共查询到20条相似文献,搜索用时 31 毫秒
1.
Kamlakar Avasthi Sheikh M. Farooq Diwan S. Rawat Ashoke Sharon Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):o523-o524
In the crystal structure of 1,3‐bis(4,6‐diisopropylsulfanyl‐1H‐pyrazolo[3,4‐d]pyrimidin‐1‐yl)propane, C25H36N8S4, the pairs of pyrazolo[3,4‐d]pyrimidine rings in the molecule stack as a result of intramolecular π–π interactions between the heterocyclic rings. The crystal packing also exhibits an intermolecular C—H...π interaction between one methyl group of an isopropyl group and a pyrazolo[3,4‐d]pyrimidine ring. 相似文献
2.
Intermolecular stacking in pyrazolo[3,4‐d]pyrimidine‐based pentamethylene‐linked flexible molecules
Kamlakar Avasthi Sheikh M. Farooq Ashish K. Tewari Ashoke Sharon Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o42-o45
The crystal structures of 1‐{5‐[4,6‐bis(methylsulfanyl)‐2H‐pyrazolo[3,4‐d]pyrimidin‐2‐yl]pentyl}‐6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C22H29N9S3, and 6‐methylsulfanyl‐1‐{5‐[6‐methylsulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo[3,4‐d]pyrimidin‐2‐yl]pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C25H34N10S2, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo[3,4‐d]pyrimidine rings. 相似文献
3.
Kamlakar Avasthi Sangeeta Aswal Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(11):1324-1325
In the crystal structure of 1,1′-(1,3-propanediyl)bis(5-ethyl-6-methylthio-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-4-one), C19H24N8O2S2, the pairs of pyrazolo[3,4-d]pyrimidine rings of the molecule stack between the heterocyclic rings, due to intramolecular π–π interactions. The substituted ethyl and methyl groups are comparable as far as intramolecular stacking is concerned. 相似文献
4.
Prakas R. Maulik Kamlakar Avasthi Sanjay Sarkhel Tilak Chandra Diwan S. Rawat Brad Logsdon Robert A. Jacobson 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1361-1363
In the crystal structures of 4,6‐dimethylthio‐1‐[3‐(4,6‐dimethylthio‐2H‐pyrazolo[3,4‐d]pyrimidin‐2‐yl)propyl]‐1H‐pyrazolo[3,4‐d]pyrimidine, C17H20N8S4, and 1‐[4‐(4‐methoxy‐6‐methylthio‐1H‐pyrazolo[3,4‐d]pyrimidin‐1‐yl)butyl]‐5‐methyl‐6‐methylthio‐4,5‐dihydro‐1H‐pyrazolo[3,4‐d]pyrimidin‐4‐one, C18H22N8O2S2, only intermolecular stacking due to aromatic π–π interactions between pyrazolo[3,4‐d]pyrimidinerings is present. 相似文献
5.
Kamlakar Avasthi Deepa Bhagat Chandralata Bal Ashoke Sharon Umesh Yadav Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o409-o412
The crystal structure of 4,6‐bis(methylsulfanyl)‐1‐phthalimidopropyl‐1H‐pyrazolo[3,4‐d]pyrimidine, C18H17N5O2S2, (VI), reveals an unusual folded conformation due to an apparent intramolecular C—H⃛π interaction between the 6‐methylsulfanyl and phenyl groups. However, the closely related compound 6‐methylsulfanyl‐1‐phthalimidopropyl‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C21H22N6O2S, (VII), exhibits a fully extended structure, devoid of any intramolecular C—H⃛π or π–π interactions. The crystal packing of both molecules involves intermolecular stacking interactions due to aromatic π–π interactions. In addition, (VI) exhibits intermolecular C—H⃛O hydrogen bonding and (VII) exhibits dimerization of the molecules through intermolecular C—H⃛N hydrogen bonding. 相似文献
6.
