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1.
采用等温溶解法测定了偏钒酸铵(NH4VO3)在NH4H2PO4-H2O和(NH4)3PO4-H2O体系中T = 298.15-328.15 K时的溶解度以及溶液的密度和pH值。结果表明, NH4VO3的溶解度随着(NH4)3PO4或NH4H2PO4溶液浓度的增大,先降低后升高,这是由于同离子效应、化学反应平衡及离子活度的共同作用。比较T = 298.15K时, NH4VO3分别在NH4H2PO4-H2O、(NH4)2HPO4-H2O和(NH4)3PO4-H2O体系中溶解度,发现在相同的磷酸盐浓度下, NH4VO3的溶解度在NH4H2PO4-H2O体系中最大,在(NH4)3PO4-H2O体系中居中,在(NH4)2HPO4-H2O体系中最小。进一步地,在T = 298.15 K和磷酸盐浓度C = 0.5 mol·kg-1时,结合pH值和反应溶度积常数KSP等计算三个体系中的平均离子活度系数(γ±),发现γ±值在(NH4)2HPO4-H2O体系中最大,在(NH4)3PO4-H2O体系中居中,在NH4H2PO4-H2O体系中最小,与溶解度规律一致。 相似文献
2.
The title compound 4-methyl-4-hydroxy-2-pentone is obtained by the condensed reaction of acetone, and co-crystallized with octamolybdate anion and tetrabutyl-ammonium cation. The crystal structure belongs to triclinic system, space group P1, Mo8C44H98O30N2 Mr= 1902.77, a=11. 512(6), b=12. 790(3), c=13. 395(4)A, α=65. 22(2), β=78. 26(4), γ=71. 12(3), V=1689(1) A3, Z=1, Dx=1. 869g/cm3, F(000)=950, μ=14.79 cm-1, final R=0. 053 and Rw=0. 067. Theorbital hybridization of C (53) and C (55) are sp3 and sp2 separately in (CH3)2COHCH2COCH3 and the catalysis of β-octamolybdate anion might be present for the condensed reaction of acetone. 相似文献
3.
引入SiO2对SO4^2—/ZrO2超强酸体系的影响 总被引:11,自引:0,他引:11
用共沉淀法和负载法制备了一系列SO4^2-/ZrO2催化剂,详细研究了添加SiO2对SO4^2-/ZrO2超强酸样品的晶化、比表面、硫含量、超强酸性和异丙苯裂解及异丙醇脱水反应的影响。引入SiO2会延迟ZrO2的晶化和晶相转变,减弱SO4^2-/ZrO2体系的超强酸性,但对提高样品的异丙苯裂解和异丙醇脱水反应活性有利。 相似文献
4.
Recently, a new research realm in crystal engineering of supramolecular architecturesassembled by means of coordinate covalent bonding', hydrogen bonding', or other weakintermolecular interactions= has been rapidly expanding in order to rationally developnew classes of functional materials with cavities or pores. These types of compoundsmay exhibit interesting topological structures and the clathrations of the cavity structuresmay have many potential properties such as catalysis', electrical co… 相似文献
5.
提出了一种基于乙醇-电解质-水体系双水相萃取、固体基质室温燐光法(SS-RTP)测定色氨酸的新方法:将适量电解质和乙醇加入试液中,离心后用SS-RTP测定上相中的色氨酸.在最佳萃取体系乙醇-K2HPO4-KH2PO4-H2O中,测定色氨酸的线性范围1.0×10-7~2.0×10-6mol/L、检出限5.4×10-9mol/L(S/N=3).用于大豆、大米、玉米和竹笋中色氨酸的测定,相对标准偏差2.2%~3.3%,与荧光法比较,相对误差-3.3%~3.2%. 相似文献
6.
The reaction of Ni(CH3COO)2(6H2O, 4-hydroxycinnamic acid (Hhca) and 4,4'-bipyri- dine (bipy) ligand in water-solution afforded a mononuclear complex [Ni(H2O)4(4,4'-bipy)2](hca)2 which was characterized by IR, elemental analysis, TGA and single-crystal X-ray diffraction. X-ray crystallography analysis reveals that the complex is of triclinic, space group P with a = 7.0238(14), b = 7.2934(11), c = 17.186(4) (A), α = 87.073(13), β = 84.354(10), γ = 81.961(12)°, V = 866.9(3) (A)3, Z = 1, Dc = 1.474 g/cm3, F(000) = 402, μ = 62.7 mm-1, R = 0.0411, wR = 0.0862 and GOF = 1.048. In solid state, the cation [Ni(H2O)4(4,4'-bpy)2]2+ connects six nearby hca counter anions via O-H…O hydrogen bonds to form an extended 2D lattice framework and the O-H…N hydrogen bonds finally link the 2D layers into an infinite 3D network. 相似文献
7.
