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1.
Susan A. McWilliam Janet M. S. Skakle John N. Low James L. Wardell Simon J. Garden Angelo C. Pinto Jose C. Torres Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):942-945
In the triclinic polymorph of 2‐iodo‐4‐nitroaniline, C6H5IN2O2, space group P, the molecules are linked by paired N—H?O hydrogen bonds into C(8)[R(6)] chains of rings. These chains are linked into sheets by nitro?I interactions, and the sheets are pairwise linked by aromatic π–π‐stacking interactions. In the orthorhombic polymorph, space group Pbca, the molecules are linked by single N—H?O hydrogen bonds into spiral C(8) chains; the chains are linked by nitro?O interactions into sheets, each of which is linked to its two immediate neighbours by aromatic π–π‐stacking interactions, so producing a continuous three‐dimensional structure. 相似文献
2.
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
3.
Doyle Britton 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o510-o514
Two polymorphs of 3,5‐dichloro‐4‐cyanobenzoic acid, C8H3Cl2NO2, viz. triclinic and monoclinic, and its 0.25‐hydrate, C8H3Cl2NO2·0.25H2O, form crystals in which hydrogen bonding and Cl⋯N interactions appear to be equally important to the structures. In all three structures, there are hydrogen‐bonded (COOH) dimers of the well known cyclic type, but in the hydrate there are also dimers in which the two opposing COOH groups are separated by a water molecule. In the monoclinic polymorph and in the hydrate, the intermolecular interactions form two‐dimensional nets interwoven three at a time. For both the triclinic and monoclinic polymorphs, Z′= 2. 相似文献
4.
Jerzy Cieplik Janusz Pluta Tadeusz Lis Iwona Bryndal 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o259-o261
Two polymorphic forms of the title compound, C24H20Cl2N4, were obtained and characterized using X‐ray crystal structure analysis. Colourless crystals of polymorph (Ia) were obtained from the oily mother residue. Recrystallization of polymorph (Ia) from an acetone–methanol mixture resulted in pale‐yellow crystals of polymorph (Ib). The major feature distinguishing the two polymorphic forms is their interaction modes, and hence their packing arrangements. In the crystal structure of polymorph (Ia), there are N—H⋯N hydrogen bonds and also aromatic π–π stacking interactions between molecules. The molecules of polymorph (Ib) are linked by N—H⋯Cl hydrogen bonds only. 相似文献
5.
Katharine F. Bowes Christopher Glidewell John N. Low Manuel Melguizo Antonio Quesada 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o4-o8
Crystallization of 2‐amino‐4‐chloro‐6‐morpholinopyrimidine, C8H11ClN4O, (I), yields two polymorphs, both with space group P21/c, having Z′ = 1 (from diethyl ether solution) and Z′ = 2 (from dichloromethane solution), denoted (Ia) and (Ib), respectively. In polymorph (Ia), the molecules are linked by an N—H⋯O and an N—H⋯N hydrogen bond into sheets built from alternating R(8) and R(40) rings. In polymorph (Ib), one molecule acts as a triple acceptor of hydrogen bonds and the other acts as a single acceptor; one N—H⋯O and three N—H⋯N hydrogen bonds link the molecules in a complex chain containing two types of R(8) and one type of R(18) ring. 2‐Amino‐4‐chloro‐6‐piperidinopyrimidine, C9H13ClN4, (II), which is isomorphous with polymorph (Ib), also has Z′ = 2 in P21/c, and the molecules are linked by three N—H⋯N hydrogen bonds into a centrosymmetric four‐molecule aggregate containing three R(8) rings. 相似文献
6.
Jerzy Ossowski Piotr Ku Christian Nther Peter G. Jones 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o369-o371
The title compound, C24H24N2O2, crystallizes as a triclinic polymorph from dimethylformamide and a monoclinic polymorph from ethanol. In both forms, the molecule displays crystallographic inversion symmetry, and the packing involves translationally related `ladders' of molecules connected by N—H⋯O=C hydrogen bonds. Differences between the structures can be rationalized in terms of weak C—H⋯O contacts. Powder and differential scanning calorimetry investigations of new samples gave no evidence for the triclinic form, and it seems to represent a disappearing polymorph. 相似文献
7.
Rodrigo S. Corrêa Sarita A. Santana Rogrio Salloum Rosalice M. Silva Antnio C. Doriguetto 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):o115-o117
A planar conformation of 1,3‐thiazolidine‐2‐thione (TZDTH), C3H5NS2, was crystallized for the first time. The new triclinic polymorph (P) obtained was compared in terms of its intra‐ and intermolecular geometry with three previous reports of a monoclinic polymorph (P21/n). The packing is based on centrosymmetric dimers of TZDTH, linked by N—H⋯S hydrogen bonds. 相似文献
8.
