethite α-FeO(OH) and lepidocrocite γ-FeO(OH) were found on and around the iron hinges.Lead compounds and sodium chloride, through crystallization and solubilization cycles, were responsible for the stone's degradation, whereas the iron corrosion materials on the hinges produced mechanical stress and cracks in the stone.Various suggestions have been given on how to restore these fonts and to remove the causes of damage.  相似文献   

13.
合成了N,N’-二[3-氯-5S-(l-孟氧基)-2(5H)-4-呋喃酮基]-1,4-丁二胺,并通过IR,^1H NMR,MS和X射线单晶衍射对其进行了表征.X射线单晶衍射结果表明:标题化合物的不对称结构单元中包含一个平面的呋喃酮环和一个椅式的环己烷环,四个手性中心.标题化合物通过N—H…O分子间氢键作用实现空间堆积.  相似文献   

14.
15.
Hexagonal Al-doped zinc oxide (ZnO) powders with a nominal composition of Zn1-xAlxO (0≤x≤0.028) were synthesized by the co-precipitation method. The contents of the Al element in the samples were measured by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) technique. The structures of the Zn1-xAlxO (0≤x≤0.028) compounds calcined at 1000 and 1200℃ have been deter- mined using the Rietveld full-profile analysis method. Rietveld refinements of the diffraction data indi- cated that the addition of Al initially has a considerably positive effect on the decreasing of the lattice parameters a and c of Zn1-xAlxO, but the effect becomes very slight and even negative with the further increase of the Al content. The solid solubility limit of Al in ZnO (mole fraction y) is 2.2l%, resulting in Zn0.978Al0.22O. It seems that when the Al content is excessive, Al prefers to form a ZnAl2O4 compound with ZnO, but not to incorporate into the ZnO lattice to occupy the Zn2 cites. Two phases, [ZnO] (or Al-doped ZnO) and [ZnAl2O4], are obviously segregated in Zn1-xAlxO while the value of x is larger than 0.024. The UV-Vis absorption spectra show that the Al-doped ZnO exhibits a red-shift in the absorption edge without reduced transmission compared with pure ZnO, which also confirms that Al ions enter the ZnO lattice and form a Zn1-xAlxO solid solution.  相似文献   

16.
本文合成了2个双氧钒(Ⅴ)配合物,[VO2L1](1)和[VO2L2]2(2)(L1=4-氯-2-[(2-苯胺基乙亚胺基)甲基]苯酚盐;L2=4-[2-(2-{[1-(5-氯-2-羟基苯基)甲亚胺基]胺基}乙胺基)乙亚胺基]-2-戊酮),并通过物理化学方法和单晶X-射线衍射表征了它们的结构。在单核配合物1中,V原子采取畸变的四方锥配位构型,在双核配合物2中,V原子采取八面体配位构型。研究了这2个配合物对幽门螺旋杆菌脲酶的抑制活性。在浓度为100μmol.L-1时,配合物1和2对脲酶的抑制率分别为(52.1±1.8)%和(34.2±3.3)%。还做了配合物和幽门螺旋杆菌脲酶的分子对接研究。配合物的结构和其抑制脲酶活性的关系表明,配合物分子的尺寸和形状对脲酶的抑制作用具有重要影响。  相似文献   

17.
1 INTRODUCTION Recently, compounds containing pyrazole, imida- zole, triazole (including benzotriazole), pyridine, tetrazole and indole have attracted much interest because of their fungicidal activity, plant-growth regulating activity and antibacterial activity[1~3]. Schiff bases also constitute a good type of biolo- gically active substructures[4~7]. Studies of pyri- dine Schiff base-type fungicides have been repor- ted[8]. However, some structures of pyridine com- pounds containing h…  相似文献   

18.
《印度化学会志》2021,98(10):100168
The three new Cobalt(II) complexes [Co(L1)2(H2O)2] (1), [Co(L2)2(H2O)2] (2), and [Co(L3)2(H2O)2] (3) have been synthesized by interaction of acyl pyrazolone ligands, 4-(4-chlorobenzoyl)3-methyl1-phenyl1H-pyrazole5(4H)-one (HL1), 4-(4-chlorobenzoyl)1-(3-chlorophenyl)3-methyl1H-pyrazole5(4H)-one (HL2) and 5-methyl4-(4-methylbenzoyl)2-phenyl2,4-dihydro3H-pyrazole3-one (HL3) with CoCl2.6H2O. The complexes were screened using FTIR, UV–Vis, TGA, and Single Crystal X-ray diffraction spectroscopic techniques. A relative study of the ligands’ FTIR spectra and their metal complexes reveal the formation, sifting, and disappearance of several bands during complexation. Other interpretations stipulated that these three complexes are mononuclear and exhibited octahedral geometry around Co2+.Triclinic crystal system, Distortion in Octahedral geometry, and Intermolecular hydrogen bonding confirmed by Single-crystal XRD analysis of [Co(L3)2(EtOH)2] complex.  相似文献   

19.
Bis(o-nitrophenyl) carbonate reacts under mild conditions with chirals 1,2-amino alcohols and, after addition of DMAP, affords the corresponding oxazolidin-2-ones in very good yields.  相似文献   

20.
New alkene liquid crystals 4-[oligo(ethylene oxide)o, monomethylether)carbonyl]phenyl 4-[4(allyloxy) phenyl]benzoate(MBPBEn, n = 1-3), 4′-[oligo(ethylene oxide)o, monomethylether)carbonyl]biphenyl-4-yl 4-[4-(al1yloxy)phenyl]benzoate(MBPBPEn, n = 1-3), (S)-4-[(2-methyl-I-butoxy)carbonyl]phenyl 4[4-(allyloxy)phenyl]benzoate(MBPBKA), and (S)-4′-[(2-methyl-l-butoxy)carbonyl]biphenyl-4-yl 4-[4(allyloxy)phenyl]benzoate(MBPBPKA) were synthesized and characterized using 1H-NMR and elemental analysis methods. The thermal transition temperatures, mesomorphic properties, and mesophase textures of these compounds have been determined by differential scanning calorimetry (DSC), by polarizing optical microscopy, and by X-ray diffraction analysis. The effect of changes in chemical structure on the mesophase properties, mesophase and isotropic transition temperatures, and mesophase textures are discussed.  相似文献   

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