共查询到20条相似文献,搜索用时 15 毫秒
1.
M. L. Rodríguez M. Febles C. Prez N. Prez‐Hernndez J. D. Martín C. Foces‐Foces 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o138-o142
In the hydrogen‐bonding networks of 8‐hydroxy‐5‐hydroxymethyl‐3,6‐dioxatricyclo[6.3.1.01.5]dodecan‐2‐one and 5,7‐bis(hydroxymethyl)‐3,6‐dioxatricyclo[5.3.1.01.5]undecan‐2‐one, both C11H16O5, layers and double strands, respectively, lead to the formation of chains connected by hydroxy‐to‐hydroxy contacts, where the hydroxymethyl group, present in both structures, acts as a donor. The secondary structures differ in the hydrogen bonding of these chains via the second hydroxy group, which is involved in hydroxy‐to‐carbonyl and hydroxy‐to‐hydroxy bonds, respectively. 相似文献
2.
Kasthuri Balasubramani Packianathan Thomas Muthiah Urszula Rychlewska Agnieszka Plutecka 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):o586-o588
The title compound, 2,4‐diamino‐5‐(4‐chlorophenyl)‐6‐ethylpyrimidine‐1,3‐diium dinitrate, C12H15ClN42+·2NO3−, contains two crystallographically independent pyrimethamine (PMN) molecules, which differ in the relative orientations of the pyrimidine and benzene rings and of the ethyl substitutents. In both pyrimethamine molecules, all the pyrimidine N atoms are protonated, unlike most related compounds, in which only one pyrimidine N atom is protonated. The two pyrimethamine moieties are bridged by a variety of N—H⋯O(nitrate) interactions, including some three‐centre hydrogen bonds. 相似文献
3.
Diana Becerra Braulio Insuasty Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(2):o79-o86
The molecules of racemic 3‐benzoylmethyl‐3‐hydroxyindolin‐2‐one, C16H13NO3, (I), are linked by a combination of N—H...O and O—H...O hydrogen bonds into a chain of centrosymmetric edge‐fused R22(10) and R44(12) rings. Five monosubstituted analogues of (I), namely racemic 3‐hydroxy‐3‐[(4‐methylbenzoyl)methyl]indolin‐2‐one, C17H15NO3, (II), racemic 3‐[(4‐fluorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C16H12FNO3, (III), racemic 3‐[(4‐chlorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C16H12ClNO3, (IV), racemic 3‐[(4‐bromobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C16H12BrNO3, (V), and racemic 3‐hydroxy‐3‐[(4‐nitrobenzoyl)methyl]indolin‐2‐one, C16H12N2O5, (VI), are isomorphous in space group P. In each of compounds (II)–(VI), a combination of N—H...O and O—H...O hydrogen bonds generates a chain of centrosymmetric edge‐fused R22(8) and R22(10) rings, and these chains are linked into sheets by an aromatic π–π stacking interaction. No two of the structures of (II)–(VI) exhibit the same combination of weak hydrogen bonds of C—H...O and C—H...π(arene) types. The molecules of racemic 3‐hydroxy‐3‐(2‐thienylcarbonylmethyl)indolin‐2‐one, C14H11NO3S, (VII), form hydrogen‐bonded chains very similar to those in (II)–(VI), but here the sheet formation depends upon a weak π–π stacking interaction between thienyl rings. Comparisons are drawn between the crystal structures of compounds (I)–(VII) and those of some recently reported analogues having no aromatic group in the side chain. 相似文献
4.
Packianathan Thomas Muthiah Kasthuri Balasubramani Urszula Rychlewska Agnieszka Plutecka 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):o605-o607
In the crystal structure of the title compound, C6H10N3+·C7H5O3−, the asymmetric unit contains four crystallographically independent 2‐amino‐4,6‐dimethylpyrimidinium and salicylate ions (Z = 8). In each of these, one of the pyrimidine N atoms is protonated, and the carboxylate group of the salicylate ion interacts with the pyrimidine group through a pair of N—H⋯O hydrogen bonds, forming an R22(8) motif. The pyrimidine cations also form base pairs via a pair of N—H⋯N hydrogen bonds (involving the amino group and the unprotonated ring N atom), forming another R22(8) motif. Three such R22(8) motifs, fused together, constitute a closed cyclic aggregate, and the linking of these aggregates, arranged in consecutive layers, can be analysed in terms of off‐face stacking interactions. 相似文献
5.
