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1.
Jyoti Makker Sharmistha Dey Pravindra Kumar Tej P. Singh 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o212-o214
The title peptide N‐benzyloxycarbonyl–ΔLeu–l ‐Ala–l ‐Leu–OCH3 [methyl N‐(benzyloxycarbonyl)‐α,β‐dehydroleucyl‐l ‐alanyl‐l ‐leucinate], C24H35N3O6, was synthesized in the solution phase. The peptide adopts a type II′β‐turn conformation which is stabilized by an intramolecular 4 1 N—H?O hydrogen bond. The crystal packing is stabilized by two intermolecular N—H?O hydrogen bonds. 相似文献
2.
Nicolas Pradeille Anthony Linden Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o249-o252
The title compounds, O‐benzyl‐N‐(benzyloxycarbonyl)threonyl‐2,N‐dimethylalaninanilide, C30H35N3O5, and methyl (4R)‐4‐benzyloxy‐N‐(benzyloxycarbonyl)valyl‐2‐(methylalanyl)prolinate, C30H39N3O7, were obtained from the `azirine coupling' of the corresponding protected amino acids with 2,2,N‐trimethyl‐2H‐azirin‐3‐amine and methyl (4R)‐4‐(benzyloxy)‐N‐(2,2‐dimethyl‐2H‐azirin‐2‐yl)prolinate, respectively. The Aib unit in each molecule has the greatest turn‐ or helix‐inducing effect on the molecular conformation. Intermolecular N—H⋯O interactions link the molecules of the tripeptide into sheets and those of the dipeptide into extended chains. 相似文献
3.
R. Hema V. Parthasarathi S. Thamotharan S. Dubey D. P. Jindal 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o213-o215
In the title compound, 4‐(3β‐hydroxy‐17‐oxoandrost‐5‐en‐16‐ylidenemethyl)benzonitrile, C27H31NO2, rings A and C of the steroid nucleus are in chair conformations. The central six‐membered ring B is in an 8β,9α‐half‐chair conformation, while the five‐membered ring D adopts a 13β,14α‐half‐chair conformation. The cyanobenzylidene moiety has an E configuration with respect to the carbonyl group at position C17. The dihedral angle between the planes of the steroid nucleus and the cyanobenzylidene moiety is 22.61 (15)°. Intermolecular O—H⃛N hydrogen bonds formed between the hydroxyl group of the steroid and the N atom of the cyanobenzylidene moiety of symmetry‐related molecules link the steroid molecules into chains which run parallel to the b axis. 相似文献
4.
Henrik Birkedal Dieter Schwarzenbach Philip Pattison 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):975-977
The crystal structure of the neuroactive artificial dipeptide N‐benzyloxycarbonylprolyl‐d ‐leucine, C19H26N2O5, was solved using synchrotron radiation data collected on a very small crystal (20 × 20 × 380 μm). The molecules form hydrogen‐bonded 21 helices. The acid carbonyl group does not participate in strong hydrogen bonds. This is interpreted as a consequence of close‐packing requirements. 相似文献
5.
Renate Geßmann Norbert Schiemann Hans Brückner Kyriacos Petratos 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o413-o415
The intramolecular hydrogen‐bonding pattern of Z‐Leu‐Aib‐Pro‐Val‐OBg monohydrate [(N‐benzhydrylamino)carbonylmethyl N‐benzyloxycarbonyl‐α‐aminoisobutyrylprolylvalinate monohydrate], C43H55N5O8·H2O, is unusual for a tetrapeptide because, in addition to a 14 hydrogen bond, a second hydrogen bond of the type 15 is formed. This folding reflects the intramolecular hydrogen‐bonding pattern that this amino acid sequence adopts in the naturally occurring peptaibol alamethicin. 相似文献
6.
