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1.
Mason A. Wolak Robert C. Finn Randy S. Rarig Craig J. Thomas Robert P. Hammond Robert R. Birge Jon Zubieta Watson J. Lees 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o389-o393
Fluorinated indolylfulgides are a class of photochromic organic compounds that meet many of the requirements for use as optical memory media and optical switches. The X‐ray crystal structures of a series of five photochromic fluorinated indolylfulgides have been determined, namely (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,2‐trifluoroethylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (trifluoromethylisopropylideneindolylfulgide), C19H16F3NO3, (I), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,3‐pentafluoropropylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (pentafluoroethylisopropylideneindolylfulgide), C20H16F5NO3, (II), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐heptafluorobutylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (heptafluoropropylisopropylideneindolylfulgide), C21H16F7NO3, (III), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,2‐trifluoroethylidene]‐4‐(tricyclo[3.3.1.13,7]decylidene)dihydrofuran‐2,5‐dione (trifluoromethyladamantylideneindolylfulgide), C26H24F3NO3, (IV), and (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐heptafluorobutylidene]‐4‐(tricyclo[3.3.1.13,7]decylidene)dihydrofuran‐2,5‐dione (heptafluoropropyladamantylideneindolylfulgide), C28H24F7NO3, (V). The photochromic property of fulgides is based on the photochemically allowed electrocyclic ring closure of a hexatriene system to form a cyclohexadiene. For each fulgide examined, the bond lengths within the hexatriene system alternate between short and long, as expected. Comparing the structures of the five fulgides with each other demonstrates no significant difference in bond lengths, bond angles or dihedral angles within the hexatriene systems. The distance between the bond‐forming C atoms at each end of the hexatriene system does vary. Correlations of structural properties with optical properties are addressed. 相似文献
2.
Pongchan Thinapong Orapin Rangsiman Patoomratana Tuchinda Bamroong Munyoo Manat Pohmakotr Vichai Reutrakul 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):e309-e310
A new azaanthracene alkaloid, namely 9,10‐dimethoxy‐4‐methyl‐1,2‐dihydro‐1‐azaanthracen‐2‐one (kalasinamide), C16H15NO3, has been isolated from the stems of Polyalthia suberosa collected in the northeastern part of Thailand. Each of the aromatic rings in the molecule is planar within 0.021 (2) Å. Molecules are linked to form centrosymmetric dimers by N—H?O hydrogen bonds [N?O 2.941 (4) Å]. 相似文献
3.
John Reglinski Michelle K. Taylor Alan R. Kennedy 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o169-o172
We have isolated and crystallographically characterized the three homologous compounds N,N′‐bis(2‐methoxybenzylidene)ethane‐1,2‐diamine (MeSalen), C18H20N2O2, N,N′‐bis(2‐methoxybenzylidene)propane‐1,3‐diamine (MeSalpr), C19H22N2O2, and N,N′‐bis(2‐methoxybenzylidene)butane‐1,4‐diamine (MeSalbu), C20H24N2O2. In contrast with MeSalpr, the molecules of MeSalen and MeSalbu, which have an even number of methylene units, have crystallographic symmetry. Comparing these methoxy‐substituted species with their hydroxy equivalents shows that the aryl rings rotate upon removal of the O—H⋯N hydrogen bonds. The packing of MeSalen and MeSalpr is controlled by C—H⋯π interactions, whereas that of MeSalbu has only van der Waals contacts. 相似文献
4.
Hassan Y. Elnagar Paul F. Ranken Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):905-906
The title spirodiphosphonate, 3,9‐dimethyl‐2,4,8,10‐tetraoxa‐3λ5,9λ5‐diphosphaspiro[5.5]undecane‐3,9‐dione, C7H14O6P2, a polymer additive, has crystallographic symmetry 2. At 100 K, its six‐membered rings have chair conformations, with endocyclic torsion‐angle magnitudes in the range 51.87 (8)–58.93 (9)°. The P=O distance is 1.4749 (8) Å, while the P—C(methyl) distance is 1.7691 (12) Å. 相似文献
5.