Henry Insuasty Edison Castro Edison Snchez Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):o141-o146
In O‐ethyl N‐benzoylthiocarbamate, C10H11NO2S, the molecules are linked into sheets by a combination of two‐centre N—H...O and C—H...S hydrogen bonds and a three‐centre C—H...(O,S) hydrogen bond. A combination of two‐centre N—H...O and C—H...O hydrogen bonds links the molecules of O‐ethyl N‐(4‐methylbenzoyl)thiocarbamate, C11H13NO2S, into chains of rings, which are linked into sheets by an aromatic π–π stacking interaction. In O,S‐diethyl N‐(4‐methylbenzoyl)imidothiocarbonate, C13H17NO2S, pairs of molecules are linked into centrosymmetric dimers by pairs of symmetry‐related C—H...π(arene) hydrogen bonds, while the molecules of O,S‐diethyl N‐(4‐chlorobenzoyl)imidothiocarbonate, C12H14ClNO2S, are linked by a single C—H...O hydrogen bond into simple chains, pairs of which are linked by an aromatic π–π stacking interaction to form a ladder‐type structure. 相似文献
6.
Maria E. Sulbaran Gerzon E. Delgado Asilo J. Mora Ali Bahsas Hector Novoa de Armas Norbert Blaton 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(9):o543-o545
In the title compound, C6H8N2O2S, also known as N‐acetyl‐2‐thiohydantoin–alanine, the molecules are joined by N—H...O hydrogen bonds, forming centrosymmetric R22(8) dimers; these dimers are linked by C—H...O interactions to form R22(10) rings, thus forming C22(10) chains that run along the [101] direction. 相似文献
7.
Dominik Cin
i Branko Kaitner 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):o101-o104
In the title compounds, C7H8NO2+·Br−, (I), and C7H8NO2+·I−, (II), the asymmetric unit contains a discrete 3‐carboxyanilinium cation, with a protonated amine group, and a halide anion. The compounds are not isostructural, and the crystal structures of (I) and (II) are characterized by different two‐dimensional hydrogen‐bonded networks. The ions in (I) are connected into ladder‐like ribbons via N—H...Br hydrogen bonds, while classic cyclic O—H...O hydrogen bonds between adjacent carboxylic acid functions link adjacent ribbons to give three characteristic graph‐set motifs, viz. C21(4), R42(8) and R22(8). The ions in (II) are connected via N—H...I, N—H...O and O—H...I hydrogen bonds, also with three characteristic graph‐set motifs, viz. C(7), C21(4) and R42(18), but an O—H...O interaction is not present. 相似文献
8.
Barbara Hachua Maria Nowak Joachim Kusz 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(7):o357-o360
The crystal structure of the title compound, C10H12O4·H2O, consists of (3,4‐dimethoxyphenyl)acetic acid and water molecules linked by O—H...O hydrogen bonds to form cyclic structures with graph‐set motifs R12(5) and R44(12). These hydrogen‐bond patterns result in a three‐dimensional network with graph‐set motifs R44(20) and R44(22), and the formation of larger macrocycles, respectively. The C—C bond lengths and the endocyclic angles of the benzene ring show a noticeable asymmetry, which is connected with the charge‐transfer interaction of the carboxyl or methoxy groups and the benzene ring. The title compound is one of the simple carboxylic acid systems that form hydrates. Thus, the significance of this study lies in the analysis of the interactions in this structure and the aggregations occurring via hydrogen bonds in two crystalline forms of (3,4‐dimethoxyphenyl)acetic acid, namely the present hydrate and the anhydrous form [Chopra, Choudhury & Guru Row (2003). Acta Cryst. E 59 , o433–o434]. The correlation between the IR spectrum of this compound and its structural data are also discussed. 相似文献
9.