Christopher Glidewell John N. Low Manuel Melguizo Antonio Quesada 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o14-o18
In 2‐amino‐4,6‐dimethoxy‐5‐nitropyrimidine, C6H8N4O4, the molecules are linked by one N—H⋯N and one N—H⋯O hydrogen bond to form sheets built from alternating R(8) and R(32) rings. In isomeric 4‐amino‐2,6‐dimethoxy‐5‐nitropyrimidine, C6H8N4O4, which crystallizes with Z′ = 2 in P, the two independent molecules are linked into a dimer by two independent N—H⋯N hydrogen bonds. These dimers are linked into sheets by a combination of two‐centre C—H⋯O and three‐centre C—H⋯(O)2 hydrogen bonds, and the sheets are further linked by two independent aromatic π–π‐stacking interactions to form a three‐dimensional structure. 相似文献
9.
Alexander B. Zolotoy Mark Botoshansky Menahem Kaftory John R. Scheffer Jie Yang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o220-o222
The title compound, C17H14N2S, crystallizes in a triclinic unit cell, with two crystallographically independent molecules in the asymmetric unit. The two independent molecules pack in the same sense and form segregated layers along the c axis. The crystal is light‐stable and no dimers are formed under irradiation. The intermolecular distances between the potential reactive centers (the C‐3 and C‐5 ring positions) are 4.093 (4) and 5.643 (4) Å for molecule A, and 4.081 (4) and 5.614 (4) Å for molecule B. 相似文献
10.
J. R. Anacona Jofre Gmez Daniel Loroo 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o277-o280
Colourless crystals of the title compound, bis(2‐bromophenyl) disulfide, C12H8Br2S2, are obtained from the reaction of 2‐bromophenylmercaptan with metallic sodium and either zinc chloride or cadmium chloride in methanol. In the presence of ZnII ions, the crystals are orthorhombic (space group Pbca, with Z′ = 1); with CdII ions present, the product is triclinic (space group , with Z′ = 4). Both polymorphs exhibit significant intramolecular C—H⋯S hydrogen bonds. In the orthorhombic form, molecules are linked by intermolecular C—H⋯Br hydrogen bonds, while in the triclinic form, molecules exhibit Br⋯Br contacts. 相似文献
11.
12.
Hamid Reza Nasiri M. Gregor Madej C. Roy D. Lancaster Harald Schwalbe Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o671-o673
The title compound, C14H12O4, forms crystals which appear monoclinic but are actually twinned triclinic. The asymmetric unit consists of two similar molecules, which differ only in the conformation of the 3‐oxobutyl side chain. The molecular conformation is characterized by an intramolecular O—H⋯O hydrogen bond between the hydroxy group and the adjacent carbonyl O atom. The crystal structure is stabilized by O—H⋯O hydrogen bonds connecting the molecules into zigzag chains running along the b axis. 相似文献
13.
Onur ahin Orhan Büyükgüngr Selami amaz Nurhan Gümrüküolu Cihan Kantar 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):o643-o646
The title compounds, C10H12N4, (I), and C9H10N4, (II), have been synthesized and characterized both spectroscopically and structurally. The dihedral angles between the triazole and benzene ring planes are 26.59 (9) and 42.34 (2)°, respectively. In (I), molecules are linked principally by N—H⋯N hydrogen bonds involving the amino NH2 group and a triazole N atom, forming R44(20) and R24(10) rings which link to give a three‐dimensional network of molecules. The hydrogen bonding is supported by two different C—H⋯π interactions from the tolyl ring to either a triazole ring or a tolyl ring in neighboring molecules. In (II), intermolecular hydrogen bonds and C—H⋯π interactions produce R34(15) and R44(21) rings. 相似文献
14.
Doyle Britton Frank B. Mallory Clelia W. Mallory 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o235-o238
The molecular structures of 4,7‐dichlorobenzo[c]furazan 1‐oxide, C6H2Cl2N2O2, (I), and 4,7‐dibromobenzo[c]furazan 1‐oxide, C6H2Br2N2O2, (II), are normal. Compound (I) occurs in two polymorphic forms. One polymorph contains one molecule in the asymmetric unit, organized into two‐dimensional sheets involving intermolecular N?Cl and O?Cl interactions. The second polymorph has three molecules in the asymmetric unit, organized into two crystallographically different two‐dimensional sheets with similar interactions. Compound (II) is isomorphous with the second polymorph of (I). The three two‐dimensional sheets in the two polymorphs comprise a set of three two‐dimensional polymorphic arrangements. 相似文献
15.
