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1.
Xiaohua Peng Frank Seela Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o96-o98
In the title compound [systematic name: 7‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐2‐fluoro‐7H‐pyrrolo[2,3‐d]pyrimidin‐2‐amine], C11H13FN4O3, the conformation of the N‐glycosylic bond is between anti and high‐anti [χ = −110.2 (3)°]. The 2′‐deoxyribofuranosyl unit adopts the N‐type sugar pucker (4T3), with P = 40.3° and τm = 39.2°. The orientation of the exocyclic C4′—C5′ bond is −ap (trans), with a torsion angle γ = −168.39 (18)°. The nucleobases are arranged head‐to‐head. The crystal structure is stabilized by four intermolecular hydrogen bonds of types N—H⋯N, N—H⋯O and O—H⋯O. 相似文献
2.
Xiaohua Peng Hans Reuter Henning Eickmeier Frank Seela 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):o593-o595
In 4‐chloro‐7‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐7H‐pyrrolo[2,3‐d]pyrimidine‐2,4‐diamine, C11H14ClN5O3, the conformation of the N‐glycosylic bond is between anti and high‐anti [χ = −102.5 (6)°]. The 2′‐deoxyribofuranosyl unit adopts the C3′‐endo‐C4′‐exo (3T4) sugar pucker (N‐type) with P = 19.6° and τm = 32.9° [terminology: Saenger (1989). Landolt‐Börnstein New Series, Vol. 1, Nucleic Acids, Subvol. a, edited by O. Madelung, pp. 1–21. Berlin: Springer‐Verlag]. The orientation of the exocyclic C4′—C5′ bond is +ap (trans) with a torsion angle γ = 171.5 (4)°. The compound forms a three‐dimensional network that is stabilized by four intermolecular hydrogen bonds (N—H⋯O and O—H⋯N) and one intramolecular hydrogen bond (N—H⋯Cl). 相似文献
3.
Simone Budow Khalil I. Shaikh Henning Eickmeier Frank Seela 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o246-o248
In the title compound, 2′‐deoxy‐7‐propynyl‐7‐deazaadenosine, C14H16N4O3, the torsion angle of the N‐glycosylic bond is anti [χ = −130.7 (2)°]. The sugar pucker of the 2′‐deoxyribofuranosyl moiety is C2′‐endo–C3′‐exo, 2T3 (S‐type), with P = 185.9 (2)° and τm = 39.1 (1)°, and the orientation of the exocyclic C4′—C5′ bond is −ap (trans). The 7‐substituted propynyl group is nearly coplanar with the heterocyclic base moiety. Molecules of the nucleoside form a layered network in which the heterocyclic bases are stacked head‐to‐tail with a closest distance of 3.197 (1) Å. The crystal structure of the nucleoside is stabilized by three intermolecular hydrogen bonds of types N—H⋯ O, O—H⋯ N and O—H⋯ O. 相似文献
4.
Frank Seela Simone Budow Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(1):o54-o57
The title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythropentofuranosyl)‐5‐(prop‐1‐ynyl)pyrimidin‐2(1H)‐one, C12H15N3O4, shows two conformations in the crystalline state which differ mainly in the glycosylic bond torsion angle and the sugar pucker. Both molecules exhibit an anti glycosylic bond conformation, with torsion angles χ = −135.0 (2) and −156.4 (2)° for molecules 1 and 2, respectively. The sugar moieties show a twisted C2′‐endo sugar pucker (S‐type), with P = 173.3 and 192.5° for molecules 1 and 2, respectively. The crystal structure is characterized by a three‐dimensional network that is stabilized by several intermolecular hydrogen bonds between the two conformers. 相似文献
5.
Frank Seela Khalil I. Shaikh Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o151-o153
In the title compound, 2‐amino‐7‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐3,7‐dihydropyrrolo[2,3‐d]pyrimidin‐4‐one, C11H14N4O4, the N‐glycosylic bond torsion angle, χ, is anti [−106.5 (3)°]. The 2′‐deoxyribofuranosyl moiety adopts the 3T4 (N‐type) conformation, with P = 39.1° and τm = 40.3°. The conformation around the exocyclic C—C bond is ap (trans), with a torsion angle, γ, of −173.8 (3)°. The nucleoside forms a hydrogen‐bonded network, leading to a close‐packed multiple‐layer structure with a head‐to‐head arrangement of the bases. The nucleobase interplanar O=C—C⋯NH2 distance is 3.441 (1) Å. 相似文献
6.
Frank Seela Khalil Shaikh Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o489-o491
The title compound, C14H16N4O4, adopts the anti conformation at the glycosylic bond [χ−117.1 (5)°]. The sugar pucker of the 2′‐deoxyribofuranosyl moiety is C2′‐endo–C3′‐exo, 2T3 (S‐type). The orientation of the exocyclic C4′—C5′ bond is +sc (gauche). The propynyl group is linear and coplanar with the nucleobase moiety. The structure of the compound is stabilized by several hydrogen bonds (N—H⋯O and O—H⋯O), leading to the formation of a multi‐layered network. The nucleobases, as well as the propynyl groups, are stacked. This stacking might cause the extraordinary stability of DNA duplexes containing this compound. 相似文献
7.
