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1.
A series of novel organically templated germanium antimony sulfides have been solvothermally synthesized and structurally, thermally, and optically characterized. The compound [Me2NH2]6[(Ge2Sb2S7)(Ge4S10)] ( 1 ) features two distinct tetranuclear [Ge2Sb2S7]2? and [Ge4S10]4? isolated clusters. The compound [(Me)2NH2][DabcoH]2[Ge2Sb3S10] ( 2 ) (Dabco=triethylenediamine) features a 1D‐[Ge2Sb3S10]n3n? ribbon constructed with two [GeSbS5]n3n? chains bridged by Sb3+ ion in ψ‐SbS4 configuration. Compounds [M(en)3][GeSb2S6] (M=Ni ( 3 ), Co ( 4 ) en=ethylenediamine) feature the unique 2D grid layer structures of [GeSb2S6]n2n?. The compound [(Me)2NH2]2[GeSb2S6] ( 5 ) previously reported by us features a 3D chiral microporous structure with the chiral channels. The optical absorption spectra indicate that all the compounds are wide bandgap semiconductors. Thermal stabilities of these compounds have been investigated by thermogravimetric analyses (TGA).  相似文献   

2.
极弱酸碱的pH滴定法研究   总被引:7,自引:1,他引:7  
pH滴定法是指酸碱滴定至某一指定pH值时,即可根据滴定剂浓度,用量及有关公式,计算被测物浓度或含量的方法。本文深入讨论了测定原理,方法和应用,对10种不同极弱酸碱进行了大量测定,测定结果相对误差一般在0.2%左右,相对标准偏差在0.3%左右,达到化不。pH滴定法具有简便,价廉,快速和通用的优点,为直接滴定极弱酸碱和化学分析仪化开辟了新的途径。  相似文献   

3.
周万里  许岩 《无机化学学报》2011,27(12):2507-2512
通过溶剂热技术合成了一种以二亚乙基三胺(dien)为模板的链状结构硫酸钬(H3dien)[Ho(SO4)3(H2O)2] (1),并通过X射线分析、红外光谱、元素分析和粉末衍射进行了表征。X射线晶体结构分析,化合物1结晶于单斜晶系,P21/c空间群,a=0.660 20(13) nm,b=1.476 7(3) nm,c=1.655 6(3)nm,β=93.313(2)°,V=1.611 4(5) nm3,Z=4。化合物1是由HoO8多面体和SO4四面体为建筑单元构建成新颖的单一链状结构。在a轴方向上,配位水分子通过氢键连接相邻的链形成三维超分子结构。有机胺分子镶嵌于链间,在合成化合物1合成过程中,pH值(pH=1.5)起了关键作用。  相似文献   

4.
The arsenic(III) and antimony(III) cyanides M(CN)3 (M=As, Sb) have been prepared in quantitative yields from the corresponding trifluorides through fluoride–cyanide exchange with Me3SiCN in acetonitrile. When the reaction was carried out in the presence of one equivalent of 2,2′‐bipyridine, the adducts [M(CN)3 ? (2,2′‐bipy)] were obtained. The crystal structures of As(CN)3, [As(CN)3 ? (2,2′‐bipy)] and [Sb(CN)3 ? (2,2′‐bipy)] were determined and are surprisingly different. As(CN)3 possesses a polymeric three‐dimensional structure, [As(CN)3 ? (2,2′‐bipy)] exhibits a two‐dimensional sheet structure, and [Sb(CN)3 ? (2,2′‐bipy)] has a chain structure, and none of the structures resembles those found for the corresponding arsenic and antimony triazides.  相似文献   