Elena Buuel Carlos Cativiela María D. Díaz‐de‐Villegas Jos A. Glvez 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):587-591
The structures of two conformationally restricted 4,5‐dihydroxynorvaline analogues with a norbornane skeleton, namely methyl (1S,2S,3R,4R)‐2‐benzamido‐3‐(1,2‐dihydroxyethyl)bicyclo[2.2.1]heptane‐2‐carboxylate, C18H23NO5, and methyl (1R,2S,3R,4S)‐2‐benzamido‐3‐(1,2‐dihydroxyethyl)bicyclo[2.2.1]heptane‐2‐carboxylate, C18H23NO5, exhibit a conformation in the helical region of the ?,ψ map but their handedness is opposite. In both cases, the torsion angles (χ1,1) giving the relative orientation of the 1,2‐dihydroxyethyl group of the amino acid side chain and the benzamide group of the peptide chain indicate that these groups adopt a nearly eclipsed conformation. Both compounds show a complex hydrogen‐bonding pattern. 相似文献
6.
Gopeswar Chaudhuri Madeleine Helliwell Nitya G. Kundu 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):740-741
In the title compound, C22H17Cl2NO3S, the molecule is a substituted 3,4‐dihydro‐2H‐1,4‐benzoxazine compound which has three phenyl rings which are essentially planar. The 3,4‐dihydro‐2H‐oxazine part of the molecule is fused to the benzo ring and has a half‐boat conformation; the dihedral angle between the planar part of the oxazine ring and the benzo ring is 10.2 (2)°. The (3‐chlorophenyl)methylidene substituent has a Z configuration in relation to the ring N atom of the oxazine moiety. Interestingly, the p‐toluenesulfonyl (p‐tosyl) substituent on the ring N atom protrudes away from the 3‐chlorophenyl substituent thus avoiding any steric interaction. 相似文献
7.
John Nicolson Low Justo Cobo Manuel Nogueras Adolfo Snchez Braulio Insuasty Harlen Torres 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o39-o41
2,2‐Dimethyl‐5‐[3‐(4‐methylphenyl)‐2‐propenylidene]‐1,3‐dioxane‐4,6‐dione, C16H16O4, crystallizes in the triclinic space group , with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chlorophenyl)‐2‐propenylidene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione, C15H13ClO4, also crystallizes in the triclinic space group , with one molecule in the asymmetric unit. Centrosymmetrically related molecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis. 相似文献
8.
Ivan Leban Lovro Seli
Toma Mesar Anton opar Tom olmajer 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):o367-o369
The molecular structure of the title tricyclic compound, C17H21NO4, which is the immediate precursor of a potent synthetic inhibitor {Lek157: sodium (8S,9R)‐10‐[(E)‐ethylidene]‐4‐methoxy‐11‐oxo‐1‐azatricyclo[7.2.0.03,8]undec‐2‐ene‐2‐carboxylate} with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclohexyl ring and the carbonyl group of the β‐lactam ring, which takes part in the formation of the initial tetrahedral acyl–enzyme complex. In this hydrophobic molecule, the overall geometry is influenced by C—H?O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) Å, with corresponding normalized H?O distances of 2.30 and 2.46 Å], whereas the molecules are interconnected through intermolecular C—H?O hydrogen bonds [3.335 (4)–3.575 (5) Å]. 相似文献
9.
Jarno Kansikas Kaija Sipil 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o16-o18
The first butterfly‐shaped anthracene dimer including S atoms,8,9‐dihydro‐3a,8[1′,2′]:9,13b[1′′,2′′]dibenzenodibenzo[3,4:7,8]cycloocta[1,2‐d]‐1,3‐dithiole, C29H20S2, contains an exceptionally long Csp3—Csp3 bond of 1.672 (2) Å in the fused 1,3‐dithiole ring. The length of the other bond bridging the anthracene moieties is 1.604 (3) Å. 相似文献
10.
