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1.
Pierre Martin 《Helvetica chimica acta》1988,71(2):344-347
Synthesis of Natural, Halogenated Indoles via Hetero-Cope Rearrangement of Vinyl N-Phenylhydroxamates An efficient method for the synthesis of natural 4-chloro-6-methoxyindole (the promutagen from fava beans) and of the two 4,6- dibromo- and 3,4,6-tribromoindoles (produced by acorn worms, Enteropneusta) is presented. The key step is a hetero-Cope rearrangement of the intermediate N-phenyl-O-vinylhydroxylamine derivatives. 相似文献
2.
Ying‐Quan Zou Xia Li Yan Li Huai‐Ming Hu 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1048-1050
The title compound, tetrakis(μ‐2,3‐dimethoxybenzoato)‐κ4O:O′;κ6O,O′:O′‐bis[(2,2′‐bipyridine‐N,N′)(2,3‐dimethoxybenzoato‐O,O′)lanthanum(III)], [La2(2,3‐DMOBA)6(2,2′‐bpy)2], where 2,3‐DMOBA is 2,3‐dimethoxybenzoate (C9H9O4) and 2,2′‐bpy is 2,2′‐bipyridine (C10H8N2), is a dimer with a centre of inversion between the La atoms bridged by four carboxylate ligands. The central La atom is ennea‐coordinated and has a distorted monocapped square‐antiprism geometry. 相似文献
3.
Crystal structure of a calcium(II) complex with pyrazine-2,3-dicarboxylate,nitrate and water ligands
《Journal of Coordination Chemistry》2012,65(10):891-898
The structure of catena-[tris(aquo-O)(nitrato-O,O′)(µ-hydrogen pyrazine-2,3-dicarboxylato-O,N–O′,N′)calcium(II)][tetra(aquo-O)(μ-hydrogen pyrazine-2,3-dicarboxylato-O,N–O′,N′) calcium(I)] nitrate, {Ca[H(2,3-PZDC)](H3O)3(NO3)}{Ca[H(2,3-PZDC)](H2O)4}+ (NO3)?, is composed of molecular ribbons in which calcium atoms are bridged by both N,O-bonding moieties of singly deprotonated ligand molecules. The hydrogen atom donated by one carboxylic group is linked by a short intramolecular hydrogen bond of 2.37 Å to an oxygen atom of the second carboxylic group of the same ligand. Two crystallographically independent Ca(II) ions exhibit different coordination modes. One is coordinated by two bonding moieties of the bridging ligand molecules, three water oxygen atoms and two oxygen atoms of a nitrate ligand. The other calcium ion is chelated by two bonding moieties donated by the bridging ligand molecules and four water oxygen atoms, forming a positively charged assembly with a nitrate anion located nearby. The coordination polyhedron of the first calcium ion is a strongly deformed bicapped pentagonal bipyramid with nine-coordinated atoms; the second calcium ion is also in a strongly deformed pentagonal bipyramid with one apex on one side of the equatorial plane and two apices on the other. Coordinated water oxygen atoms act as donors in a hydrogen-bond network. 相似文献
4.
Hong‐Tao Zhang Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):m313-m314
The asymmetric unit of the title one‐dimensional coordination polymer, catena‐poly[[μ‐pyridine‐2,3‐dicarboxylato‐1κO:2κ2N,O′‐bis[diaquacobalt(II)]]‐μ‐pyridine‐2,3‐dicarboxylato‐1κ2N,O:2κO′:1′κO′], [Co(C7H3NO4)(H2O)2]n, is composed of a cobalt(II) ion, a pyridine‐2,3‐dicarboxylate dianion and two water molecules. The polymer has a zigzag structure consisting of a chain of edge‐fused rings, and the polymer chains are linked by O—H⃛O hydrogen bonds into a three‐dimensional framework. 相似文献
5.
