Crystal Structure of N-Acetylkynurenine

1979 ◽  
Vol 32 (4) ◽  
pp. 911 ◽  
Author(s):  
CHL Kennard ◽  
Y Matsuura ◽  
N Tanaka ◽  
M Kakudo
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Direct Methods ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Amino Groups ◽  
Torsion Angles ◽  
Bonding System ◽  
Hydrogen Bonding System

The crystal structure of N-acetylkynurenine [o-NH2C6H4COCH2CH(COOH)NHCOCH3] was determined by direct methods. The crystals are monoclinic, a 11.200(2), b 9.708(1), c 11.451(1) �,β 90.16(2)�, space group P21, with Z 4. The structure was refined by least squares to R 0.033 with 1909 unique reflections, collected on an automated four-circle diffractometer. The structure is similar to the related L-trytophan hydrochloride. The two molecules in the asymmetric unit (A,B) are generally similar structurally but differ slightly in the conformation of the N-acetyl chain which has dihedral angles with the plane of the benzene ring of 78.0� (A) and 81.5� (B). Torsion angles about the C(α)-C(β) bond between C(γ) and both the carboxyl and the amino groups make them mutually gauche. There is an extensive hydrogen-bonding system between the two distinct molecules and between similar molecules either to form a dimer or a linear polymer.

scholarly journals The effect of hydrogen bonding on the conformations of 2-(1H-indol-3-yl)-2-oxoacetamide and 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide

2012 ◽  
Vol 68 (10) ◽  
pp. o405-o407 ◽  
Author(s):  
Vijayakumar N. Sonar ◽  
Sean Parkin ◽  
Peter A. Crooks
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Carbonyl Groups ◽  
Single Bond ◽  
Torsion Angles ◽  
Bonding System ◽  
Dimensional Network ◽  
Hydrogen Bonding System

In the title compounds, C10H8N2O2, (I), and C12H12N2O2, (II), the two carbonyl groups are oriented with torsion angles of −149.3 (3) and −88.55 (15)°, respectively. The single-bond distances linking the two carbonyl groups are 1.528 (4) and 1.5298 (17) Å, respectively. In (I), the molecules are linked by an elaborate system of N—H...O hydrogen bonds, which form adjacentR22(8) andR42(8) ring motifs to generate a ladder-like construct. Adjacent ladders are further linked by N—H...O hydrogen bonds to build a three-dimensional network. The hydrogen bonding in (II) is far simpler, consisting of helical chains of N—H...O-linked molecules that follow the 21screw of thebaxis. It is the presence of an elaborate hydrogen-bonding system in the crystal structure of (I) that leads to the different torsion angle for the orientation of the two adjacent carbonyl groups from that in (II).

The halotrichite group: the crystal structure of apjohnite

1976 ◽  
Vol 40 (314) ◽  
pp. 599-608 ◽  
Author(s):  
S. Menchetti ◽  
C. Sabelli
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Direct Methods ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Direct Connection ◽  
Asymmetric Unit ◽  
X Ray ◽  
Bonding System ◽  
Hydrogen Bonding System

SummaryApjohnite, MnAl2(SO4)4·22H2O, is monoclinic, space group P21/c, a 6·198 (2), b 24·347 (4), c 21·266 (4) Å, β 100·28 (3)° and Z = 4. The crystal structure was determined by means of direct methods applied to X-ray data collected with a single-crystal diffractometer. At the end of the refinement, performed with least-squares method, the R index was 0·039.The SO4 tetrahedra, Al(H2O)5 octahedra, and MnO(H2O)5 octahedra are connected by a hydrogen bonding system; the only direct connection between polyhedra is by sharing of an oxygen between S(4) and Mn. In the asymmetric unit there are twenty-two water molecules, five of which lie in channels of the structure and are not linked to the cations but only to ligand water oxygens by means of hydrogen bonds.Powder data indicate a close structural relationship between apjohnite, halotrichite, and pickeringite.

