共查询到20条相似文献,搜索用时 15 毫秒
1.
Celeste Garcia Antonio Quesada Manuel Melguizo Justo Cobo Manuel Nogueras Adolfo Snchez Debbie Cannon John Nicolson Low 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1103-1105
The title compound, C9H12N2O3, crystallizes with two molecules in the asymmetric unit. There is extensive hydrogen bonding which results in the formation of a two‐dimensional corrugated sheet. This supramolecular structure is determined by the formation of hydrogen‐bonded chains resulting from the presence of a 6‐amino group and an ethoxycarbonyl group as substituents on a pyridine ring in relative para positions which constitute a π‐electron `push–pull' system. 相似文献
2.
Anirban Karmakar Ana E. Platero‐Prats Lars
hrstrm 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):251-254
The structure of 2,3,6,7,10,11‐hexahydroxytriphenylene (hhtp) methanol monosolvate, C18H12O6·CH3OH, has triclinic symmetry (space group P). The compound has a three‐dimensional layered network structure formed by intermolecular hydrogen bonding. Structure analysis with Hirshfeld surfaces is shown to be a sensitive method for comparing π‐stacking effects in the five known solvates of hhtp. The title structure shows slightly weaker π‐stacking than the dihydrate, but stronger π‐stacking than the other three solvates. 相似文献
3.
Matthew Polson Mark M. Turnbull Jan L. Wikaira 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1152-1156
The hydrobromide and hydrochloride salts of 2‐amino‐5‐iodopyridine were prepared from aqueous solutions. The hydrobromide salt, C5H6IN2+·Br−·0.5H2O, crystallizes as a hemihydrate, and exhibits hydrogen bonding and π‐stacking which stabilize the crystal structure. The hydrochloride salt, C5H6IN2+·Cl−·H2O·0.375HCl, crystallized as the hydrate and exhibits similar hydrogen bonding and π‐stacking in the lattice. The most interesting feature of the hydrochloride salt is the presence of an additional fractional HCl molecule which introduces disorder in the location of the water molecule. The additional proton from the fractional HCl molecule is accounted for by the presence of a partial hydronium ion on one of the water sites. 相似文献
4.
Marcilio S. S Cunha‐Filho Mariana Landin Ramon Martinez‐Pacheco Bruno Dacunha‐Marinho 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o473-o475
The most remarkable aspect of the crystal structure of the title compound (systematic name: 3,4‐dihydro‐2,2‐dimethyl‐2H‐naphtho[1,2‐b]pyran‐5,6‐dione), C15H14O3, is that a π‐stacking interaction is present between the two naphthalene ring systems of symmetry‐related molecules. Apart from these π–π interactions, different molecules are held together by weak C—H⋯O hydrogen‐bonding interactions. 相似文献
5.
Robin Brückner Patrick Pröhm Anja Wiesner Dr. Simon Steinhauer Dr. Carsten Müller Prof. Sebastian Riedel 《Angewandte Chemie (International ed. in English)》2016,55(36):10904-10908
The polychloride salt [CCl(NMe2)2]+2[Cl8]2? was synthesized and crystallized in the ionic liquid [BMP]OTf. The compound was fully characterized by Raman spectroscopy as well as X‐ray single‐crystal structure determination, and represents the first example of a polychloride dianion to be described. Detailed gas‐phase and solid‐state calculations concerning the nature of the bonding situation were also performed. 相似文献
6.
Andranne Bolduc Stphane Dufresne W. G. Skene 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(10):1196-1199
The title compound, C16H12N4S, forms a three‐dimensional layered network structure via intermolecular hydrogen bonding and π‐stacking. The azomethine molecule adopts the thermodynamically stable E regioisomer and the pyridine substituents are antiperiplanar. The mean planes of the pyridine rings and the azomethine group to which they are connected are twisted by 27.27 (5) and 33.60 (5)°. The electrochemical energy gap of 2.3 eV based on the HOMO–LUMO energy difference is in agreement with the spectroscopically derived value. 相似文献
7.
