共查询到20条相似文献,搜索用时 109 毫秒
1.
R. Malathi S. S. Rajan Geetha Gopalakrishnan G. Suresh 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):o681-o682
The title compound, methyl (2aS,3R,5R,5aS,6S,6aS,8R,9aS,10aR,10bR,10cS)‐8‐(3‐furyl)‐2a,4,5,5a,6,6a,8,9,9a,10a,10b,10c‐dodecahydro‐3‐hydroxy‐2a,5a,6a,7‐tetramethyl‐5‐(3‐methylbut‐2‐enoyloxy)‐2H,3H‐cyclopenta[4′,5′]furo[2′,3′:6,5]benzo[cd]isobenzofuran‐6‐acetate, C32H42O8, was isolated from uncrushed green leaves of Azadirachta indica A. Juss (neem) and has been found to possess antifeedant activity against Spodptera litura. The conformations of the functional groups are similar to those of 3‐desacetylsalannin, which was isolated from neem kernels. The molecules are linked into chains by intermolecular O—H?O hydrogen bonds. 相似文献
2.
Libin Gao 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(6):634-637
The title compound, C58H64S8, has been prepared by Pd‐catalysed direct C—H arylation of tetrathienonaphthalene (TTN) with 5‐hexyl‐2‐iodothiophene and recrystallized by slow evaporation from dichloromethane. The crystal structure shows a completely planar geometry of the TTN core, crystallizing in the monoclinic space group P21/c. The structure consists of slipped π‐stacks and the interfacial distance between the mean planes of the TTN cores is 3.456 (5) Å, which is slightly larger than that of the comparable derivative of tetrathienoanthracene (TTA) with 2‐hexylthiophene groups. The packing in the two structures is greatly influenced by both the aromatic core of the structure and the alkyl side chains. 相似文献
3.
A series of novel 3′‐(alkyl(hydroxy)amino)‐2′‐fluoronucleoside analogs were prepared via conjugate addition of N‐methylhydroxylamine to various 2‐fluorobutenolides. The adducts 13a and 16 were obtained as single isomers under absolute control of stereochemistry. The crucial N‐demethylation of 23 – 25 was readily achieved by means of DDQ oxidation, followed by nitrone/oxime exchange reaction. By this procedure, a variety of alkyl groups could be efficiently introduced at the 3′‐N‐atom of the nucleoside analogs, some of which might display potentially interesting anti‐HIV properties. 相似文献
4.
Three title compounds 4a—4c have been synthesized by the cyclodehydration of 1’-benzylidine-4’-(3β-substituted-5α-cholestane-6-yl)thiosemicarbazones 2a—2c with thioglycolic acid followed by the treatment with cold conc. H2SO4 in dioxane. The compounds 2a—2c were prepared by condensation of 3β-substituted-5α-cholestan- 6-one-thiosemicarbazones 1a—1c with benzaldehyde. These thiosemicarbazones 1a—1c were obtained by the reaction of corresponding 3β-substituted-5α-cholestan-6-ones with thiosemicarbazide in the presence of few drops of conc. HCl in methanol. The structures of the products have been established on the basis of their elemental, analytical and spectral data. 相似文献
5.
Aleksandar Vinjevac Biserka Koji‐Prodi Marijana Vinkovi Kata Mlinari‐Majerski 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o314-o316
The conformational features of the title compound, C28H44S6, are compared with previously reported analogous macrocycles. The type of substituent affects considerably the conformation of the macrocycle. A 1H NMR titration of the title compound with AgBF4 indicated the formation of the 1:1 complex, which was not crystallized. 相似文献
6.
Min Jiang Jun Li Feng‐Xing Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):m501-m503
The title compound, [Mn(C14H8O4)(C12H12N2)]n, with a novel three‐dimensional framework, has been prepared by a hydrothermal reaction at 433 K. Each Mn atom lies on a twofold axis in a slightly distorted octahedral geometry, coordinated by two N atoms from two benzidine ligands and four O atoms from three symmetry‐related biphenyl‐2,2′‐dicarboxylate (bpdc) ligands. The benzidine ligands lie about inversion centres and the bpdc ligands about twofold axes. Each bpdc ligand is bonded to three Mn ions to form a continuous chain of metal ions. The bpdc ligands are accommodated in a series of distorted holes resembling hexagonal prisms. 相似文献
7.
amil Ik Sema
ztürk Hoong‐Kun Fun Erbil Agar Selami amaz 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):95-96
The structure of the title compound, 4‐allyl‐2‐methoxy‐6‐[(4‐nitrophenyl)diazenyl]phenyl benzoate, C23H19N3O5, displays the characteristic features of azobenzene derivatives. The azobenzene moiety of the molecule has a trans configuration and in this moiety, average C—N and N=N bond lengths are 1.441 (3) and 1.241 (3) Å, respectively. 相似文献
8.