Daniel Fernndez Daniel Vega 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o661-o663
The title compound, C8H19NO7P2, is a member of the bisphosphonate family of therapeutic compounds. PHPBP has inner‐salt character, consisting of a negatively charged PO3 group and a positively charged N atom. The six‐membered piperidine ring adopts an almost‐perfect chair conformation. The hydroxyl group and the N atom have gauche and trans conformations in relation to the O—C—C—C—N backbone, respectively. Hydrogen bonding is the main contributor to the packing in the crystal, which consists of head‐to‐head dimers formed through phosphonyl–phosphonyl hydrogen bonds, while O—H⋯O and N—H⋯O interactions join the dimers into a plane parallel to crystallographic b and c axes. 相似文献
7.
Vladimir N. Nesterov 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(11):o806-o809
In the title compound 3,5‐bis(4‐methoxybenzylidene)‐1‐methyl‐4‐piperidone, C22H23NO3, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5‐bis(4‐methoxybenzylidene)‐1‐methyl‐4‐oxopiperidinium chloride, C22H24NO3+·Cl−, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both molecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H⋯O hydrogen bonds. In (II), cations and anions are linked by strong N—H⋯Cl hydrogen bonds, while weak C—H⋯O and C—H⋯Cl hydrogen bonds link the cations and anions into a three‐dimensional framework. 相似文献
8.
Daniel Fernndez Daniel Vega 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o228-o230
The title compound, 1‐hydroxy‐1‐phosphono‐3‐(1‐pyrrolidinio)propylidene‐1‐phosphonate, C7H17NO7P2, is a member of the bisphosphonate class of drugs. As a zwitterion, it possesses a negative charge on one of the PO3 groups and a positive charge on the pyrrolidine N atom. A zwitterion makes a contact with a neighbouring ion through the hydroxyl O atom and two phosphonyl O atoms, one each from two different PO3 groups. Hydrogen bonding involves O—H⋯O and N—H⋯O interactions; the former are involved in the formation of head‐to‐head dimers, while the latter join the dimers into a chain running along the crystallographic b axis. 相似文献
9.
16‐[3‐Methoxy‐4‐(2‐piperidin‐1‐ylethoxy)benzylidene]‐17‐oxoandrost‐5‐en‐3β‐yl acetate monohydrate
S. Thamotharan V. Parthasarathi Ranju Gupta Sheetal Guleria D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o727-o729
The title compound, C36H49NO5·H2O, has the outer two six‐membered rings of the steroid nucleus in chair conformations. The central ring B of the steroid nucleus is in an 8β,9α‐half‐chair conformation, while ring D of the steroid adopts a slightly distorted 13β,14α‐half‐chair conformation. The piperidine ring is in a chair conformation. The methoxybenzylidene moiety has an E configuration with respect to the carbonyl group at position 17. Intermolecular O—H?O and O—H?N hydrogen bonds link the steroid and water molecules into chains which run parallel to the b axis. 相似文献
10.
Lei He Hui‐Min Liu Xiao‐Lan Luo Wen‐Qin Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):o104-o106
The title compound, 2‐{N‐[2‐(2‐hydroxybenzamido)ethylammonioethyl]aminocarbonyl}phenolate, C18H21N3O4, crystallizes in a zwitterionic form as a result of intermolecular proton transfer and possesses a negatively charged phenolate group and a protonated amino group. The 2‐hydroxybenzamide and 2‐(aminocarbonyl)phenolate moieties attached to the two ends of the C—C—N—C—C backbone adopt a cis conformation in relation to this backbone. All N‐ and O‐bound H atoms are involved in hydrogen‐bond formation; the zwitterions are first linked into head‐to‐tail dimers, which are further organized into a two‐dimensional network parallel to the crystallographic bc plane. 相似文献
11.
Miroslav Zabadal Dominik Heger Marek Ne
as Petr Kln 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):o77-o79
The structures of the bichromophoric compounds N‐(1‐naphthylacetyl)glycine phenacyl ester, C22H19NO4, (I), and its oxygen analogue, phenacyl (1‐naphthylacetoxy)acetate, C22H18O5, (II), have been determined. The molecules of (I) are held together by intermolecular N—H⋯O hydrogen bonds between the carbonyl and N—H groups, while compound (II) does not show any hydrogen bonding in the crystal. 相似文献
12.