Fabio D. Cukiernik Andrs Zelcer Maria Teresa Garland Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(11):o604-o608
An interesting case of `halogen‐bonding‐promoted' crystal structure architecture is presented. The two title compounds, C8H8Br2O2 and C8H8I2O2, have almost indistinguishable molecular structures but very different spatial organization, and this is mainly due to differences in the halogen‐bonding interactions in which the different species present, i.e. Br and I, take part. The dibromo structure exhibits a π‐bonded columnar array involving all four independent molecules in the asymmetric unit, with intercolumnar interactions governed by C—Br...Br—C links and with no C—Br...O/N interactions present. In the diiodo structure, instead, the C—I...O synthon prevails, defining linear chains, in turn interlinked by C—I...I—C interactions. 相似文献
8.
Bhumasamudram Jagadish Michael D. Carducci Alice Dawson Gary S. Nichol Eugene A. Mash 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(8):o431-o433
The title methanol solvate, C24H22N4O5·CH3OH, forms an extended three‐dimensional hydrogen‐bonded structure, assisted by the presence of several good donor and acceptor sites. It shows none of the crystal packing features typically expected of piperazinediones, such as amide‐to‐amide R22(8) hydrogen bonding. In this structure the methanol solvent appears to play only a space‐filling role; it is not involved in any hydrogen bonding and instead is disordered over several sites. This study reports, to the best of our knowledge, the first crystal structure of an indane‐containing piperazinedione compound which exhibits a three‐dimensional hydrogen‐bonded structure formed by classical (N—H...O and N—H...N) hydrogen‐bonding interactions. 相似文献
9.
《Angewandte Chemie (International ed. in English)》2017,56(52):16484-16489
3H ‐1,2,3,4‐Triazaphosphole derivatives can be selectively alkylated with Meerwein's reagent at the most nucleophilic nitrogen atom. According to the principle of valence isoelectronicity, the corresponding phosphorus heterocycle represents the first formal phosphorus analogue of the well‐known 1,2,3‐triazolylidenes (mesoionic carbenes). Theoretical calculations revealed that the cation in triazaphospholenium tetrafluoroborate is an aromatic system with a high degree of π‐conjugation. First investigations showed that the cationic phosphorus heterocycle can stabilize a [Cu2Br4]2− dianion by formation of a neutral coordination compound with an unusual bonding situation between phosphorus and copper(I). 相似文献
10.
Manuela Ramos Silva Ana Matos Beja Jose Antonio Paixo Abilio J. F. N. Sobral Susana H. Lopes A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o572-o574
The title compound, C21H37NO2, is a new amphiphilic pyrrole with a long hydrocarbon chain, which will be used as a precursor for the synthesis of Langmuir–Blodgett films of porphyrins. Molecules related by an inversion centre are joined head‐to‐head into dimers by strong N—H?O hydrogen bonds. The dimers pack in the structure with their carbon chains parallel to one another, thereby forming alternating layers of carbon chains and pyrrole heads. The structure is further stabilized by two weak C—H?π intermolecular interactions, thereby saturating the hydrogen‐bonding capability of the aromatic π‐electron clouds. 相似文献
11.