Grigorii G. Sivets Elena N. Kalinichenko Igor A. Mikhailopulo 《Helvetica chimica acta》2007,90(9):1818-1836
Convergent syntheses of the 9‐(3‐X‐2,3‐dideoxy‐2‐fluoro‐β‐D ‐ribofuranosyl)adenines 5 (X=N3) and 7 (X=NH2), as well as of their respective α‐anomers 6 and 8 , are described, using methyl 2‐azido‐5‐O‐benzoyl‐2,3‐dideoxy‐2‐fluoro‐β‐D ‐ribofuranoside ( 4 ) as glycosylating agent. Methyl 5‐O‐benzoyl‐2,3‐dideoxy‐2,3‐difluoro‐β‐D ‐ribofuranoside ( 12 ) was prepared starting from two precursors, and coupled with silylated N6‐benzoyladenine to afford, after deprotection, 2′,3′‐dideoxy‐2′,3′‐difluoroadenosine ( 13 ). Condensation of 1‐O‐acetyl‐3,5‐di‐O‐benzoyl‐2‐deoxy‐2‐fluoro‐β‐D ‐ribofuranose ( 14 ) with silylated N2‐palmitoylguanine gave, after chromatographic separation and deacylation, the N7‐β‐anomer 17 as the main product, along with 2′‐deoxy‐2′‐fluoroguanosine ( 15 ) and its N9‐α‐anomer 16 in a ratio of ca. 42 : 24 : 10. An in‐depth conformational analysis of a number of 2,3‐dideoxy‐2‐fluoro‐3‐X‐D ‐ribofuranosides (X=F, N3, NH2, H) as well as of purine and pyrimidine 2‐deoxy‐2‐fluoro‐D ‐ribofuranosyl nucleosides was performed using the PSEUROT (version 6.3) software in combination with NMR studies. 相似文献
6.
Yunyun Yang Wenxiang Chai Li Song Jian Lin 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(9):m293-m296
The title dinuclear complex, (aqua‐1κO)tetrakis(μ‐2,3‐diphenylprop‐2‐enoato‐1:2κ2O:O′)bis(2,3‐diphenylprop‐2‐enoato)‐1κO;2κO‐(ethanol‐2κO)bis(1,10‐phenanthroline)‐1κ2N,N′;2κ2N,N′‐dilanthanum(III), [La2(C15H11O2)6(C12H8N2)2(C2H5OH)(H2O)], contains two similar LaIII centres with distorted [LaO6N2] bicapped triganol–prismatic coordination polyhedra formed by six phenylcinnamate (PCA− or 2,3‐diphenylprop‐2‐enoate) ligands, two 1,10‐phenanthroline (phen) ligands, a coordinating ethanol molecule and a coordinating water molecule. The two metal centres are bridged by four μ‐PCA− ligands, with the remaining two PCA− ligands coordinated in a monodentate fashion. The noncoordinated carboxylate O atoms on the terminal PCA− ligands form O—H...O hydrogen bonds with the coordinated solvent molecules. Each La centre is also coordinated by a bidentate phen ligand. The PCA− ligands all adopt syn–syn orientations, with the two phenyl rings presenting dihedral angles of about 70°. The compound displays photochromic behaviour both in solution and in the solid state. 相似文献
7.