Jos Antnio Paixo Manuela Ramos Silva Ana Matos Beja Abílio J. F. N. Sobral Susana H. Lopes A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o721-o723
In the title compound, C15H17NO2, the ethoxycarbonyl group is anti with respect to the pyrrole N atom. The angle between the planes of the phenyl and pyrrole rings is 48.26 (9)°. The molecules are joined into dimeric units by a strong hydrogen bonds between pyrrole N—H groups and carbonyl O atoms. The geometry of the isolated molecule was studied by ab initio quantum mechanical calculations, employing both molecular orbital Hartree–Fock (MO–HF) and density functional theory (DFT) methods. The minimum energy was achieved for a conformation where the angle between the planes of the phenyl and pyrrole rings is larger, and that between the ethoxycarbonyl and pyrrole planes is smaller than in the solid‐state molecule. 相似文献
13.
K. C. Kumara Swamy Musa A. Said 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):491-492
In the molecular structure of the title compound, C6H14N+·C12H10O4P?, three O atoms are bonded to phosphorus. The oxygen connected to the biphenoxy residue is not involved in hydrogen bonding; of the other two, one oxygen is involved in intermolecular hydrogen bonding to an N—H group as well as the O—H group of the biphenoxy residue, while the second oxygen is involved in hydrogen bonding to two N—H groups. 相似文献
14.
Wojciech M. Wolf 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1112-1115
The conformations of the two approximately isomorphous structures 4′‐{[benzoyl(4‐chlorophenylhydrazono)methyl]sulfonyl}acetanilide, C22H18ClN3O4S, and 4′‐{[benzoyl(4‐methoxyphenylhydrazono)methyl]sulfonyl}acetanilide, C23H21N3O5S, are stabilized by resonance‐assisted intramolecular hydrogen bonds linking the hydrazone moieties and sulfonyl groups. The stronger bond is observed in the former compound. The difference in electronic properties between the Cl atom and the methoxy group is too small to significantly alter the non‐bonding interactions of the sulfonyl and β‐carbonyl groups. 相似文献
15.
Mustafa OdabasÛoglu igdem Albayrak Orhan Büyükgüngr Peter Lnnecke 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o616-o619
The title compounds, 2‐{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa‐3,5‐dien‐1(2H)‐one, C11H15NO4, (I), 6‐hydroxy‐2‐{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa‐3,5‐dien‐1(2H)‐one, C11H15NO5, (II), and 6‐methoxy‐2‐{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa‐3,5‐dien‐1(2H)‐one, C12H17NO5, (III), adopt the keto–amine tautomeric form, with the formal hydroxy H atom located on the N atom, and the NH group and oxo O atom display a strong intramolecular N—H⋯O hydrogen bond. The N—H⋯O hydrogen‐bonded rings are almost planar and coupled with the cyclohexadiene rings. The carbonyl O atoms accept two other H atoms from the alcohol groups of adjacent molecules in (I), and one from the alcohol and one from the phenol group in (II), but from only one alcohol H atom in (III). 相似文献
16.
Il Yoon Yong Woon Shin Jineun Kim Ki‐Min Park Sung Bae Park Shim Sung Lee 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):m165-m166
The synthesis and crystal structure of {tris[2‐(benzylamino)ethyl]amine‐κ4N}silver(I) perchlorate, [Ag(C27H36N4)]ClO4 or [Ag(bz3tren)]ClO4 {bz3tren is tris[2‐(benzylamino)ethyl]amine or N,N′,N′′‐tribenzyltris(2‐aminoethyl)amine} are reported. The Ag atom is coordinated to four N atoms of the tren unit and is located 0.604 (3) Å out of the trigonal plane described by the three secondary amine N atoms, away from the bridgehead N atom. Edge‐to‐face π–π interactions between the aromatic end groups, and weak interactions between Ag and arene, allow the formation of a pseudo‐cage complex. 相似文献
17.
