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1.
Crystalline [Dy(NCS)3(dibenzo-30-crown-10)(H2O)2]·H2O·MeCN can be obtained by slowly evaporating a reaction mixture of Dy(NCS)3·nH2O with dibenzo-30-crown-10 in a solution of acetonitrile. The material crystallizes in the monoclinic space groupP21/n, the cell parameters area=11.450(5),b=23.284(4),c=18.424(6)Å, =106.28(4)°,V=4715Å3,M=968.47,D x=1.36 g cm–1, =17.80 cm–1,F(000)=1972,Z=4.2740 independently observed [I3I] reflections were used in the final least-squares refinement leading to an agreement index ofR=0.085. The Dy(III) ion coordination geometry approximates a square antiprism, involving two water oxygens and three dibenzo-30-crown-10 oxygen atoms and three isthiocyanate nitrogens. Hydrogen bonds are formed between the two water molecules and four uncoordinated crown ether oxygen atoms. Supplementary Data relevant to this paper have been deposited with the British Library as Supplementary Publication No. SUP 82148 (22 pp.)  相似文献   

2.
Single crystal X-ray analysis of the 2:1 acetonitrile complex of 18-crown-6 is reported. Crystals of the complex are monoclinic,P21/n, witha=9.123(3),b=8.524(3),c=13.676(4) Å, =104.68(3)°, andD c =1.118 g cm–3 forZ=2. The complex lies on a center of symmetry, with the crown in theD 3d conformation. Methyl groups of the acetonitrile molecules have weak interactions with the crown oxygen atoms, and are tilted 31.7° from the host's threefold axis. Methyl hydrogen atoms are rotationally disordered about the acetonitrile axis. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82057 (12 pages).  相似文献   

3.
The single crystal of [Ba(H2O)2(C6H12O6)2Cl2] was obtained based on the phase equilibrium results. Its structure was determined by X-ray crystallographic analysis. The crystals are monoclinic and in space group C2/c with a=1.901 7(2) nm, b = 0.682 13(8) nm, c = 0.162 60(2) nm,β=96.593(2)°and V= 2.095 3(4) nm3, Z= 4, DC=1.917 g·cm-3. In its solid state, this supramolecular complex is a three-dimensional network with double layers connected by hydrogen bondings. The molecule structure of [Ba(H2O)2(C6H12O6)2Cl2] has a central barium ion that is coordinated to two water molecules, two chlorides, and four hydroxyls from the two inosi-tols. Losing the coordinating water is controlled by random nucleation and growth mechanism (n = 2/3) and 3-dimensional diffusion mechanism (n=2).  相似文献   

4.
六元瓜环与磺基水杨酸主客体配合物的晶体结构   总被引:1,自引:0,他引:1  
合成了六元瓜环与磺基水杨酸主客体配合物,并测定了其单晶结构.晶体结构表明六元瓜环包结了3个水分子,磺基水杨酸位于六元瓜环的外侧,且与水分子通过氢键与六元瓜环相连,瓜环之间通过端口的羰基O原子、磺基水杨酸以及水分子间的氢键作用形成一维超分子.  相似文献   

5.
Crystal structure of (C6H5NH3)3[SbCl5]Cl·H2O is determined by X-ray analysis (a = 9.4155(13) Å, b = 11.4344(16) Å, c = 13.1584(18) Å, α = 113.483(2)°, β = 90.383(2)°, γ = 97.323(2)°, space group P \(\bar 1\), Z = 2, ρcalc = 1.642 g/cm3). The crystal structure is based on [SbCl5]2? anions, anilinium cations (C6H5NH3)+, isolated Cl? anions, and water molecules. Structural features responsible for spectral and luminescent properties of the complex are discussed.  相似文献   

6.
1INTRODUCTIoNInrecentyears,researchesontheribosome-inactivatingproteins(RIPs)ex-tractedfromplantshavedrawnconsiderableattentionduetotheirhighlyspecialRNAN-glycosidaseactivityandtheiranti-HlVactivity"~".Theseproteinsinacti-vateenzymicallythelargesubunitofthemammalianribosomebythereleaseofA4324fromthe28Sr-RNAt4i.lthasbeenreportedthattheseproteinsalsoactonbac-terialandplantribosomes.Theirisolationandpurificationhavebeenstudiedinde-tail,andtheirpresentstatusandfutureprospectshavealsobeen…  相似文献   