George Ferguson Christopher Glidewell John Nicolson Low James L Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):692-694
The title compound, C14H14O2S2, contains discrete molecules and is a polymorph of a structure reported previously by Caputo, Palumbo, Nardelli & Pelizzi [Gazz. Chim. Ital. (1984), 114 , 421–430]. The present structure contains no intermolecular C—H?O hydrogen bonds, whereas in the previous polymorph, the molecules are linked into continuous chains by such interactions. 相似文献
16.
Graham Smith Urs D. Wermuth Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o694-o698
The structures of two compounds of l ‐tartaric acid with quinoline, viz. the proton‐transfer compound quinolinium hydrogen (2R,3R)‐tartrate monohydrate, C9H8N+·C4H5O6−·H2O, (I), and the anhydrous non‐proton‐transfer adduct with quinaldic acid, bis(quinolinium‐2‐carboxylate) (2R,3R)‐tartaric acid, 2C10H7NO2·C4H6O6, (II), have been determined at 130 K. Compound (I) has a three‐dimensional honeycomb substructure formed from head‐to‐tail hydrogen‐bonded hydrogen tartrate anions and water molecules. The stacks of π‐bonded quinolinium cations are accommodated within the channels and are hydrogen bonded to it peripherally. Compound (II) has a two‐dimensional network structure based on pseudo‐centrosymmetric head‐to‐tail hydrogen‐bonded cyclic dimers comprising zwitterionic quinaldic acid species which are interlinked by tartaric acid molecules. 相似文献
17.
Yun Shan Peng Han Sheng Xu Pance Naumov S. Shanmuga Sundara Raj Hoong‐Kun Fun Ibrahim Abdul Razak Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1386-1388
The title compound, C10H9NO2Se, crystallizes as flat molecules linked by selenium–oxygen interactions [Se?O = 3.189 (4) Å] into a linear chain along the a axis of the triclinic cell. The bond dimensions that are derived from ab initio geometry optimization calculations are similar to those determined from the diffraction measurements. 相似文献
18.
Tali Lavy Yana Sheynin Moshe Kapon Menahem Kaftory 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o50-o53
The crystal structures of three 1:2 inclusion compounds that consist of host molecule 2,5‐diphenylhydroquinone (C18H14O2) and the guest molecules 2‐pyridone (C5H5NO), 1,3‐diphenyl‐2‐propen‐1‐one (chalcone, C15H12O) and 1‐(4‐methoxyphenyl)‐3‐phenyl‐2‐propen‐1‐one (4′‐methoxychalcone, C16H14O2) were determined in order to study the ability of guest molecules in inclusion compounds to undergo photoreaction. All of the crystals were found to be photoresistant. The three inclusion compounds crystallize in triclinic space group . In each case, the host/guest ratio is 1:2, with the host molecules occupying crystallographic centers of symmetry and the guest molecules occupying general positions. The guest molecules in each of the inclusion compounds are linked to the host molecules by hydrogen bonds. In the inclusion compound where the guest molecule is pyridone, the host molecule is disordered so that the hydroxy groups are distributed between two different sites, with occupancies of 0.738 (3) and 0.262 (3). The pyridone molecules form dimers via N—H⋯O hydrogen bonds. 相似文献
19.
Katharine F. Bowes Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o1-o3
In the P polymorph of benzanilide or N‐phenylbenzamide, C13H11NO, the molecules are linked into simple C(4) chains by N—H⋯O hydrogen bonds. The molecules exhibit orientational disorder, but the donor and acceptor in a given hydrogen bond may occur, independently, in either the major or the minor orientation, such that all four possible N—H⋯O combinations have very similar geometries. The structure of this P polymorph can be related to that of a previously reported C2/c polymorph. 相似文献
20.
Simon J. Garden Marilza B. Corrêa Angelo C. Pinto James L. Wardell John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):o234-o238
In ethyl N‐[2‐(hydroxyacetyl)phenyl]carbamate, C11H13NO4, all of the non‐H atoms lie on a mirror plane in the space group Pnma; the molecules are linked into simple chains by a single C—H⋯O hydrogen bond. The molecules of ethyl N‐[2‐(hydroxyacetyl)‐4‐iodophenyl]carbamate, C11H12INO4, are linked into sheets by a combination of O—H⋯I and C—H⋯O hydrogen bonds and a dipolar I⋯O contact. Ethyl N‐[2‐(hydroxyacetyl)‐4‐methylphenyl]carbamate, C12H15NO4, crystallizes with Z′ = 2 in the space group P; pairs of molecules are weakly linked by an O—H⋯O hydrogen bond and these aggregates are linked into chains by two independent aromatic π–π stacking interactions. 相似文献