Junlin He Frank Seela Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(10):o593-o595
In the title regioisomeric nucleosides, alternatively called 1‐(2‐deoxy‐β‐d ‐erythro‐furanosyl)‐1H‐pyrazolo[3,4‐d]pyrimidine, C10H12N4O3, (II), and 2‐(2‐deoxy‐β‐d ‐erythro‐furanosyl)‐2H‐pyrazolo[3,4‐d]pyrimidine, C10H12N4O3, (III), the conformations of the glycosylic bonds are anti [?100.4 (2)° for (II) and 15.0 (2)° for (III)]. Both nucleosides adopt an S‐type sugar pucker, which is C2′‐endo‐C3′‐exo (2T3) for (II) and 3′‐exo (between 3E and 4T3) for (III). 相似文献
7.
Kamlakar Avasthi Diwan S. Rawat Sanjay Sarkhel Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):o325-o327
The title compound, 6‐methylsulfanyl‐1‐(3‐phenylpropyl)‐4,5‐dihydro‐1H‐pyrazolo[3,4‐d]pyrimidin‐4‐one, C15H16N4OS, crystallizes in space group Pbca, with two molecules of similar structure in the asymmetric unit. The molecular structure shows the absence of intramolecular stacking in the crystalline state, as indicated by earlier 1H NMR analysis in solution. In addition, the crystal packing reveals the formation of a layered structure, due mainly to intermolecular N—H?O=C hydrogen bonding and arene–arene interactions. 相似文献
8.
Frank Seela Yunlong Zhang Kuiying Xu Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):o60-o62
In the title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐eythro‐pentofuranosyl)‐3‐vinyl‐1H‐pyrazolo[3,4‐d]pyrimidine monohydrate, C12H15N5O3·H2O, the conformation of the glycosyl bond is anti. The furanose moiety is in an S conformation with an unsymmetrical twist, and the conformation at the exocyclic C—C(OH) bond is +sc (gauche, gauche). The vinyl side chain is bent out of the heterocyclic ring plane by 147.5 (5)°. The three‐dimensional packing is stabilized by O—H·O, O—H·N and N—H·O hydrogen bonds. 相似文献
9.
Sanjay Sarkhel Prativa Srivastava Vishnu J. Ram Prakas R. Maulik Charlotte K. Broder Judith A. K. Howard 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):e88-e89
The crystal structure of [2‐(4‐bromophenyl)‐4‐cyano‐5‐ferrocenylpyrazolo[2,3‐a]pyridin‐7‐yl]acetonitrile, C26H17N4FeBr or [Fe(C5H5)(C21H12BrN4)], shows that the pyrazolopyridine ring system (PP), the bromophenyl ring (BP) and the cyclopentadiene ring (Cp) are nearly planar. The PP ring system is twisted out of the plane of the BP and Cp rings by about 20°. 相似文献
10.
Raphaël Frdrick Bernadette Norberg Franois Durant Frederic Ooms Johan Wouters 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o623-o626
The structures of three compounds, namely 7‐methoxy‐2‐[3‐(trifluoromethyl)phenyl]‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C19H11F3N2O2, (Id), 6‐methoxy‐2‐[3‐(trifluoromethyl)phenyl]‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C19H11F3N2O2, (IId), and 2‐methyl‐6‐(4,4,4‐trifluorobutoxy)‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C16H13F3N2O2, (IIf), which are potent reversible type‐B monoamine oxidase (MAO‐B) inhibitors, are presented and discussed. Compounds (Id) and (IId) crystallize in a nearly planar conformation. The crystal structures are stabilized by weak C—H⋯O hydrogen bonds. The packing is dominated by π–π stacking interactions between the heterocyclic central moieties of centrosymmetrically related molecules. In compound (IIf), the trifluoroethyl termination is almost perpendicular to the plane of the ring. 相似文献
11.
John Nicolson Low Justo Cobo Manuel Nogueras Adolfo Snchez Harlen Torres Braulio Insuasty 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):o305-o310
The supramolecular structures of the title compounds, 2‐phenyl‐5‐p‐tolyl‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C23H21N3, (I), 5‐(4‐bromophenyl)‐2‐phenyl‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C22H18BrN3, (II), 2‐(4‐chlorophenyl)‐5‐phenyl‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C22H18ClN3, (III), and 5‐(4‐bromophenyl)‐2‐(4‐chlorophenyl)‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C22H17BrClN3, (IV), are of two general types. Compounds (I), (II) and (III) form base‐paired dimers via N—H?N hydrogen bonds, where (I) and (II) are isomorphous, while in (IV), there are no conventional hydrogen bonds. 相似文献
12.