Benyong Lou Dan Bostrm Sitaram P. Velaga 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):o714-o716
Atenolol {or 4‐[2‐hydroxy‐3‐(isopropylamino)propoxy]phenylacetamide} crystallizes with 4‐aminobenzoic acid to give the salt {3‐[4‐(aminocarbonylmethyl)phenoxy]‐2‐hydroxypropyl}isopropylammonium 4‐aminobenzoate monohydrate, C14H23N2O3+·C7H6NO2−·H2O. In the crystal structure, the water molecule, the carboxylate group of 4‐aminobenzoate, and the hydroxy and ether O atoms of atenolol form a supramolecular R33(11) heterosynthon. Three other types of supramolecular synthons link the asymmetric unit into a two‐dimensional structure. 相似文献
10.
11.
The condensation of 5‐[4′‐(2″‐halo‐ethoxy)benzylidenyl]‐2,4‐thiazolidinediones 2 when separately carried with different 2‐amino thiazoles 3 and different sulphanilamides 4 in DMF, using potassium hydroxide in the presence of a catalytic amount of a phase transfer catalyst, gave new 5‐[4′‐(4″‐aryl‐thiazol‐2″‐yl‐aminoethoxy)‐3′/5′‐substituted benzylidenyl]‐2,4‐thiazolidinediones 5 and 5‐[4′‐(2″/4″‐sulphonamidophenyl aminoethoxy)‐3′/5′‐substituted benzylidenyl]‐2,4‐thiazolidinediones 6 derivatives in good yields, respectively. The structures of all new compounds were established from analytical and spectral data. All the reaction sequences were carried under microwave irradiation, as an efficient tool. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:151–156, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20528 相似文献
12.
H. Raissi A. F. Jalbout M. Fazli M. Yoosefian H. Ghiassi Z. Wang A. de Leon 《International journal of quantum chemistry》2009,109(7):1497-1504
Intramolecular H‐bonds existing for derivatives of 3‐amino‐propenethial have been studied using the B3LYP/6‐311++G** level of theory. The nature of these interactions, known as resonance assisted hydrogen bonds, has been discussed. The topological properties of the electron density distributions for N—H—S intramolecular bridges have been analyzed in terms of the Bader theory of atoms in molecules. Correlations between the H‐bond strength and topological parameters have been also studied. Furthermore, we obtained the exact value of the intramolecular hydrogen bond energies by the related rotamers method. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 相似文献
13.
14.
Gerson Lpez L. Marina Jaramillo Rodrigo Abonia Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(4):o168-o173
The molecules of N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐2‐chloro‐N‐(4‐methoxybenzyl)acetamide, C23H26ClN3O2, are linked into a chain of edge‐fused centrosymmetric rings by a combination of one C—H...O hydrogen bond and one C—H...π(arene) hydrogen bond. In N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐2‐chloro‐N‐(4‐chlorobenzyl)acetamide, C22H23Cl2N3O, a combination of one C—H...O hydrogen bond and two C—H...π(arene) hydrogen bonds, which utilize different aryl rings as the acceptors, link the molecules into sheets. The molecules of S‐[N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐N‐(4‐methylbenzyl)carbamoyl]methyl O‐ethyl carbonodithioate, C26H31N3O2S2, are also linked into sheets, now by a combination of two C—H...O hydrogen bonds, both of which utilize the amide O atom as the acceptor, and two C—H...π(arene) hydrogen bonds, which utilize different aryl groups as the acceptors. 相似文献
15.
Joanna Meszko Artur Sikorski Olexyj M. Huta Antoni Konitz Jerzy Baejowski 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):o669-o671
The title compounds, C14H12N+·CH3O4S?, (I), and C15H14N+·CH3O4S?, (II), respectively, crystallize with the planar 10‐methylacridinium or 9,10‐dimethylacridinium cations arranged in layers, parallel to the twofold axis in (I) and perpendicular to the 21 axis in (II). Adjacent cations in both compounds are packed in a `head‐to‐tail' manner. The methyl sulfate anion only exhibits planar symmetry in (II). The cations and anions are linked through C—H?O interactions involving three O atoms of the anion, six acridine H atoms and the CH3 group on the N atom in (I), and the four O atoms of the anion, three acridine H atoms and the carbon‐bound CH3 group in (II). The methyl sulfate anions are oriented differently in the two compounds relative to the cations, being nearly perpendicular in (I) but parallel in (II). Electrostatic interaction between the ions and the network of C—H?O interactions leads to relatively compact crystal lattices in both structures. 相似文献
16.