Malitsatsi J. Mnguni Andreas Lemmerer 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(2):103-109
Six derivatives of 4‐amino‐1,5‐dimethyl‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐3‐one (4‐aminoantipyrine), C11H13N3O, (I), have been synthesized and structurally characterized to investigate the changes in the observed hydrogen‐bonding motifs compared to the original 4‐aminoantipyrine. The derivatives were synthesized from the reactions of 4‐aminoantipyrine with various aldehyde‐, ketone‐ and ester‐containing molecules, producing (Z)‐methyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]but‐2‐enoate, C16H19N3O3, (II), (Z)‐ethyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]but‐2‐enoate, C17H21N3O3, (III), ethyl 2‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]cyclohex‐1‐enecarboxylate, C20H25N3O3, (IV), (Z)‐ethyl 3‐[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]‐3‐phenylacrylate, C22H23N3O3, (V), 2‐cyano‐N‐(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)acetamide, C14H14N4O2, (VI), and (E)‐methyl 4‐{[(1,5‐dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)amino]methyl}benzoate, C20H19N3O3, (VII). The asymmetric units of all these compounds have one molecule on a general position. The hydrogen bonding in (I) forms chains of molecules via intermolecular N—H...O hydrogen bonds around a crystallographic sixfold screw axis. In contrast, the formation of enamines for all derived compounds except (VII) favours the formation of a six‐membered intramolecular N—H...O hydrogen‐bonded ring in (II)–(V) and an intermolecular N—H...O hydrogen bond in (VI), whereas there is an intramolecular C—H...O hydrogen bond in the structure of imine (VII). All the reported compounds, except for (II), feature π–π interactions, while C—H...π interactions are observed in (II), C—H...O interactions are observed in (I), (III), (V) and (VI), and a C—O...π interaction is observed in (II). 相似文献
8.
d-Mannose was treated with dry acetone in the presence of conc. H2SO4 to afford 2,3:5,6-di-O-isopropylidene-α-d-mannofuranoside. Treating the latter with ethyl chloroacetate gave carboethoxymethyl 2,3:5,6-di-O-isopropylidene-α-d-mannofuranoside, which was hydrolyzed with N2H4 · H2O to afford the acid hydrazide derivative. Treating of the acid hydrazide with acylated amino acides, via the azide-coupling method afforded the corresponding O-glycopeptides. Reaction of the glycopeptide methyl esters with N2H4 · H2O afforded the corresponding hydrazides, which were coupled with the amino acid methyl esters to afford the dipeptides. Deprotection
was carried out by using 70% AcOH. The prepared O-glycopeptides were tested for antiviral activity against hepatitis B virus and showed moderate activities. 相似文献
9.
G. Pelosi C. Pelizzi M. Belicchi Ferrari M. C. Rodríguez‐Argüelles C. Vieito J. Sanmartín 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):o589-o592
The two title semicarbazones, namely 2,3‐dihydro‐1H‐indole‐2,3‐dione 3‐semicarbazone, C9H8N4O2, (I), and 1‐methyl‐2,3‐dihydro‐1H‐indole‐2,3‐dione 3‐semicarbazone, C10H10N4O2, (II), show the same configuration, viz. Z around the imine C=N bond and E around the C(O)—NH2 bond, stabilized by two intramolecular hydrogen bonds. The presence of a methyl group on the isatin N atom determines the difference in the packing; in (I), the molecules are linked into chains which lie in the crystallographic (102) plane and run perpendicular to the b axis, while in (II), the molecules are arranged to form helices running parallel to a crystallographic screw axis in the a direction. 相似文献
10.
Summary.
d-Mannose was treated with dry acetone in the presence of conc. H2SO4 to afford 2,3:5,6-di-O-isopropylidene-α-d-mannofuranoside. Treating the latter with ethyl chloroacetate gave carboethoxymethyl 2,3:5,6-di-O-isopropylidene-α-d-mannofuranoside, which was hydrolyzed with N2H4 · H2O to afford the acid hydrazide derivative. Treating of the acid hydrazide with acylated amino acides, via the azide-coupling method afforded the corresponding O-glycopeptides. Reaction of the glycopeptide methyl esters with N2H4 · H2O afforded the corresponding hydrazides, which were coupled with the amino acid methyl esters to afford the dipeptides. Deprotection
was carried out by using 70% AcOH. The prepared O-glycopeptides were tested for antiviral activity against hepatitis B virus and showed moderate activities. 相似文献
11.