9,10‐Diphenyl‐9,10‐epidioxyanthracene and 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol
Anwar Usman Hoong‐Kun Fun Yun Li Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o308-o310
9,10‐Diphenyl‐9,10‐epidioxyanthracene, C26H18O2, (I), was accidentally used in a photooxygenation reaction that produced 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol, C22H20O3, (II). In both compounds, the phenyl rings are approximately orthogonal to the anthracene moiety. The conformation of the anthracene moiety differs as a result of substitution. Intramolecular C—H⃛O interactions in (I) form two approximately planar S(5) rings in each of the two crystallographically independent molecules. The packing of (I) and (II) consists of molecular dimers stabilized by C—H⃛O interactions and of molecular chains stabilized by O—H⃛O interactions, respectively. 相似文献
11.
Masaaki Tomura Yoshiro Yamashita 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):619-620
The title compound, 6‐(1,3‐benzodithiol‐2‐ylidene)‐5,7‐dimethyl‐1,2‐diphenylpentacyclo[5.4.0.02,5.03,11.04,8]undecane, C32H28S2, with a C1‐homobasketane framework, crystallizes in the P space group with one molecule in the asymmetric unit. The two cyclobutane rings in the cage are in a puckered conformation. Due to the enhanced through‐bond interaction of the phenyl π systems involving a strained σ bond, the (Ph—)C—C(—Ph) bond length is significantly extended, to 1.610 (3) Å. 相似文献
12.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e149-e150
In the three title crystal structures 4‐(dimethylamino)pyridinium 2,4‐dinitrobenzoate, (I), 4‐(dimethylamino)pyridinium 3,4‐dinitrobenzoate, (II), and 4‐(dimethylamino)pyridinium 3,5‐dinitrobenzoate, (III), all C7H11N2+·C7H3N2O6?, the ions are connected by an N—H?O hydrogen bond. Dihedral angles between the pyridine and phenyl rings are 69.9 (1), 26.7 (1) and 56.2 (1)° in (I), (II) and (III), respectively. Donor–acceptor π–π stacking is observed in (II) and (III), but not in (I). 相似文献
13.
J. Zukerman‐Schpector I. Caracelli Mauricio Vega Mauricio Gomes Constantino Adilson Beatriz Gil Valdo Da Silva 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):646-648
In both 9,10‐dimethoxy‐11‐oxatricyclo[6.2.1.02,7]undeca‐4,9‐diene‐3,6‐diol, C12H16O5, (I), and 5,6‐dimethoxy‐3,7‐dioxatetracyclo[6.4.0.02,6.04,12]dodec‐9‐en‐11‐ol, C12H16O5, (II), the hetero‐oxygen‐containing five‐membered rings have an envelope conformation. The six‐membered rings are in a boat conformation in compound (I), and in (II), one is in a half‐boat and the other is in a slightly distorted boat conformation. The molecules in both compounds interact through classical hydrogen bonds and C—H?O contacts. 相似文献
14.
Jaromír Marek Dagmar Hulov Jií Dostl Radek Marek 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o583-o585
The title compound [systematic name: 9,10‐dimethoxy‐2,3‐methylenedioxy‐5,6‐dihydrodibenzo[a,g]quinolizinium formate–succinic acid (1/1)], C20H18NO4+·CHO2−·C4H6O4, contains centrosymmetric pairs of almost planar berberine cations, and hydrogen‐bonded (C4H6O4⋯HCOO−)2 rings of succinic acid with formate anions, bonded by O—H⋯O hydrogen bonds with O⋯O distances of 2.4886 (15) and 2.5652 (16) Å. Pairs of cations and molecules of succinic acid are connected by non‐conventional weak C—H⋯O hydrogen bonds, with C⋯O distances of 3.082 (2) and 3.178 (2) Å. 相似文献
15.
Elizabeth J. MacLean Simon J. Teat Dorcas M. M. Farrell George Ferguson Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o470-o473
The title compound, meso‐5,7,7,12,14,14‐hexamethyl‐4,11‐diaza‐1,8‐diazoniacyclotetradecane bis(3‐carboxy‐5‐nitrobenzoate), C16H38N42+·2C8H4NO6?, is a salt in which the cation is present as two configurational isomers, disordered across a common centre of inversion in P, with occupancies of 0.847 (3) and 0.153 (3). The anions are linked into chains by a single O—H?O hydrogen bond [H?O 1.71 Å, O?O 2.5063 (15) Å and O—H?O 156°] and the cations link these anion chains into sheets by means of a range of N—H?O hydrogen bonds [H?O 1.81–2.53 Å, N?O 2.718 (5)–3.3554 (19) Å and N—H?O 146–171°]. 相似文献
16.