5.
Glycoluril derivatives bearing free ureidyl groups (1) and bis(cyclic ethers) (2) are the fundamental building blocks for the synthesis of cucurbituril, its derivatives, and its congeners. The known derivatives of 1 and 2 fall into two main classes—those bearing alkyl or aryl functional groups on their convex face. In this paper we present a third class of glycolurils, namely those bearing substituents that are electron withdrawing in character. This class of compounds carries carboxylic acid derived functional groups on their convex face and are derived from diesters 1e and 2e. An improved synthesis of 1e and 2e is reported and their modification described. For example, 1e and 2e are converted into secondary amides (10-15) by heating in solutions of the neat primary amines. The secondary amides can be transformed into imides (19-22, 24, 25) by heating with PTSA in ClCH2CH2Cl. The isolation of these compounds in pure form in high yields is accomplished by simple and scalable washing or recrystallization procedures. We also present the X-ray crystallographic characterization of bis(cyclic ethers) 2e, 8, and 22. We anticipate that the ready availability of ester, carboxylate, acid, secondary amide, imide, and tertiary amide derivatives of 1 and 2 will expand the scope of the synthesis of cucurbituril derivatives by providing a new class of building blocks with electron withdrawing substituents.  相似文献   

6.
以2-氨基对苯二甲酸根离子(AT)为配体,合成了3个结构新颖的镉配位聚合物:[Cd(AT)(H2O)]n(1)、[Cd(AT)(Py)]n(2)和[Cd(AT)(BPP)]n(3)(AT=2-氨基对苯二甲酸根离子,Py=吡啶,BPP=1,3-二(4-吡啶基)丙烷)。晶体结构表明,随着辅助配体的改变,AT表现出3种不同的配位模式,分别形成rtl(1)、ths(2)和sql(3)3种不同的拓扑结构。由于分子内/分子间氢键、芳香环之间的π…π堆积与C-H…π相互作用,使得3个化合物展现出较好的热稳定性。  相似文献   

7.
以2-氨基对苯二甲酸根离子(AT)为配体,合成了3个结构新颖的镉配位聚合物:[Cd(AT)(H2O)]n1)、[Cd(AT)(Py)]n2)和[Cd(AT)(BPP)]n3)(AT=2-氨基对苯二甲酸根离子,Py=吡啶,BPP=1,3-二(4-吡啶基)丙烷)。晶体结构表明,随着辅助配体的改变,AT表现出3种不同的配位模式,分别形成rtl(1)、ths(2)和sql(33种不同的拓扑结构。由于分子内/分子间氢键、芳香环之间的ππ堆积与C-H…π相互作用,使得3个化合物展现出较好的热稳定性。  相似文献   

8.
A novel synthetic method for the preparation of aliphatic aldehydes from the corresponding carboxylic acids via 1,3‐dimethylbenzimidazolium salts is provided. 1,3‐Dimethylbenzimidazolium salts were rapidly reduced with sodium/ethanol and then hydrolyzed with hydrochloric acid to obtain aliphatic aldehydes, in which the 1,3‐dimethylbenzimidazolium salts can be readily achieved from the corresponding carboxylic acids. The mechanism for the reductive reaction of 1,3‐dimethylbenzimidazolium salts with sodium/ethanol was discussed.  相似文献   

9.
开小明 《大学化学》2006,21(2):63-64
讨论了强酸和弱酸混合溶液直接滴定的条件,并绘制了混合溶液滴定曲线,为强酸和弱酸混合溶液的滴定提供了理论根据。  相似文献   

10.
Two dinuclear nickel(Ⅱ) complexes [Ni2(teta)3]Cl4'2H2O1 and [Ni2(teta)3](NO3)4 2 (teta = triethylenetetramine) were synthesized by a solvothermal method and structurally characterized. Complex 1: orthorhombic, Pbca, a = 13.791(3), b = 13.078(3), c = 18.323(4) ,A, V = 3304.8(12) A3, Z = 4, Mr= 733.98, Dc = 1.475 g/cm^3,μ = 1.500 mm^-1, F(000) = 1560, R = 0.0585 (I 〉 20(/)) and wR = 0.1243. Complex 2: orthorhombic, P212121, a = 7.8279(14), b = 14.209(3), c = 31.163(6)A, V = 3466.2(11)A3, Z = 4, Mr= 804.19, Dc = 1.541 g/cm^3,μ = 1.164 mm^-1 F(000) = 1704, R = 0.0401 and wR = 0.0840 for 5950 observed reflections (I 〉 2σ(I)). Two Ni^2+ ions are connected by one linear bridging teta ligand, forming a dinuclear [Ni2(teta)3]^4+ cation. Each Ni^2+ ion in 1 and 2 takes a distorted octahedral geometry with six coordinated N atoms from two teta ligands. The effect of different anions on the arrangement of [Ni2(teta)3]^4+ cations has been discussed in view of H-bonding interactions. Thermal stability of 1 and 2 was also investigated.  相似文献   