Mohammad Ghadermazi Jafar Attar Gharamaleki Marilyn M. Olmstead Mehdi Almasi 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(7):539-544
The reaction of the proton‐transfer compound piperazine‐1,4‐diium pyrazine‐2,3‐dicarboxylate 4.5‐hydrate, C4H12N22+·C6H2N2O42−·4.5H2O or (pipzH2)(pyzdc)·4.5H2O (pyzdcH2 is pyrazine‐2,3‐dicarboxylic acid and pipz is piperazine), (I), with Zn(NO3)2·6H2O and CoCl2·6H2O results in the formation of bis(piperazine‐1,4‐diium) bis(μ‐pyrazine‐2,3‐dicarboxylato)‐κ3N1,O2:O3;κ3O3:N1,O2‐bis[aqua(pyrazine‐2,3‐dicarboxylato‐κ2N1,O2)zinc(II)] decahydrate, (C4H12N2)2[Zn2(C6H2N2O4)4(H2O)2]·10H2O or (pipzH2)2[Zn(pyzdc)2(H2O)]2·10H2O, (II), and catena‐poly[piperazine‐1,4‐diium [cobalt(II)‐bis(μ‐pyrazine‐2,3‐dicarboxylato)‐κ3N1,O2:O3;κ3O3:N1,O2] hexahydrate], {(C4H12N2)[Co(C6H2N2O4)2]·6H2O}n or {(pipzH2)[Co(pyzdc)2]·6H2O}n, (III), respectively. In (I), pyzdcH2 is doubly deprotonated on reaction with piperazine as a base. Compound (II) crystallizes as a dimer, whereas compound (III) exists as a one‐dimensional coordination polymer. In (II), two pyzdc2− groups chelate to each of the two ZnII atoms through a ring N atom and an O atom of the 2‐carboxylate group. In one ligand, the adjacent 3‐carboxylate group bridges to a neighbouring metal atom. A water molecule ligates in the sixth coordination site. The structure of (II) can be described as a commensurate superlattice due to an ordering in the hydrogen‐bonded network. In (III), no water is coordinated to the metal atom and the coordination sphere is comprised of two N,O‐chelates plus two bridging O atoms. A large number of hydrogen bonds are observed in all three compounds. These interactions, as well as π–π and C=O...π stacking interactions, play important structural roles. 相似文献
12.
Jun Xia Xiao‐Lin Gong Xing Fan 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(10):878-882
Assemblies of pyrazine‐2,3‐dicarboxylic acid and CdII in the presence of bis(1,2,4‐triazol‐1‐yl)butane or bis(1,2,4‐triazol‐1‐yl)ethane under ambient conditions yielded two new coordination polymers, namely poly[[tetraaqua[μ2‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane‐κ2N4:N4′]bis(μ2‐pyrazine‐2,3‐dicarboxylato‐κ3N1,O2:O3)dicadmium(II)] dihydrate], {[Cd2(C6H2N2O4)2(C8H12N6)(H2O)4]·2H2O}n, (I), and poly[[diaqua[μ2‐1,2‐bis(1,2,4‐triazol‐1‐yl)ethane‐κ2N4:N4′]bis(μ3‐pyrazine‐2,3‐dicarboxylato‐κ4N1,O2:O3:O3′)dicadmium(II)] dihydrate], {[Cd2(C6H2N2O4)2(C6H8N6)(H2O)2]·2H2O}n, (II). Complex (I) displays an interesting two‐dimensional wave‐like structure and forms a distinct extended three‐dimensional supramolecular structure with the help of O—H...N and O—H...O hydrogen bonds. Complex (II) has a three‐dimensional framework structure in which hydrogen bonds of the O—H...N and O—H...O types are found. 相似文献
13.
Angelo Mugnoli Alberto Borassi Andrea Spallarossa Sara Cesarini 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):o315-o317
In the crystal structure of the novel acylthiocarbamate derivative O‐[2‐(1,3‐dioxo‐2,3‐dihydro‐1H‐isoindol‐2‐yl)ethyl] N‐(4‐methylphenyl)‐N‐(3‐nitrobenzoyl)thiocarbamate, C25H19N3O6S, intra‐ and intermolecular π–π interactions occur between the phthalimide and N‐benzoyl moieties. The partial atomic charges, calculated by ab initio methods, are consistent with the observed structure. 相似文献
14.