John Nicolson Low Justo Cobo Braulio Insuasty Henry Insuasty Manuel Nogueras Adolfo Snchez 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o103-o105
In both title compounds, i.e. 3‐methyl‐1,5‐diphenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H18N4, (I), and 5‐(4‐chlorophenyl)‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H17ClN4, (II), an N—H?N hydrogen bond links six molecules to form an R(30) ring. Compound (I) crystallizes in the R space group and (II) crystallizes in P with three molecules in the asymmetric unit. The molecule of (I) contains a disordered seven‐membered ring. 相似文献
13.
Shi‐Ping Yang Xi‐Bin Yu Ji‐Guang Huang Han‐Hong Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):o392-o393
The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetrahydro‐8,9‐dimethoxy‐2‐(1‐methylethenyl)‐[1]benzopyrano[3,4‐b]furo[2,3‐h][1]benzopyran‐6(6H)‐one oxime], C23H23NO6, confirms that the molecule has an approximately V‐shaped structure. One of the rings has a typical cyclohexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation. 相似文献
14.
Jianping Zhao Ilias Muhammad D. Chuck Dunbar Ikhlas A. Khan Nikolaus H. Fischer Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o195-o198
A low‐temperature structure of ginkgolide A monohydrate, (1R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐dimethylethyl)‐hexahydro‐4,7b‐dihydroxy‐8‐methyl‐9H‐1,7a‐epoxymethano‐1H,6aH‐cyclopenta[c]furo[2,3‐b]furo[3′,2′:3,4]cyclopenta[1,2‐d]furan‐5,9,12(4H)‐trione monohydrate, C20H24O9·H2O, obtained from Mo Kα data, is a factor of three more precise than the previous room‐temperature determination. A refinement of the ginkgolide A monohydrate structure with Cu Kα data has allowed the assignment of the absolute configuration of the series of compounds. Ginkgolide C sesquihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11S,11aR)‐3‐(1,1‐dimethylethyl)‐hexahydro‐2,4,7b,11‐tetrahydroxy‐8‐methyl‐9H‐1,7a‐epoxymethano‐1H,6aH‐cyclopenta[c]furo[2,3‐b]furo[3′,2′:3,4]cyclopenta[1,2‐d]furan‐5,9,12(4H)‐trione sesquihydrate, C20H24O11·1.5H2O, has two independent diterpene molecules, both of which exhibit intramolecular hydrogen bonding between OH groups. Ginkgolide J dihydrate, (1S,2R,3S,3aS,4R,6aR,7aR,7bR,8S,10aS,11aS)‐3‐(1,1‐dimethylethyl)‐hexahydro‐2,4,7b‐trihydroxy‐8‐methyl‐9H‐1,7a‐epoxymethano‐1H,6aH‐cyclopenta[c]furo[2,3‐b]furo[3′,2′:3,4]cyclopenta[1,2‐d]furan‐5,9,12(4H)‐trione dihydrate, C20H24O10·2H2O, has the same basic skeleton as the other ginkgolides, with its three OH groups having the same configurations as those in ginkgolide C. The conformations of the six five‐membered rings are quite similar across ginkgolides A–C and J, except for the A and F rings of ginkgolide A. 相似文献
15.
Dmitry O. Ivashkevich Alexander S. Lyakhov Mikhail M. Degtyarik Pavel N. Gaponik 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):m368-m370
The title compound, {[CuCl2(PhTz)2]·0.5PhTz}n (PhTz is 1‐phenyltetrazole, C7H6N4), has a polymeric structure, with uncoordinated disordered PhTz molecules in the cavities. The coordination polyhedron of the Cu atom is a highly elongated octahedron. The equatorial positions are occupied by two Cl atoms [Cu—Cl = 2.2687 (9) and 2.2803 (7) Å] and two N atoms of the PhTz ligands [Cu—N = 2.0131 (19) and 2.0317 (18) Å]. The more distant axial positions are occupied by two Cl atoms [Cu—Cl = 3.0307 (12) and 2.8768 (11) Å] that lie in the equatorial planes of two neighbouring Cu octahedra. The [CuCl2(PhTz)2] units are linked by Cu—Cl bridges into infinite chains extending parallel to the a axis. The chains are linked into two‐dimensional networks by intermolecular C—H⋯N interactions between the phenyl and tetrazole fragments, and by face‐to‐face π–π interactions between symmetry‐related phenyl rings. These two‐dimensional networks, which lie parallel to the ac plane, are connected by intermolecular π–π stacking interactions between phenyl rings, thus forming a three‐dimensional network. 相似文献
16.