11.
利用溶剂热法合成了2种四元硫化物Rb2CdSbS3(SH)(1)和Rb2HgSb4S82)。单晶X射线衍射分析表明,化合物1为一维链状结构,由[CdSbS3(SH)]2-阴离子和Rb+阳离子组成。化合物2为二维层状结构,由[HgSb4S8]2-阴离子和Rb+阳离子组成。固体紫外可见漫反射光谱分析结果表明,化合物12的带隙分别为2.06和2.15 eV。荧光分析结果表明化合物12均具有黄光发射特性。  相似文献   

12.
朱国贤  闫景辉  莫凤珊  石春山 《合成化学》2005,13(6):543-545,606
用水热和溶剂热法(甲苯作溶剂)合成了LiSrAlF6单相多晶。研究了反应物摩尔比、反应温度和反应时间等对产物的影响。采用环境扫描电子显微镜观察到LiSrAlF6晶体的形貌特征为六角晶形,并聚集成花朵形。试探了LiCaAlF6多晶粉末的水热和溶剂热合成,但未能获得纯相产物。  相似文献   

13.
New hydrated potassium hexaborate K2[B6O9(OH)2] has been synthesized under mild solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by FT-IR, Rarnan spectra and DTA-TG. It crystallizes in the monoclinic system with space group P21/n, a=0.9036(2) nm, b=0.66052(18) nm, c=1.5997(4) nm, β=91.862(4)°, V=0.9543(4) nm^3 and Z=4. Its crystal structure consists of K-O polyhedra and 1-D stepped polyborate chains constructed by new [B6O9(OH)2]2- fundamental building blocks. 1-D polyborate chains contain 3,8-membered boron rings. Adjacent chains are further linked via H-bonding interactions into 2-D layers. The K^+ cations reside not only between the layers but also in the 8-membered boron rings of the chains, compensating the negative charges of the borate chains and holding the layers together into the 3-D structure through bonding with oxygen atoms of the chains.  相似文献   

14.
Zinc glutarates were synthesized from zinc oxides with varying purities via different stirring routes. The particle size and structure of these zinc glutarates were determined by wide‐angle X‐ray diffraction, transmission electron microscopy, and the laser particle size analyzer technique. The results demonstrated that the crystallinity and crystalline perfectness of zinc glutarate are the crucial factors that affect the catalytic activity for the copolymerization of carbon dioxide (CO2) and propylene oxide (PO). Additionally, the catalyst with a small particle size dramatically increased the yield of the copolymerization between CO2 and PO. High‐molecular‐weight and regular molecular structure poly(propylene carbonate)s (PPC)s were obtained from CO2 and PO with the synthesized zinc glutarates. Very high catalytic activity of 160.4 g polymer/g catalyst was afforded. The NMR technique revealed that the PPC copolymer exhibits an exact alternating copolymer structure. The relationships between the crystallinity and the particle size of catalyst with the catalytic activity are correlated and discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3579–3591, 2002  相似文献   

15.
The present paper covers electronic structures and spectra of the bases and the base pairs of nucleic acids calculated by using the INDO/S method. For free bases we give the energy levels of ground states and transition energies of low-lying excited states and discuss the band characters. The results indicate that the calculated spectra are in good agreement with experimental values. On the other hand, our calculations for A-T and G-C pairs are very beneficial to understanding hydrogen bond properties of these pairs.  相似文献   

16.
由于在电学、磁学、光学、吸附、离子交换和催化等领域具有潜在的应用价值,具有开放骨架结构的金属磷酸盐的合成一直受到人们的广泛关注。在这些磷酸盐微孔化合物中,磷酸锌晶体是拓扑结构最为丰富的一种犤1犦。自从Stucky等犤2犦报道具有SOD、Li-ABW、FAU等已知结构磷酸锌的合成以来,已经有近百种具有0-D犤3,4犦,1-D犤5,6犦,2-D犤7~9犦,3-D犤10~13犦结构的磷酸锌被成功地合成出来。其中令人瞩目的是具有螺旋孔道的手性磷酸锌犤14犦以及具有二十四元环孔道的两种微孔磷酸锌化合物犤15,16犦的合成。这些化合物大多是采用水热技术以有…  相似文献   