Takayuki Iijima Masahiro Abe Take‐Aki Koizumi Atsushi Fukaya Kyohei Usami Kenichiro Kami Takakazu Yamamoto 《先进技术聚合物》2013,24(10):927-933
The reaction of 2,5‐diiodo‐1,4‐benzenedicarbonyl chloride, C6H2I2(COCl)2‐p, with 4‐hydroxy‐2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO‐ol) gave I–Ph(COO–TEMPO)2–I, Monomer‐1. Pd‐catalyzed polycondensation of Monomer‐1 with Me3Sn‐Th‐SnMe3 (2,5‐bis(trimethylstannyl)thiophene) and Bu3Sn–CH = CH–SnBu3 (1,2‐bis‐(tributylstannyl)ethylene) gave the corresponding π‐conjugated polymers, Polymer‐1 and Polymer‐2, respectively. Monomer‐1 was converted to a diethynyl compound, H–C ≡ C–Ph(COO–TEMPO)2–C ≡ C–H (Monomer‐1'), and Pd‐catalyzed polycondensation between Monomer‐1 and Monomer‐1' gave a π‐conjugated poly(arylene ethynylene) type polymer, Polymer‐3. According to the expansion of the π‐conjugation system by the polymerization, the UV–vis peaks of Monomer‐1 (λmax = 323 nm) and Monomer‐1' (327 nm) are shifted to longer wavelengths (λmax = 365 nm, 385 nm, and 396 nm for Polymer‐1, Polymer‐2, and Polymer‐3, respectively). Polymer‐1–Polymer‐3 showed ESR signals at about g = 2.01 with reasonable intensities. They are electrochemically active and showed a peak current anodic (oxidation) peak at about 0.9 V versus Ag/AgCl, which is reasonable for TEMPO polymers. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
12.
13.
Giuseppe Bruno Francesco Nicol Archimede Rotondo Francesco Foti Francesco Risitano Giovanni Grassi Cristina Bilardo 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):493-494
The crystal structure of the title compound, C17H10O3, is the first example of a furocoumarin containing three fused rings. The tricyclic furocoumarin fragment is perfectly planar. The phenyl substituent forms a dihedral angle of 39.52 (8)° with the plane of the tricyclic system. The crystal packing involves centrosymmetric dimers interconnected by strong π‐interactions between their furo[3,2‐c]coumarin fragments [at distances of 3.42 (4) Å]. 相似文献
14.
Abderrezak Addala David K. Geiger Zouaoui Setifi Fatima Setifi 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(3):348-353
The cocrystal salt tetraaquabis[trans‐1,2‐bis(pyridin‐4‐yl)ethene‐κN]iron(II) bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide)–trans‐1,2‐bis(pyridin‐4‐yl)ethene (1/2), [Fe(C12H10N2)2(H2O)4](C9H5N4O)2·2C12H10N2, is a rare example of a mononuclear FeII compound with trans‐1,2‐bis(pyridin‐4‐yl)ethane (bpe) ligands. The complex cation resides on a crystallographically imposed inversion center and exhibits a tetragonally distorted octahedral coordination geometry. Both the symmetry‐independent bpe ligand and the cocrystallized bpe molecule are essentially planar. The 1,1,3,3‐tetracyano‐2‐ethoxypropenide counter‐ion is nonplanar and the bond lengths are consistant with significant electron delocalization. The extended structure exhibits an extensive O—H…N hydrogen‐bonding network with layers of complex cations joined by the cocrystallized bpe. Both the coordinated and the cocrystallized bpe are involved in π–π interactions. Hirshfeld and fingerprint plots reveal the important intermolecular interactions. Density functional theory was used to estimate the strengths of the hydrogen‐bonding and π–π interactions, and suggest that the O—H…N hydrogen bonds enhance the strength of the π‐interactions by increasing the polarization of the pyridine rings. 相似文献
15.
Viktor Kettmann Jan Svtlík Jií Kubita 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o431-o433
In the title compound, C16H18N6O, an N‐carbonylimidazole derivative of pyrazoline‐1‐carboximidamide, the π‐electron density of the N atom in the 1‐position on the pyrazoline ring is delocalized through the amidine moiety and the adjacent carbonyl group. The imidazole ring, though coplanar with the rest of the molecule, is deconjugated. The pyrazoline ring adopts a flat‐envelope conformation, having the substituted phenyl ring oriented perpendicular to the mean plane of the heterocycle. Both of the two potential hydrogen‐bond donors are involved in intramolecular hydrogen‐bonding interactions. 相似文献
16.