Frank Seela Xiaohua Peng Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o94-o97
The structures of the isomeric nucleosides 4‐nitro‐1‐(β‐d ‐ribofuranosyl)‐1H‐indazole, C12H13N3O6, (I), and 4‐nitro‐2‐(β‐d ‐ribofuranosyl)‐2H‐indazole, C12H13N3O6, (II), have been determined. For compound (I), the conformation of the glycosylic bond is anti [χ = −93.6 (6)°] and the sugar puckering is C2′‐exo–C3′‐endo. Compound (II) shows two conformations in the crystalline state which differ mainly in the sugar pucker; type 1 adopts the C2′‐endo–C3′‐exo sugar puckering associated with a syn base orientation [χ = 43.7 (6)°] and type 2 shows C2′‐exo–C3′‐endo sugar puckering accompanied by a somewhat different syn base orientation [χ = 13.8 (6)°]. 相似文献
8.
Xiaomei Zhang Simone Budow Peter Leonard Henning Eickmeier Frank Seela 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):o79-o81
In the title compound, 4‐amino‐2‐(2‐O‐methyl‐β‐d ‐ribofuranosyl)‐2H‐pyrazolo[3,4‐d]pyrimidine monohydrate, C11H15N5O4·H2O, the conformation of the N‐glycosylic bond is syn [χ = 20.1 (2)°]. The ribofuranose moiety shows a C3′‐endo (3T2) sugar puckering (N‐type sugar), and the conformation at the exocyclic C4′—C5′ bond is −ap (trans). The nucleobases are stacked head‐to‐head. The three‐dimensional packing of the crystal structure is stabilized by hydrogen bonds between the 2′‐O‐methylribonucleosides and the solvent molecules. 相似文献
9.
Frank Seela Padmaja Chittepu Junlin He Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o884-o886
In the title compound, 2‐(2‐deoxy‐2‐fluoro‐β‐d ‐arabinofuranosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione, C8H10FN3O5, the torsion angle of the N‐glycosylic bond is anti [χ = −125.37 (13)°]. The furanose moiety adopts the N‐type sugar pucker (3T2), with P = 359.2° and τm = 31.4°. The conformation around the C4′—C5′ bond is antiperiplanar (trans), with a torsion angle γ of 177.00 (11)°. A network is formed via hydrogen bonds from the nucleobases to the sugar residues, as well as through hydrogen bonds between the sugar moieties. 相似文献
10.
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
11.
Frank Seela Helmut Rosemeyer Alexander Melenewski Eva‐Maria Heithoff Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o142-o144
In the monohydrate of 2‐amino‐8‐(2‐deoxy‐α‐d ‐erythro‐pentofuranosyl)‐8H‐imidazo[1,2‐a][1,3,5]triazin‐4‐one, C10H13N5O4·H2O, denoted (I) or αZd, the conformation of the N‐glycosylic bond is in the high‐anti range [χ = 87.5 (3)°]. The 2′‐deoxyribofuranose moiety adopts a C2′‐endo,C3′‐exo(2′T3′) sugar puckering (S‐type sugar) and the conformation at the C4′—C5′ bond is ?sc (trans). 相似文献
12.
Frank Seela Yang He Hans Reuter Eva‐Maria Heithoff 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):989-991
In the title compound, 2‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐5‐methylpyrimidin‐4(1H)‐one, C10H15N3O4, the conformation of the N‐glycosidic bond is syn and the 2‐deoxyribofuranose moiety adopts an unusual OT1 sugar pucker. The orientation of the exocyclic C4′—C5′ bond is +sc (+gauche). 相似文献
13.
Alan Hazell Christine J. McKenzie Jimmi Nielsen 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):859-860
The title compound, C9H9NS3, crystallizes with two molecules in the asymmetric unit. In both molecules, the dithiane‐2‐thione rings adopt a symmetric half‐boat conformation with the C atom opposite the C—Sthione bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half‐boat by 82.7 (2) and 84.5 (2)° in the two molecules, so that the N atom is trans to the axial C—H bond in both cases. 相似文献
14.
Narayan S. Hosmane Chong Zheng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):525-527
The title dimer, bis[1‐cyclopentadienyl‐2‐methyl‐1‐titana‐3‐trimethylsilyl‐2,3‐dicarba‐closo‐hexaborane(6)], [Ti(C5H5)(C6H16B4Si)]2, reveals that the centrosymmetric molecule consists of two bent‐sandwich titanacarboranes bridged by the B—H—Ti bonds. The average bond distances are Ti—B 2.445 (3), Ti—C(cage) 2.334 (2) and Ti—C(Cp) 2.376 (3) Å, and the corresponding bond angles are Cp—Ti—Cp 163.2 (1) and Cp—Ti—Cb (Cb = C2B3 face) 139.9 (1)°; the Ti—H separations are 2.10 (2) and 2.19 (2) Å. 相似文献
15.