The reaction of 4,4′-diaminodiphenylmethane (dadm), malonic acid (H2mal) and Cu(NO3)2 in aqueous solution results in a discrete binuclear Cu(II) macrocycle: [Cu(dadm)(mal)- (H2O)]2(2H2O. It crystallizes in monoclinic, space group P21/c with a = 15.231(3), b = 11.847(2), c = 9.801(2)A,Z= 106.75(3)o, V = 1693.5(6)A3, Z = 2, C32H40Cu2N4O12, Mr = 799.76, Dc = 1.568 g/cm3, λ(MoK() = 0.71073A, μ = 1.325 mm-1, F(000) = 828, the final R = 0.0531 and Wr = 0.1244 for 3421 observed reflections with I > 2σ(I). Each Cu(II) is coordinated by two oxygen atoms from a mal ligand, two nitrogen atoms from two dadm ligands and a water oxygen atom to form a triangle bipyramidal motif. The title compound possesses a distorted macrocycle enclosed by dadm with approximate dimensions of 8.3A× 5.9A. 相似文献
8.
Afarin Moezzi Marylin M. Olmstead Doris C. Pestana Philip P. Power 《无机化学与普通化学杂志》1995,621(11):1933-1938
The reaction of either Li2PPh or Li2AsPh with the diborane(4) derivative B2(NMe2)2Br2 affords the compounds [PhP(BNMe2)2]2 ( 1 ) or [PhAs(BNMe2)2]2 ( 2 ) in good yield. Both 1 and 2 have cyclic structures featuring non-planar P2B4 or As2B4 six-membered rings which have chair configurations. Although all four borons in each ring have planar coordination, the two phosphorus or arsenic centers have different degrees of pyramidalization. Bond distances within the rings indicate that the B? B, B? P or B? As bonds are single, whereas the exo-B? N bond lengths are consistent with significant π-bonding. The ring structures of 1 and 2 are in sharp contrast to the related boron-nitrogen species (t-BuN)2N4Me4 which has a nido-N2B4 framework. The attempted synthesis of the nitrogen analogue of 1 or 2 by using a similar approach did not result in the isolation of [PhN(BNMe2)2]2, instead the tetramino diborane(4) species [B(NMe2)NHPh]2 ( 3 ), which has a structure similar to other tetramine diborane(4) compounds, was isolated. 相似文献
9.
4,5-二氢-1,3,4-噻二唑-5-酮-2-甲氨基取代氰基丙烯酸酯类化合物的 合成及生物活性研究 总被引:1,自引:0,他引:1
采用氰基丙烯酸酯与5-甲氧基-1,3,4-噻二唑-2-甲氨在乙醇中加热回流的方法合成了一系列4,5-二氢-1,3,4-噻二唑-5-酮-2-甲氨基取代的氰基丙烯酸酯类化合物. 目标化合物结构均经1H NMR, IR和元素分析确证. 生物活性测试结果表明: 部分化合物对双子叶杂草显示出较好的除草活性及良好的选择性, 化合物6j在1.5 kg/ha的剂量下对油菜的茎叶处理抑制率达到100%; 部分化合物还表现出了一定的杀菌和植物生长调节活性. 构效关系研究发现氰基丙烯酸酯3-位取代基的体积对除草活性影响较大, 3-位为异丙基时活性最高. 相似文献
10.
The title complex has been obtained by the reaction of cobalt sulfate heptahydrate
with 4,4'-bpy and 4-abaH (4,4'-bpy = 4,4'-bipyridine, 4-abaH = 4-aminobenzonic acid) in ethanol
solution, and its structure was determined by X-ray crystallography with the following data:
tetragonal, space group P42/n, Mr = 5692.46, Co8C192H288N32O120S8, a = b = 16.402(5), c =
22.750(5) (A), Z = 1, V = 6120(2) (A)3, F(000) = 2968, Dc = 1.544 g/cm3,μ = 0.707 mm- 1, the final R
= 0.0786 and wR = 0.1935 for 2673 observed reflections (I > 2σ(I)). The title complex consists of
polymeric [Co(4,4'-bipy)(H2O)4]2+ cation chains, SO42- anions, lattice 4-abaH and water mole
cules. The center CoⅡ ions are connected by bridging 4,4'-bpy ligands exhibiting one-dimensional
chains, and coordinated by four water molecules into a distorted octahedral geometry. These chains
are further extended by hydrogen bonds among SO42- anions, coordinated and lattice water
molecules as well as lattice 4-abaH molecules into a three-dimensional network. 相似文献
11.