7.
合成了以邻菲咯啉为配体的金属镉的配合物,利用红外光谱、元素分析、单晶衍射和热重分析等手段对其结构及性质进行了表征和分析,并研究了金属配合物对金黄色葡萄球菌、大肠杆菌、酵母菌的抑菌活性.结果表明,此类配合物对三类菌种均有不同程度的抑制作用.  相似文献   

8.
9.
The three-dimensional structure of trichosanthin crystallizing in space group C2 has beenrefined at 2.7 resolution from a previously reported starting model at 3 resolution based on asolvent flattened map and the revised primary structure consisting of 247 amlno-acids.The finalR-factor is 19.2% with the root mean-square deviations of 0.018 from ideal bond lengths andof 2.2° from ideal bond angles.Trichosanthin molecule is composed of two domains,the largedomain consisting of 181 amino-acld residues starting from N-terminus and the small domain con-sisting of the rest of the amino-acid residues.The molecule contains eight α-helices,five β-sheetsmade of sixteen β-strands,and some reverse turns.It is noteworthy that some of the α-helicesand β-sheets show irregular hydrogen bonding patterns.Six of the thirteen residues absolutelyconserved in eleven ribosome-inactivating proteins are located in a cleft near the interface ofthe two domains and they are likely to be active sites.Three additional conservative residueslocated in the cleft region might make some functional contribution as well.  相似文献   

10.
11.
An X-ray diffraction study of a substituted vanadatrane-1-one (space groupPna21,R= 0.019 for 1394 reflections, the absolute structure was determined) showed that the geometry of its atrane framework is similar to that of the Si- and Ge-analogs. The bond lengths are: V=O, 1.614(2) Å; VN, 2.329(2) Å; V-O, 1.800–1.806(2) Å. The deviation of the V atom having distorted trigonal bipyramidal coordination from the equatorial plane of the O atoms is 0.35 Å, the 0=VN bond angle is 179.4(1)°.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1477–1479, August, 1993.  相似文献   

12.
Slow evaporation in air of a lanthanum nitrate solution containing macrocyclic cavitand cucurbit[6]uril yields a complex of the composition of [La(H2O)6(X@C36H36N24O12)(NO3)](NO3)2· 6.96H2O (X = 0.5C5H5N + 0.5H2O). The complex is structurally characterized using single crystal X-ray diffraction. Lanthanum atoms are coordinated with oxygen atoms of carbonyl groups of cucurbit[6]uril portals. The compound crystallizes in the orthorhombic crystal system, space group Pnn2, unit cell parameters (150 K): a = 11.997(2) Å, b = 17.093(3) Å, c = 14.133(3) Å, V = 2899.3(10) Å3, Z = 2. Lanthanum atoms are disordered, alternative positions being related by the two-fold axis. The complex has an island structure. A pyridine molecule occupies an internal cavity of one half of cucurbit[6]uril molecules, while a water molecule occupies the other.  相似文献   

13.
Redetermination of the crystal structure of poly(p-benzamide) was made by using newly collected intensity data. The molecular conformation is TCTC, where the internal rotation angles about the N? C bond of the amide group and about the virtual bond of N-phenyl-C are T (trans) and C (cis) conformations, respectively. Two molecular chains pass through a rectangular unit cell with dimension, a = 7.75 Å, b = 5.30 Å, c (fiber axis) = 12.87 Å, and the space group, P212121-D. The reflection observed at the spacing of 010 may be attributed to the reflection due to another crystal polymorph or the diffuse scattering due to disorder. © 1993 John Wiley & Sons, Inc.  相似文献   

14.
Robert Bau  Irina Tsyba 《Tetrahedron》1999,55(52):2871-14846
Amikacin is one of the important aminoglycoside antibiotics used against gram-negative bacteria. Here we report the crystal structure of amikacin that has been crystallized by vapor diffusion against polyethylene glycol. The molecule exists in a long, extended conformation, with all three six-membered rings in chair conformations and connected together by -glycosidic linkages. The orientation between the A, B and C rings of the molecule is maintained by intramolecular hydrogen bonds involving the O5 hydroxyl group and the amide NH group.  相似文献   