Mireille Perec Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):m140-m144
The title copper complex, [Cu(H2P2O7)(C15H11N3)]2·4.5H2O, consists of two very similar independent Cu(Tpy)H2P2O7 monomeric units (Tpy is 2,2′:6′,2′′‐terpyridine) plus four and a half water molecules of hydration, some of which are disordered. Tpy units bind through the usual triple bite via their N atoms, and the H2P2O72− anions coordinate through two O atoms from two different phosphate units. Each independent CuN3O2 chromophore can be described as a slightly deformed square pyramid, with one of them having a sixth, semicoordinated, O atom from a centrosymmetrically related CuN3O2 unit in a weakly bound second apical position suggesting an octahedral environment for the cation and weak dimerization of the molecule. The two independent complex molecules are connected via two strong O—H...O interactions between the phosphate groups to form hydrogen‐bonded dinuclear units, further linked into [111] columns, resulting in a very complex three‐dimensional supramolecular structure through a variety of classical and nonclassical hydrogen bonds, as well as π–π interactions. 相似文献
9.
Pawe Wagner David L. Officer Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o400-o404
In the crystal structures of four thiophene derivatives, (E)‐3′‐[2‐(anthracen‐9‐yl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C28H18S3, (E)‐3′‐[2‐(1‐pyrenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C30H18S3, (E)‐3′‐[2‐(3,4‐dimethoxyphenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C22H18O2S3, and (E,E)‐1,4‐bis[2‐(2,2′:5′,2′′‐terthiophen‐3′‐yl)ethenyl]‐2,5‐dimethoxybenzene, C36H26O2S6, at least one of the terminal thiophene rings is disordered and the disorder is of the flip type. The terthiophene fragments are far from being coplanar, contrary to terthiophene itself. The central C—C=C—C fragments are almost planar but the bond lengths suggest slight delocalization within this fragment. The crystal packing is determined by van der Waals interactions and some weak, relatively short, C—H...S and C—H...π directional contacts. 相似文献
10.
Zhiqiang Liu Qi Fang Wentao Yu Gang Xue Duxia Cao Minhua Jiang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o445-o446
The title compound, 3‐[4‐(dimethylamino)phenyl]‐1‐(2‐hydroxyphenyl)prop‐2‐en‐1‐one, C17H17NO2, is a chalcone derivative substituted by 2′‐hydroxyl and 4′′‐dimethylamino groups. The crystal structure indicates that the aniline and hydroxyphenyl groups are nearly coplanar, with a dihedral angle of 10.32 (16)° between their phenyl rings. The molecular planarity of this substituted chalcone is strongly affected by the 2′‐hydroxyl group. 相似文献
11.
Wei Sun Yan‐Tuan Li Zhi‐Yong Wu Ning‐Yu Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m111-m113
In the crystal structure of the title complex, [Ni2(C10H20N4O2)(C12H12N2)2](ClO4)2 or [Ni(dmaeoxd)Ni(dmbp)2](ClO4)2 {H2dmaeoxd is N,N′‐bis[2‐(dimethylamino)ethyl]oxamide and dmbp is 4,4′‐dimethyl‐2,2′‐bipyridine}, the deprotonated dmaeoxd2− ligand is in a cis conformation and bridges two NiII atoms, one of which is located in a slightly distorted square‐planar environment, while the other is in an irregular octahedral environment. The cation is located on a twofold symmetry axis running through both Ni atoms. The dmaeoxd2− ligands interact with each other via C—H⋯O hydrogen bonds and π–π interactions, which results in an extended chain along the c axis. 相似文献
12.
Katarzyna
lepokura Tadeusz Lis Magorzata Bogucka Joanna Lutomska Adam Kraszewski Krzysztof Sierosawski 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o405-o409
The crystal structures of triethylammonium adenosine cyclic 2′,3′‐phosphate {systematic name: triethylammonium 4‐(6‐aminopurin‐9‐yl)‐6‐hydroxymethyl‐2‐oxido‐2‐oxoperhydrofurano[3,4‐c][1,3,2]dioxaphosphole}, Et3NH(2′,3′‐cAMP) or C6H16N+·C10H11N5O6P−, (I), and guanosine cyclic 2′,3′‐phosphate monohydrate {systematic name: triethylammonium 6‐hydroxymethyl‐2‐oxido‐2‐oxo‐4‐(6‐oxo‐1,6‐dihydropurin‐9‐yl)perhydrofurano[3,4‐c][1,3,2]dioxaphosphole monohydrate}, [Et3NH(2′,3′‐cGMP)]·H2O or C6H16N+·C10H11N5O7P−·H2O, (II), reveal different nucleobase orientations, viz. anti in (I) and syn in (II). These are stabilized by different inter‐ and intramolecular hydrogen bonds. The structures also exhibit different ribose ring puckering [4E in (I) and 3T2 in (II)] and slightly different 1,3,2‐dioxaphospholane ring conformations, viz. envelope in (I) and puckered in (II). Infinite ribbons of 2′,3′‐cAMP− and helical chains of 2′,3′‐cGMP− ions, both formed by O—H⋯O, N—H⋯X and C—H⋯X (X = O or N) hydrogen‐bond contacts, characterize (I) and (II), respectively. 相似文献
13.