Arthur Camerman Andrew Hempel Donald Mastropaolo Norman Camerman 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):o417-o419
In the crystal structure of 2‐acetamido‐N‐benzyl‐2‐(methoxyamino)acetamide (3L), C12H17N3O3, the 2‐acetylaminoacetamide moiety has a linearly extended conformation, with an interplanar angle between the two amide groups of 157.3 (1)°. In 2‐acetamido‐N‐benzyl‐2‐[methoxy(methyl)amino]acetamide (3N), C13H19N3O3, the planes of the two amide groups intersect at an angle of 126.4 (4)°, resulting in a chain that is slightly more bent. The replacement of the methoxyamino H atom of 3L with a methyl group to form 3N and concomitant loss of hydrogen bonding results in some positional/thermal disorder in the methoxy(methyl)amino group. In both structures, in addition to classical N—H⋯O hydrogen bonds, there are also weak non‐standard C—H⋯O hydrogen bonds. The hydrogen bonds and packing interactions result in planar hydrophilic and hydrophobic areas perpendicular to the c axis in 3L and parallel to the ab plane in the N‐methyl derivative. Stereochemical comparisons with phenytoin have identified two O atoms and a phenyl group as molecular features likely to be responsible for the anticonvulsant activities of these compounds. 相似文献
18.
Giuseppe Bruno Santo Lanza Francesco Nicol Giuseppe Tresoldi Giuseppe Rosace 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(10):o608-o609
The title compound, alternatively known as N,N′‐dibenzylethanedithioamide, C16H16N2S2, lies about an inversion centre and contains a planar trans‐dithiooxamide fragment characterized by a strong intramolecular hydrogen bond between the S atom and the adjacent amide H atom in the solid state, with an S?N distance of 2.926 (1) Å. The aryl substituent is oriented orthogonal to the mean plane of the trans‐dithiooxamide fragment due to steric hindrance and this effect is discussed. 相似文献
19.
Shyamaprosad Goswami Reshmi Mukherjee Kumaresh Ghosh Ibrahim Abdul Razak S. Shanmuga Sundara Raj Hoong‐Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):716-717
In the title compound, N‐(6‐chloro‐4‐oxo‐3,4‐dihydropteridin‐2‐yl)‐2,2‐dimethylpropanamide, C11H12ClN5O2, the rings in the pterin moiety are planar. The amide carbonyl O atom is in syn‐periplanar conformation while the C—N—C—C propanamide linkage is antiperiplanar. The N—H?N and N—H?O intermolecular hydrogen bonds transform the molecules into infinite chains. 相似文献
20.
Gordana Pavlovi Lidija Barii Vladimir Rapi Veronika Kova
《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):m55-m57
Heteroannularly substituted ferrocene derivatives can act as model systems for various hydrogen‐bonded assemblies of biomolecules formed, for instance, by means of O—H⋯O and N—H⋯O hydrogen bonding. The crystal structure analysis of 1′‐(tert‐butoxycarbonylamino)ferrocene‐1‐carboxylic acid, [Fe(C10H14NO2)(C6H5O2)] or (C5H4COOH)Fe(C5H4NHCOOC(CH3)3, reveals two independent molecules within the asymmetric unit, and these are joined into discrete dimers by two types of intermolecular hydrogen bonds, viz. O—H⋯O and N—H⋯O. The –COOH and –NHCOOR groups are archetypes for dimer formation via two eight‐membered rings. The O—H⋯O hydrogen bonds [2.656 (3) and 2.663 (3) Å] form a cyclic carboxylic acid dimer motif. Another eight‐membered ring is formed by N—H⋯O hydrogen bonds [2.827 (3) and 2.854 (3) Å] between the N—H group and an O atom of another carbamoyl moiety. The dimers are assembled in a herring‐bone fashion in the bc plane. 相似文献