Frank Seela Anup M. Jawalekar Simone Budow Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(9):o562-o564
In the title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐6‐methylsulfanyl‐1H‐pyrazolo[3,4‐d]pyrimidine, C11H16N5O3S, the conformation of the glycosidic bond is between anti and high anti. The 2′‐deoxyribofuranosyl moiety adopts the C3′‐exo–C4′‐endo conformation (3T4, S‐type sugar pucker), and the conformation at the exocyclic C—C bond is +sc (+gauche). The exocyclic 6‐amine group and the 2‐methylsulfanyl group lie on different sides of the heterocyclic ring system. The molecules form a three‐dimensional hydrogen‐bonded network that is stabilized by O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds. 相似文献
16.
Jens Hartung Michaela Schwarz Ingrid Svoboda Hartmut Fuess 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o682-o684
The geometry of racemic methyl 2‐(4‐methyl‐2‐thioxo‐2,3‐dihydrothiazol‐3‐yloxy)propanoate, C8H11NO3S2, (I), is characterized by a distorted heterocyclic five‐membered ring and an enantiomorphic N‐alkoxy substituent, which is inclined at an angle of −68.8° to the thiazolethione plane in (M)‐(I). The unit cell consists of a 1:1 ratio of R,P‐ and S,M‐configured molecules of (I). The combination of a P configuration at the N—O axis and an R configuration at the asymmetric propanoate Cβ atom on one side, and an S,M configuration on the other side, is considered to originate from steric interactions. The largest substituent at the asymmetric propanoate Cβ atom, i.e. the methoxycarbonyl group, resides above the methyl substituent; the medium‐sized propanoate γ‐methyl substituent points in the opposite direction with respect to the N—O bond, whereas the H atom is located above the C=S double bond of the thiazolethione subunit. 相似文献
17.
Frank Seela Yang He Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o194-o196
In the title compound, 3‐amino‐2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐6‐methyl‐1,2,4‐triazin‐5(2H)‐one, C9H14N4O4, the conformation of the N‐glycosidic bond is high‐anti and the 2‐deoxyribofuranosyl moiety adopts a North sugar pucker (2T3). The orientation of the exocyclic C—C bond between the –CH2OH group and the five‐membered ring is ap (gauche, trans). The crystal packing is such that the nucleobases lie parallel to the ac plane; the planes are connected via hydrogen bonds involving the five‐membered ring. 相似文献
18.
Canan Kazak Veysel T. Yilmaz Suleyman Servi Murat Koca Frank W. Heinemann 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):o348-o350
The title compounds, 1,3‐dibenzoylimidazolidine‐2‐thione, C17H14N2O2S, (I), and 1,3‐dibenzoyl‐3,4,5,6‐tetrahydropyrimidine‐2(1H)‐thione, C18H16N2O2S, (II), were obtained from the reactions of imidazolidine‐2‐thione and 1,4,5,6‐tetrahydropyrimidine‐2‐thiol, respectively, with benzoyl chloride. Compounds (I) and (II) contain, respectively, imidazolidinethione [C=S = 1.6509 (14) Å] and pyrimidinethione [C=S = 1.6918 (19) Å] moieties bonded to two benzoyl rings. The molecules of (I) exhibit C2 symmetry, the C=S bond lying along the twofold rotation axis, while the molecules of (II) have mirror symmetry (Cs). The imidazolidine ring in (I) is essentially planar, while the pyrimidine ring in (II) adopts a boat conformation. Molecules of (I) are linked by weak intermolecular C—H⋯O interactions, while molecules of (II) are held together by van der Waals interactions. 相似文献
19.
Colm Crean John F. Gallagher Albert C. Pratt 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o36-o38
The title complex, C17H9N5·C6H4S4, contains π‐deficient bis(dinitrile) and TTF molecules stacked alternately in columns along the a‐axis direction; the interplanar angle between the TTF molecule and the isoindolinyl C4N[C(CN)2]2 moiety is 1.21 (4)°. The N‐allyl moiety in the TCPI molecule is oriented at an angle of 87.10 (10)° with respect to the five‐membered C4N ring, and the four C[triple‐bond]N bond lengths range from 1.134 (3) to 1.142 (3) Å, with C—C[triple‐bond]N angles in the range 174.3 (3)–176.9 (2)°. In the TTF system, the S—C bond lengths are 1.726 (3)–1.740 (3) and 1.751 (2)–1.763 (2) Å for the external S—C(H) and internal S—C(S) bonds, respectively. 相似文献
20.
Susim Maiti Monika Mukherjee Bidisha Nandi Madeleine Helliwell Nitya G. Kundu 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):992-994
The title compound, C26H21NO2S2, which consists of a benzothiazole skeleton with α‐naphthylvinyl and tosyl groups at positions 2 and 3, respectively, was prepared by palladium–copper‐catalyzed heteroannulation. The E configuration of the molecule about the vinyl C=C bond is established by the benzothiazole–naphthyl C—C—C—C torsion angle of 177.5 (4)°. The five‐membered heterocyclic ring adopts an envelope conformation with the Csp3 atom 0.380 (6) Å from the C2NS plane. The two S—C [1.751 (4) and 1.838 (4) Å] and two N—C [1.426 (5) and 1.482 (5) Å] bond lengths in the thiazole ring differ significantly. 相似文献