Qi‐Wei Zhang Yi‐Hang Wen Yun‐Long Feng 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m255-m257
The title compound, [Zn2(C5H6O4)2(C13H14N2)]n or [Zn2(glu)2(bpp)]n, is a novel zinc polymer based on mixed flexible glutarate (glu) and 1,3‐di‐4‐pyridylpropane (bpp) ligands. The ZnII center has a distorted tetrahedral geometry and the central atom of the bpp ligand is located at a special site with a C2 axis passing through it. A layer is formed by Zn–glu bonding. Such layers are pillared by bpp ligands, forming a three‐dimensional framework with large channels. The inverted interpenetration of two three‐dimensional frameworks completes the molecular structure. 相似文献
14.
Reza‐Ali Fallahpour Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(5):o283-o285
In the nearly planar title compound, C15H10IN3, the three pyridine rings exhibit transoid conformations about the interannular C—C bonds. Very weak C—H...N and C—H...I interactions link the molecules into ribbons. Significant π–π stacking between molecules from different ribbons completes a three‐dimensional framework of intermolecular interactions. Four different packing motifs are observed among the known structures of simple 4′‐substituted terpyridines. 相似文献
15.
Rüdiger W. Seidel Iris M. Oppel 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(6):m199-m201
The title compound, [Pd2(C4H13N3)2(C14H16N2)](NO3)4, comprises discrete tetracationic dumbbell‐type dinuclear complex molecules and noncoordinating nitrate anions. Two Pd(dien)2+ moieties (dien is diethylenetriamine) are joined by the rigid linear exo‐bidentate bridging 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine ligand to form the dinuclear complex, which lies across a centre of inversion in the space group P21/n, so that the rings in the 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine bridging ligand are parallel. In the crystal, the primary and secondary amino groups of the dien ligand act as hydrogen‐bond donors towards the nitrate anions to form a three‐dimensional hydrogen‐bond network. 相似文献
16.
Hans‐Ruedi Mürner Rosario Scopelliti Jean‐Claude G. Bünzli 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):m434-m435
In the title compound, [TbCl(C27H35N3)2(H2O)](ClO4)2·2C2H6O, the TbIII ion has a coordination number of eight, composed of two tridentate substituted‐terpyridine ligands, a water molecule and a bound Cl? anion. The first coordination shell can be described as a distorted bicapped trigonal prism. The dihedral angles between pyridine rings belonging to the same tpy ligand range from 5.2 (5) to 16.8 (5)°. 相似文献
17.
Kanidtha Hansongnern Uraiwan Saeteaw Jack Cheng Fen‐Ling Liao Tian‐Huey Lu 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):895-896
The Ru—N bond distances in the title complex, [Ru(NO2)(C11H9N3)(C15H11N3)]BF4 or [Ru(NO2)(tpy)(azpy)]BF4, [tpy is 2,2′:6′,2′′‐terpyridine and azpy is 2‐(phenylazo)pyridine], are Ru—Npy 2.063 (4), Ru—Nazo 2.036 (4), Ru—Nnitro 2.066 (3) Å, and Ru—Ntpy 2.082 (4), 1.982 (3) and 2.074 (4) Å. The azo N atom is trans to the nitro group. The azo N=N bond length is 1.265 (5) Å, which is the shortest found in such complexes to date. This indicates a multiple bond between Ru and the N atom of the nitro group, and π‐backbonding [dπ(Ru) π*(azo)] is decreased. 相似文献
18.
Ute Baumeister Helmut Hartung Roland Spitzner Michael Felicetti Werner Schroth 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):830-831
The (3R*,3′R*) configuration of the title compound, C18H16N2S2, (I), has been unambiguously elucidated by X‐ray analysis. Molecules of (I) have C2 symmetry to a good approximation and a strongly folded shape. The interplanar angle between the two halves of a molecule is 67.11 (6)°. 相似文献
19.
20.
Ana María García Jorge Manzur Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):m335-m337
The title compund, [Cu2(OH)2(C22H25N3)2](ClO4)2, is a copper(II) dimer, with two [CuL]2+ units [L is bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine] bridged by hydroxide groups to define the {[CuL](μ‐OH)2[CuL]}2+ cation. Charge balance is provided by perchlorate counter‐anions. The cation has a crystallographic inversion centre halfway between the CuII ions, which are separated by 3.0161 (8) Å. The central core of the cation is an almost regular Cu2O2 parallelogram of sides 1.931 (2) and 1.935 (2) Å, with a Cu—O—Cu angle of 102.55 (11)°. The coordination geometry around each CuII centre can be best described as a square‐based pyramid, with three N atoms from L ligands and two hydroxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide–perchlorate O—H...O interactions. 相似文献