17.
S. Athimoolam S. Natarajan 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):o283-o286
The title adduct, 4‐aminobenzoic acid–l ‐proline–water (1/2/1), C7H7NO2·2C5H9NO2·H2O, contains two independent proline chains with a C(5) motif, each of the head‐to‐tail type and each held together by N—H...O hydrogen bonds, propagated parallel to the b and c axes of the unit cell. Thus, the proline residues aggregate parallel to the ac plane. 4‐Aminobenzoic acid (PABA) residues are arranged on both sides of the proline aggregate and are connected through water O atoms, which act as acceptors for PABA and as hydrogen‐bond donors to the amino acids. The characteristic features of PABA, viz. twisting of the carboxyl plane from the aromatic ring and the formation of a head‐to‐tail chain motif [C(8)] along the b axis, are observed. A distinct feature of the structure is that no proton transfer occurs between proline and PABA. 相似文献
18.
Dorota Prukala Igor Khmelinskii Jacek Koput Mateusz Gierszewski Tomasz Pędziński Marek Sikorski 《Photochemistry and photobiology》2014,90(5):972-988
The photophysical properties of 5‐deazaalloxazine and 1,3‐dimethyl‐5‐deazaalloxazine were studied in different solvents. These compounds have higher values of fluorescence quantum yields and longer fluorescence lifetimes, compared to those obtained for their alloxazine analogs. Electronic structure and S0–Si transitions were investigated using the ab initio methods [MP2, CIS(D), EOM‐CCSD] with the correlation‐consistent basis sets. Also the time‐dependent density functional theory (TD‐DFT) has been employed. The lowest singlet excited states of 5‐deazaalloxazine and 1,3‐dimethyl‐5‐deazaalloxazine are predicted to have the π, π* character, whereas similar alloxazines have two close‐lying π, π* and n, π* transitions. Experimental steady‐state and time‐resolved spectral studies indicate formation of an isoalloxazinic excited state via excited‐state double‐proton transfer (ESDPT) catalyzed by an acetic acid molecule that forms a hydrogen bond complex with the 5‐deazaalloxazine molecule. Solvatochromism of both 5‐deazaalloxazine and its 1,3‐dimethyl substituted derivative was analyzed using the Kamlet–Taft scale and four‐parameter Catalán solvent scale. The most significant result of our studies is that the both scales show a strong influence of solvent acidity (hydrogen bond donating ability) on the emission properties of these compounds, indicating the importance of intermolecular solute–solvent hydrogen‐bonding interactions in their excited state. 相似文献
19.
James L. Balderson Manuel A. Fernandes Joseph P. Michael Christopher B. Perry 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):o734-o738
The title compounds, namely (2Z)‐1‐(4‐bromophenyl)‐2‐(pyrrolidin‐2‐ylidene)ethanone, C12H12BrNO, (I), (2Z)‐1‐(4‐bromophenyl)‐2‐(piperidin‐2‐ylidene)ethanone, C13H14BrNO, (II), and (2Z)‐2‐(azepan‐2‐ylidene)‐1‐(4‐bromophenyl)ethanone, C14H16BrNO, (III), are characterized by bifurcated intra‐ and intermolecular hydrogen bonding between the secondary amine and carbonyl groups. The former establishes a six‐membered hydrogen‐bonded ring, while the latter leads to the formation of centrosymmetric dimers. Weak C—H...Br interactions link the individual molecules into chains that run along the [011], [101] and [101] directions in (I)–(III), respectively. Additional weak Br...O, C—H...π and C—H...O interactions further stabilize the crystal structures. 相似文献
20.
Faramarz Rostami‐Charati Zinatossadat Hossaini Mohammad A. Khalilzadeh Hojatollah Jafaryan 《Journal of heterocyclic chemistry》2012,49(1):217-220
A one‐pot synthesis of pyrrole derivatives via reaction between activated carbonyl compounds, primary amines, and 1,3‐dicarbonyls under solvent‐free conditions is described. J. Heterocyclic Chem., (2012). 相似文献