Summary The reaction of 3-iodo-4-methoxy-2(1H)-quinolinone (1) and 3-iodo-4,6,8-trimethoxy-2(1H)-quinolinone (2) with 2-methyl-3-butyn-2-ol under modified Heck-conditions gave the 2-substituted derivatives 2-(1-hydroxy-1-methylethyl)-4-methoxyfuro[2,3-b]-quinoline (3) and 2-(1-hydroxy-1-methylethyl-4,6,8-trimethoxyfuro[2,3-b]-quinoline (4). By a subsequent hydrogenation-reaction with a homogeneous catalyst (PtO2/Rh2O3), the furoquinoline-derivatives yielded the dihydrofuro-[2,3-b]quinolines, identified as 2-(1-hydroxy-1-methylethyl-4-methoxy-2,3-dihydrofuro[2,3-b]quinoline (5) (racemic platydesmine) and 2-(1-hydroxy-1-methylethyl)-4,6,8-trimethoxy-2,3-dihydrofuro-[2,3-b]quinoline (6) (racemic precursor of O4-methylptelefolonium salt). 相似文献
15.
Palustridine (I, C18H31N3O3), which co-occurs with palustrine in Equisetum palustre L., has been shown to be Nb-formyl-palustrine. Hydrolysis with dilute mineral acid yields palustrine, and formylation of the latter gives palustridine. The mass spectral fragmentation pattern differs from that of palustrine, and is very similar to that of Nb-acetylpalustrine. The earlier proposed skeleton of palustrine is independently confirmed. 相似文献
16.
Carlos A. Escobar Oscar Donoso‐Tauda Ramiro Araya‐Maturana Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o426-o430
The 1,5‐benzodiazepine ring system exhibits a puckered boat‐like conformation for all four title compounds [4‐(2‐hydroxyphenyl)‐2‐phenyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C21H18N2O, (I), 2‐(2,3‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (II), 2‐(3,4‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (III), and 2‐(2,5‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (IV)]. The stereochemical correlation of the two C6 aromatic groups with respect to the benzodiazepine ring system is pseudo‐equatorial–equatorial for compounds (I) (the phenyl group), (II) (the 2,3‐dimethoxyphenyl group) and (III) (the 3,4‐dimethoxyphenyl group), while for (IV) (the 2,5‐dimethoxyphenyl group) the system is pseudo‐axial–equatorial. An intramolecular hydrogen bond between the hydroxyl OH group and a benzodiazepine N atom is present for all four compounds and defines a six‐membered ring, whose geometry is constant across the series. Although the molecular structures are similar, the supramolecular packing is different; compounds (I) and (IV) form chains, while (II) forms dimeric units and (III) displays a layered structure. The packing seems to depend on at least two factors: (i) the nature of the atoms defining the hydrogen bond and (ii) the number of intermolecular interactions of the types O—H...O, N—H...O, N—H...π(arene) or C—H...π(arene). 相似文献
17.
Andrzej Okuniewski Damian Rosiak Jarosaw Chojnacki 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(5):468-475
By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6‐dimethyl‐2‐pyrimido(thio)nium salts, which were characterized by single‐crystal X‐ray diffraction, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bifluoride, C6H9N2O+·HF2? or (dmpH)F2H, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bromide, C6H9N2O+·Br? or (dmpH)Br, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide, C6H9N2O+·I? or (dmpH)I, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide–urea (1/1), C6H9N2O+·I?·CH4N2O or (dmpH)I·ur, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bifluoride–thiourea (1/1), C6H9N2S+·HF2?·CH4N2S or (dmptH)F2H·tu, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bromide, C6H9N2S+·Br? or (dmptH)Br, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium iodide, C6H9N2S+·I? or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium chloride, (dmpH)Cl, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride monohydrate, (dmptH)Cl·H2O, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride–thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one‐dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge‐assisted N+—H…X? hydrogen bonds, as well as weaker CAr+—H…X? and π+…X? interactions. The structures can be divided into five types according to their hydrogen‐bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150–300 °C) without melting. Four oxopyrimidinium salts containing a π+…X?…π+ sandwich‐like structural motif exhibit luminescent properties. 相似文献
18.