Kamlakar Avasthi Ashish Tewari Diwan S. Rawat Ashoke Sharon Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o494-o495
In the crystal structure of 1,1′‐(1,3‐propanediyl)bis(5‐benzyl‐6‐methylsulfanyl‐4,5‐dihydro‐1H‐pyrazolo[3,4‐d]pyrimidin‐4‐one), C29H28N8O2S2, the pairs of pyrazolo[3,4‐d]pyrimidine rings stack as a result of intramolecular π–π interactions between the heterocyclic rings. The folded molecules are further stacked in pairs, due to intermolecular aromatic π–π interactions and C—H?O hydrogen bonds. 相似文献
17.
Simon J. Garden Fernando R. da Cunha Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o12-o14
In 2‐hydroxy‐3‐iodo‐5‐nitrobenzaldehyde, C7H4INO4, the molecules are linked into sheets by a combination of C—H⋯O hydrogen bonds and two‐centre iodo–nitro interactions, and these sheets are linked by aromatic π–π stacking interactions. Molecules of 2,4‐diiodo‐6‐nitroanisole, C7H5I2NO3, are disordered, with the nitro group and one of the I substituents each occupying common sets of sites with 0.5 occupancy. The molecules are linked into isolated centrosymmetric dimeric units by a single iodo–nitro interaction. 相似文献
18.
Ponraj Prabakaran Jebamony Justin Robert Packianathan Thomas Muthiah Gabriele Bocelli Lara Righi 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):459-461
In the title cocrystal, trimethoprim maleate [2,4‐diamino‐5‐(3,4,5‐trimethoxybenzyl)pyrimidin‐1‐ium maleate], C14H19N4O3+·C4H3O4?, the trimethoprim molecule is protonated at N1. The carboxyl group of the maleate ion makes a specific double hydrogen bond of type N—H?O with the 2‐amino group and the protonated N1 atom of the trimethoprim cation which is similar to the carboxylate–trimethoprim cation interaction observed in the complex of dihydrofolate reductase with trimethoprim. The pyrimidine moieties of trimethoprim cations are centrosymmetrically paired through a pair of N—H?N hydrogen bonds involving the 4‐amino group and the pyridinium N3 atom of a symmetry‐related molecule. One of the O atoms at the maleate carboxylate group bridges the 2‐amino and 4‐amino groups on either side of the paired trimethoprim cations. The other O atom of the carboxylate group forms an intramolecular O—H?O hydrogen bond with the carboxyl group. These characteristic hydrogen bonds result in infinite two‐dimensional aggregation of rings into a supramolecular ladder, which is further crosslinked through weak C—H?O interactions with methoxy groups of neighbouring trimethoprim molecules to form a layered structure. 相似文献
19.
Sara K. Metcalf Elizabeth M. Holt 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1228-1231
Diethyl 4‐(2,5‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (I), diethyl 4‐(3,4‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (II), and diethyl 2,6‐dimethyl‐4‐(3,4,5‐trimethoxyphenyl)‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C22H29NO7, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐dihydropyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors. 相似文献
20.
Ramis Rao Subramanian Shanmuga S. Anandan Kuan Hiang Kwek Kum Sang Low S. Shanmuga Sundara Raj Hoong‐Kun Fun Ibrahim Abdul Razak John V. Hanna Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):e292-e294
The monoclinic cell of dicyclohexylammonium 2,4‐dichlorophenoxyacetate contains four C12H24N+·C5H8Cl2O3? ion pairs. The ammonium N atom is hydrogen bonded to the oxygen ends of two carboxyl groups to form a 12‐membered O—C—O?HNH?O—C—O?HNH ring. In (2,4‐dichlorophenoxylacetato)bis(triphenylphosphine)silver(I), [Ag(C8H5Cl2O3)(C18H15P)2], the carboxyl CO2 unit chelates to the Ag atom in an anisobidentate manner [Ag—O = 2.436 (2) and 2.517 (2) Å]; the Ag atom shows distorted tetrahedral geometry. 相似文献