17.
Two dinuclear nickel(II) complexes [Ni2(teta)3]Cl4·2H2O 1 and [Ni2(teta)3](NO3)4 2 (teta = triethylenetetramine) were synthesized by a solvothermal method and structurally characterized. Complex 1: orthorhombic, Pbca, a = 13.791(3), b = 13.078(3), c = 18.323(4) , V = 3304.8(12) 3, Z = 4, Mr = 733.98, Dc = 1.475 g/cm3, μ = 1.500 mm-1, F(000) = 1560, R = 0.0585 (I > 2σ(I)) and wR = 0.1243. Complex 2: orthorhombic, P212121, a = 7.8279(14), b = 14.209(3), c = 31.163(6) , V = 3466.2(11) 3, Z = 4, Mr = 804.19, Dc = 1.541 g/cm3, μ = 1.164 mm-1, F(000) = 1704, R = 0.0401 and wR = 0.0840 for 5950 observed reflections (I > 2σ(I)). Two Ni2+ ions are connected by one linear bridging teta ligand, forming a dinuclear [Ni2(teta)3]4+ cation. Each Ni2+ ion in 1 and 2 takes a distorted octahedral geometry with six coordinated N atoms from two teta ligands. The effect of different anions on the arrangement of [Ni2(teta)3]4+ cations has been discussed in view of H-bonding interactions. Thermal stability of 1 and 2 was also investigated.  相似文献   

18.
用低温溶剂热法合成了2种分立结构的有机杂化硫代碲(Ⅳ)酸盐化合物(H2en)TeS31)和[Ni(en)3]TeS32)(en=乙二胺),通过X-射线单晶衍射,红外光谱,元素分析等手段对它们的结构进行了表征。晶体结构解析结果表明:2个化合物均属单斜晶系,空间群分别为P21P21/c。化合物12具有孤立三角锥[TeS3]2-阴离子,化合物1的平衡阳离子为双质子化乙二胺[H2en]2+,阴离子基团[TeS3]2-和阳离子基团[H2en]2+之间通过N-H…S氢键连接。化合物2的阳离子基团为过渡金属Ni与乙二胺的配合物[Ni(en)3]2+。另外,对该2种晶体进行了紫外-可见漫反射光谱测试和热重分析。  相似文献   

19.
报道了一种新颖的L-氨基酸席夫碱的制备方法.L-丙氨酸(L-ala),L-丝氨酸(L-ser),L-缬氨酸(L-val),L-亮氨酸(L-leu),L-异亮氨酸(L-Ile),L-苯甘氨酸(L-phg),L-苯丙氨酸(L-phe)七种氨基酸与水杨醛或2-羟基-1-萘醛在氢氧化钾存在下,室温研磨得到相应的氨基酸席夫碱.所得产品经核磁共振氢谱、碳谱、红外光谱、质谱、元素分析等检测手段进行结构表征.实验结果表明,该反应室温只需10 min即可进行完全,产品纯度好,收率大于90%.  相似文献   

20.
采用溶剂热法,在1,4-丁二胺中合成以碱金属为客体阳离子的硫属锡酸盐Cs_8Mn_4Sn_4Se_(16)(1)及1,2-丙二胺(1,2-dap)配位的过渡金属为客体阳离子的硫属锡酸盐[Ni(1,2-dap)_3]_2Cd_2Sn_2S_8(2)。并采用单晶X射线、紫外可见漫反射、热重分析-差示扫描量热分析(TG-DSC)等手段进行表征。结果表明,化合物1为正交晶系,空间群为Fddd;化合物2为正交晶系,空间群为Cmcm;且结构中均包含Sn Q4(Q=S,Se)四面体与TMQ_4(TM=Mn,Cd)四面体通过共边而成的一维(1-D)阴离子链,紫外可见漫反射分析表明,化合物1、2的禁带宽度分别为1.70和2.21 e V,具有半导体性质。且TG-DSC测试显示化合物1、2在一定温度下具有一定的稳定性。  相似文献   

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