Chen‐Xin Cai Yun‐Qi Tian Yi‐Zhi Li Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):m459-m460
In the title mononuclear cobalt complex, bis(2,6‐dimethyl‐1H,7H‐benzo[1,2‐d:4,5‐d′]diimidazole‐κN3)bis(thiocyanato‐κN)cobalt(II), [CoII(NCS)2(DMBDIZ)2] or [Co(NCS)2(C10H10N4)2], the cobalt(II) ion is coordinated to four N atoms, from two thiocyanate anions and two DMBDIZ ligands, in a distorted tetrahedral geometry. In the DMBDIZ ligand, the two imine N atoms are positioned cis with respect to one another. The crystal packing of the complex is dominated by both hydrogen bonding, involving two N—H?N and two N—H?S interactions, and aromatic π–π stacking. 相似文献
17.
trans‐Diaquabis(5‐carboxy‐1H‐imidazole‐4‐carboxylato‐κ2N3,O4)cobalt(II) 4,4′‐bipyridine solvate
Rong Cao Yu‐Ling Wang Wen‐Hua Bi 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):m609-m611
In the title compound, [Co(C5H3N2O4)2(H2O)2]·C10H8N2, the Co atom is trans‐coordinated by two pairs of N and O atoms from two monoanionic 4,5‐dicarboxyimidazole ligands, and by two O atoms from two coordinated water molecules, in a distorted octahedral geometry. The 4,4′‐bipyridine solvent molecule is not involved in coordination but is linked by an N—H⋯N hydrogen bond to the neutral [Co(C5H3N2O4)2(H2O)2] molecule. Both molecules are located on inversion centers. The crystal packing is stabilized by N—H⋯N and O—H⋯O hydrogen bonds, which produce a three‐dimensional hydrogen‐bonded network. Offset π–π stacking interactions between the pyridine rings of adjacent 4,4′‐bipyridine molecules were observed, with a face‐to‐face distance of 3.345 (1) Å. 相似文献
18.
Philip J. Cox Marcel Jaspars Yashodharan Kumarasamy Lutfun Nahar Satyajit D. Sarker Mohammad Shoeb 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):o520-o522
The crystal structure of 9‐(3‐methylbut‐2‐enyloxy)‐7H‐furo[3,2‐g]chromen‐7‐one–4‐methoxy‐9‐(3‐methylbut‐2‐enyloxy)‐7H‐furo[3,2‐g]chromen‐7‐one (0.926/0.074), 0.926C16H14O4·0.074C17H16O5, is characterized by two independent imperatorin molecules in the asymmetric unit, which exhibit different side‐chain conformations. A small amount of phellopterin overlaps with one of the two imperatorin molecules. The supramolecular structure is supported by C—H...O, C—H...π and π–π interactions. 相似文献
19.
Wenqing Lin Frank Seela Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o566-o568
In the tricyclic nucleoside 7‐(β‐d ‐ribofuranosyl)‐7H‐imidazo[1,2‐c]pyrazolo[4,3‐e][1,2,3]triazine, C11H12N6O4, the conformation of the N‐glycosyl bond is intermediate between anti and high anti [χ = −103.5 (3)°]. The ribofuranose moiety adopts a 3T2 sugar pucker (S‐type sugar) and the conformation at the exocyclic C—C bond is ap (gauche–trans). Molecules of the title compound form a three‐dimensional network via three medium–strong intermolecular hydrogen bonds (one O—H⋯N and two O—H⋯O bonds). 相似文献
20.
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