15.
The crystal structure of acrylamide is re-determined by single crystal X-ray diffraction (133(1) K, BRUKER SMART 1000 CCD, a = 8.228(1) Å, b = 5.759(1) Å, c = 9.760(1) Å, β = 120.04(1)°, V = 400.3(1) Å,3, space group P21/c, Z = 4, R = 0.0543 for 867 reflections). In the structure strong hydrogen bonds N-H...O join the molecules of C3H5NO into bi-molecular layers that make C...C molecular contacts. It is demonstrated that the process of solid phase polymerization of acrylamide should proceed through the cleavage of double bonds C(1)=C(2) in the monomers and formation of bonds C(1)-C(1) and C(2)-C(2) between the closest carbon atoms of different layers.  相似文献   

16.
在甲醇和DMF溶剂里,以Schiff碱水杨醛缩氨基硫脲(简写为HL)和六水二氯化钴合成了配合物[CoHL2].H2O.DMF.在配合物[CoHL2]中,钴(Ⅱ)原子具有扭曲的N2O2S2八面体配位构型,晶体通过分子间氢键作用形成二维的无限网状结构.红外光谱表明,配体在形成配合物后,νS=O,νC=O和νC=N红移.荧光光谱表明,配合物金属对配体n-π*激发引起的荧光发射峰有较大的影响.  相似文献   

17.
The crystal structure of a 2: 1 inclusion complex of gossypol withm-xylene has been determined by X-ray structure analysis. The crystals of C30H30O8·0.5C8 H10 are triclinic, space groupPl,a = 8.478(1),b = 14.087(2),c = 14.411(2) Å, = 115,39(1), = 75.11(1), = 86.80(1)°,V = 1475.2(4) Å3,Z = 2,D x = 1.29 g cm–3,T = 295 K, (CuK ) = 7.01 cm–1. The structure has been solved by direct methods and refined to the finalR value of 0.079 for 3910 observed reflections. The gossypol molecules are linked by intermolecular hydrogen bonds and form bimolecular layers parallel to the ab plane. Disorderedm-xylene molecules occupy cavities between these layers. All polar groups of the gossypol molecule are packed in the interior of the bilayer while non-polar groups are directed outwards. An analysis of the crystal packing of other inclusion complexes of gossypol shows that such bilayers are formed in four complexes and three of those structures are generically related to each other.Deceased.  相似文献   

18.
The crystal structure of [Eu(TTA)2(NO3)(TPPO)2] (I) (TTA = thenoyltrifluoroacetone, TPPO = triphenylphosphine oxide) possessing intense triboluminescence was established by X-ray crystallography. The crystals are triclinic, noncentrocymmetrical: a = 11.047(3) Å, b = 11.794(3) Å, c = 12.537(3) Å; α = 102.635 (4)°, β = 102.088(4)°,γ = 117.765(3)°; space group P1, Z = 1. The central Eu(III) atom coordinates two oxygen atoms of two TPPO molecules at distances of 2.271 Å and 2.282 Å, two oxygen atoms of the nitrate group at distances of 2.478 Å and 2.481 Å, four oxygen atoms of two TTA ions at distances of 2.365 Å, 2.381 Å, and 2.363 Å, 2.371 Å (coordination number is 8). The coordination polyhedron of the Eu(III) atom is a distorted dodecahedron. Possible reasons for spectral differences in the Stark structure of photo-and triboluminescence of I are discussed.  相似文献   

19.
20.
The [nBu3Sn(N-phthaloylglycinate)(OH2)] compound has been prepared and characterized. The crystal structure reveals the tin atom, in each of the two molecules comprising the asymmetric unit, to exist in a distorted trigonal bipyramidal geometry in which the trigonal plane is defined by the three organic substituents and the axial sites are occupied by an oxygen atom derived from a monodentate carboxylate ligand and a coordinated water molecule. The [nBu3Sn(N-phthaloylglycinate)(OH2)] compound and three other triorganotin derivatives of N-phthaloyl-protected amino acids display marked toxicity against several economically important plant pathogenic fungi.  相似文献   

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