Juan Saulo Gonzlez‐Gonzlez Itzia I. Padilla‐Martínez Efrn V. García‐Bez Olivia Franco‐Hernndez Francisco J. Martínez‐Martínez 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):66-69
In the title compound, C24H36N6O6·C2H6OS, the carbonyl groups are in an antiperiplanar conformation, with O=C—C=O torsion angles of 178.59 (15) and −172.08 (16)°. An intramolecular hydrogen‐bonding pattern is depicted by four N—H...O interactions, which form two adjacent S(5)S(5) motifs, and an N—H...N interaction, which forms an S(6) ring motif. Intermolecular N—H...O hydrogen bonding and C—H...O soft interactions allow the formation of a meso‐helix. The title compound is the first example of a helical 1,2‐phenylenedioxalamide. The oxalamide traps one molecule of dimethyl sulfoxide through N—H...O hydrogen bonding. C—H...O soft interactions give rise to the two‐dimensional structure. 相似文献
17.
Although the “brown‐ring” ion, [Fe(H2O)5(NO)]2+ ( 1 ), has been a research target for more than a century, this poorly stable species had never been isolated. We now report on the synthesis of crystals of a salt of 1 which allowed us to tackle the unique bonding situation on an experimental basis. As a result of the bonding analysis, two stretched, spin‐polarised π‐interactions provide the Fe–NO binding—and challenge the concept of “oxidation state”. 相似文献
18.
Thaer Assaad Mwaffak Rukiah 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(11):o469-o472
The structure of the title benzovesamicol analogue, C21H27N3O2, an important compound for the diagnosis of Alzheimer's disease, has been determined by X‐ray powder diffraction. The title compound was firstly synthesized and characterized by spectroscopic methods (FT–IR, and 13C and 1H NMR). The compound is a racemic mixture of enantiomers which crystallizes in the monoclinic system in a centrosymmetric space group (P21/c). Crystallography, in particular powder X‐ray diffraction, was pivotal in revealing that the enantio‐resolution did not succeed. The piperazine ring is in a chair conformation, while the cyclohexene ring assumes a half‐chair conformation. The crystal packing is dominated by intermolecular O—H...N hydrogen bonding which links molecules along the c direction. 相似文献
19.
Charmaine Arderne 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(5):526-528
The crystal structure of the title salt, C5H16N22+·2Br−, with Z = 12 and more unusually Z′ = 3, forms part of a small group of crystal structures in the Cambridge Structural Database that are ammonium bromide salts. One of the diaminium cation chains in the asymmetric unit exhibits positional disorder, which was modelled using a suitable disorder model. This compound also exhibits organic–inorganic layering in its packing arrangement that is typical of this class of compound. An extensive complex three‐dimensional hydrogen‐bonding network is also identified. The hydrogen bonds evident in this crystal structure were identified as being most likely strong charge‐assisted hydrogen bonds. 相似文献
20.
The synthetic route to the dimesitylpalladium(II) complex [(bpy)PdMes2] ( 1 ) (Mes = mesityl = 2,4,6‐trimethyl phenyl) does not only give the desired compound but also the 6‐mesityl‐2,2′bipyridyldimesitylpalladium [(6‐Mes‐bpy)PdMes2] ( 2 ) complex and the free ligand 6,6′‐dimesityl‐2,2′‐bipyridine in reasonable yields. Single crystals of 2 were examined by X‐Ray diffraction. The compound reveals a sterically crowded molecular structure. An intramolecular π‐stacking interaction was found between the mesityl substituent on the bipyridine ligand and the adjacent mesityl ligand. The electrochemical behaviour of 1 and 2 together with a related compound was examined at various temperatures showing two reversible reduction reactions and reversible one‐electron oxidation steps at low temperatures. The latter are assigned to PdII/PdIII couples. 相似文献