Mohammad Navid SoltaniRad Ali Khalafi‐Nezhad Somayeh Babamohammadi Somayeh Behrouz 《Helvetica chimica acta》2010,93(12):2454-2466
A convenient and efficient method for a one‐pot conversion of N‐alkylisatins to N‐alkylisatin O‐alkyloximes 7a – 7n as potential chemotherapeutic agents is described (Scheme) (isatin=1H‐indole‐2,3‐dione). In this method, the microwave‐assisted three‐component reaction of N‐alkylisatins 8 , hydroxylamine hydrochloride, and diverse alkyl halides in the presence of K2CO3 and Bu4NBr furnishes the corresponding N‐alkylisatin O‐alkyloximes under solvent‐free condition in short times (2–10 min) and good to excellent yields (62–83%). The O‐alkylation of in situ generated isatin oximes with alkyl halides was achieved regioselectively, and (Z)‐O‐alkyloximes were produced dominantly. PM3 Semi‐empirical quantum‐mechanic calculations were performed to rationalize the evidences, and the calculations indicated a lower heat of formation for the (Z)‐O‐alkyloximes. 相似文献
19.
Jorge Trilleras Jairo Quiroga Justo Cobo Michael B. Hursthouse Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):o134-o139
Molecules of 1,3‐dimethyl‐7‐(4‐methylphenyl)pyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C16H15N3O2, (I), are linked by paired C—H...O hydrogen bonds to form centrosymmetric R22(10) dimers, which are linked into chains by a single π–π stacking interaction. A single C—H...O hydrogen bond links the molecules of 7‐(biphenyl‐4‐yl)‐1,3‐dimethylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C21H17N3O2, (II), into C(10) chains, which are weakly linked into sheets by a π–π stacking interaction. In 7‐(4‐fluorophenyl)‐3‐methylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C14H10FN3O2, (III), an N—H...O hydrogen bond links the molecules into C(6) chains, which are linked into sheets by a π–π stacking interaction. The molecules of 7‐(4‐methoxyphenyl)‐3‐methylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C15H13N3O3, (IV), are also linked into C(6) chains by an N—H...O hydrogen bond, but here the chains are linked into sheets by a combination of two independent C—H...π(arene) hydrogen bonds. 相似文献
20.
Sibrina N. Collins Stephen Taylor Jeanette A. Krause William B. Connick 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(10):m436-m439
1‐[6‐(1H‐Pyrrolo[2,3‐b]pyridin‐1‐yl)pyridin‐2‐yl]‐1H‐pyrrolo[2,3‐b]pyridin‐7‐ium tetrachloridoferrate(III), (C19H14N5)[FeCl4], (II), and [2,6‐bis(1H‐pyrrolo[2,3‐b]pyridin‐1‐yl‐κN7)pyridine‐κN]bis(nitrato‐κO)copper(II), [Cu(NO3)2(C19H13N5)], (III), were prepared by self‐assembly from FeCl3·6H2O or Cu(NO3)2·3H2O and 2,6‐bis(1H‐pyrrolo[2,3‐b]pyridin‐1‐yl)pyridine [commonly called 2,6‐bis(azaindole)pyridine, bap], C19H13N5, (I). Compound (I) crystallizes with Z′ = 2 in the P space group, with both independent molecules adopting a trans–trans conformation. Compound (II) is a salt complex with weak C—H...Cl interactions giving rise to a zigzag network with π‐stacking down the a axis. Complex (III) lies across a twofold rotation axis in the C2/c space group. The CuII center in (III) has an N3O2 trigonal–bipyramidal environment. The nitrate ligand coordinates in a monodentate fashion, while the bap ligand adopts a twisted tridentate binding mode. C—H...O interactions give rise to a ribbon motif. 相似文献