1 INTRODUCTION The rational design and synthesis of new metal- organic frameworks have generated considerable interest in supramolecular chemistry and materials science owing to their intriguing structural diver- sities and potential applications as functional mate- rials[1~6]. Carboxylate-containing ligands have attrac- ted considerable attention because of the various coordination modes of carboxylate group, the ability to form hydrogen bonds and the potential applica- tions as functio… 相似文献
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13.
V. N. Britsun A. N. Borisevich A. N. Esipenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2006,42(4):546-550
The products of cyclocondensation of 3-oxo-3-R1-N-R2-propanethioamides with 3-aryl-2-propenoyl chlorides in acetone in the presence of potassium carbonate are 5-acyl-1-aryl(alkyl)-4-aryl-6-thioxopiperidin-2-ones,
5-acyl-2-aryl-6-aryl(alkyl)amino-2,3-dihydro-4H-thiopyran-4-ones, and 2-acetonylidene-3,6-diaryl-5,6-dihydro-4H-1,3-thiazin-4-ones,
the structure of which is proven by both spectral methods and chemical conversions.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 623–628, April, 2006 相似文献
14.
15.
Ming Wu DING* Jing ZHU Su Fang SHI Xiao Peng LIU Institute of Organic Synthesis Central China Normal University Wuhan Department of Chemistry Central China Normal University Wuhan Center of Analysis Testing Central China 《中国化学快报》2002,13(10)
Many N-heterocycles including 4H-imidazolin-4-ones exhibit biological activities1-3. Some derivatives of 5-(2-furfurylidene)-4H-imidazolin-4-one were found to show good antiinflammatory activity4. They can be synthesized by condensation of furfural with 5- unsubsituted 4H-imidazolin-4-ones or from corresponding oxazolones5,6. However, no synthesis of 2-aryloxy substituted 5-(2-furfurylidene)-4H-imidazolin-4-one was reported. Recently, aza-Wittig reaction has received increased attention … 相似文献
16.
Hue T. B. Bui Duy D. Vo Yen N. T. Chau Cuc T. K. Tu Hieu V. Mai Kiet V. Truong 《合成通讯》2013,43(24):2861-2868
A facile synthetic method for the construction of 2-substituted-4-oxo-4H-quinolizine-based core structure has been successfully developed. The synthesis made use of a one-pot Stobbe condensation followed by cyclization starting from the commercially available 2-pyridinecarbaldehyde. The structure of the formed 4-oxo-4H-quinolizine-2-carboxylate was fully confirmed by mass spectra, 1H NMR and 13C NMR, correlation spectrography, heteronuclear multiple bond correlation, and heteronuclear single quantum coherence (HSQC) spectra. The ethyl carboxylate moiety was then further functionalized via direct aminolysis by a range of amines to afford the corresponding 4-oxo-4H-quinolizine-2-carboxamides 4a–i in moderate to good yields. 相似文献
17.
1 INTRODUCTION Recently the self-assembly through transition metal and N-containing organic ligands has appear- ed as a popular research field in supramolecular architecture. Among the N-donor organic ligands, the rigid ligands have been well investigat… 相似文献
18.
以4-叔丁基吡啶为原料,与碘甲烷成盐后经铁氰化物氧化,在吡啶环上引入酮基,再经溴代、巯基化得标题化合物。由原料到溴代物的合成总收率达80%。 相似文献
19.
1 INTRODUCTION A great deal of interest in transition metal com- plex assembly has recently been devoted to the development of rational synthetic routes to novel one-, two- and three-dimensional crystal frameworks, due to their potential applications in… 相似文献
20.
Jérôme Dauvergne Vasudev Jadhav Marie-Christine Matos Michael R Pitts Sanjay K Singh John Whittall 《Tetrahedron》2004,60(11):2559-2567
Three different methods are reported for the preparation of 4-azacyclo-2-enones 1, two of which allow the preparation of the compounds in optically active form. In addition, a facile route to 4-aza-5,5-dimethylcyclopent-2-enones 2 is disclosed. 相似文献