Ethylenediammonium thiophene-2,5-dicarboxylate dihydrate, an acid–base complex with a three-dimensional hydrogen-bonding system

2006 ◽  
Vol 62 (7) ◽  
pp. o2951-o2952 ◽  
Author(s):  
Si-Min Wu ◽  
Ming Li ◽  
Jiang-Feng Xiang ◽  
Liang-Jie Yuan ◽  
Ju-Tang Sun
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Water Molecules ◽  
Inversion Center ◽  
Acid Base ◽  
Special Position ◽  
Compound C ◽  
Bonding System ◽  
Hydrogen Bonding System

The crystal structure of the title compound, C2H10N2 2+·C6H2O4S2−·2H2O, is built of ethylenediammonium dications, occupying a special position on an inversion center, thiophene-2,5-dicarboxylate dianions, in a special position on the twofold axis, and water molecules in general positions. All residues are involved in an extensive hydrogen-bonding system, which links them into a three-dimensional supramolecular arrangement.

Crystal structure of cis-Tetracarbonylbis(chloromercury)iron

1976 ◽  
Vol 29 (9) ◽  
pp. 1905 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
SB Wild
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Data ◽  
Title Compound ◽  
Direct Methods ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound has been determined by direct methods from X-ray diffraction data and refined by least squares to a residual of 0.071 for 2647 'observed' reflections. Crystals are monoclinic, C2/c, a = 36.81(1), b = 11.181(2), c = 20.369(5) �, β = 95.28(3)�, Z = 32. There are four independent molecules in the asymmetric unit, all with the cis disposition of ligands (<Fe-Hg), 2.498 �; <Hg-Fe-Hg), 80.9�); in one of the molecules one of the carbonyl sites is occupied by a more substantial moiety, possibly a result of partial occupancy of HgCl as a result of disorder or decomposition.

scholarly journals Crystal structure of 5-(1,3-dithian-2-yl)-2H-1,3-benzodioxole

2015 ◽  
Vol 71 (3) ◽  
pp. o167-o168
Author(s):  
Julio Zukerman-Schpector ◽  
Ignez Caracelli ◽  
Hélio A. Stefani ◽  
Olga Gozhina ◽  
Edward R. T. Tiekink
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Benzene Ring ◽  
Title Compound ◽  
Chair Conformation ◽  
Dihedral Angles ◽  
Equatorial Position ◽  
Asymmetric Unit ◽  
Compound C ◽  
The Difference

In the title compound, C11H12O2S2, two independent but virtually superimposable molecules,AandB, comprise the asymmetric unit. In each molecule, the 1,3-dithiane ring has a chair conformation with the 1,4-disposed C atoms being above and below the plane through the remaining four atoms. The substituted benzene ring occupies an equatorial position in each case and forms dihedral angles of 85.62 (9) (moleculeA) and 85.69 (8)° (moleculeB) with the least-squares plane through the 1,3-dithiane ring. The difference between the molecules rests in the conformation of the five-membered 1,3-dioxole ring which is an envelope in moleculeA(the methylene C atom is the flap) and almost planar in moleculeB(r.m.s. deviation = 0.046 Å). In the crystal, molecules ofAself-associate into supramolecular zigzag chains (generated by glide symmetry along thecaxis)viamethylene C—H...π interactions. Molecules ofBform similar chains. The chains pack with no specific directional intermolecular interactions between them.

scholarly journals Crystal structure of 3-benzamido-1-(4-nitrobenzyl)quinolinium trifluoromethanesulfonate

2016 ◽  
Vol 72 (5) ◽  
pp. 747-750
Author(s):  
Mariana Nicolas-Gomez ◽  
Iván J. Bazany-Rodríguez ◽  
Eduardo Plata-Vargas ◽  
Simón Hernández-Ortega ◽  
Alejandro Dorazco-González
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Organic Cations ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Group Interactions ◽  
Compound C ◽  
Hydrogen Bonding Interactions ◽  
Phenyl Rings ◽  
Supramolecular Chains

In the title compound, C23H18N3O3+·CF3SO3−, the asymmetric unit contains two crystallographically independent organic cations with similar conformations. Each cation shows a moderate distortion between the planes of the amide groups and the quinolinium rings with dihedral angles of 14.90 (2) and 31.66 (2)°. The quinolinium and phenyl rings are slightly twisted with respect to each other at dihedral angles of 6.99 (4) and 8.54 (4)°. The trifluoromethanesulfonate anions are linked to the organic cationsviaN—H...O hydrogen-bonding interactions involving the NH amide groups. In the crystal, the organic cations are linked by weak C—H...O(nitro group) interactions into supramolecular chains propagating along theb-axis direction.

scholarly journals 5,11,17,23-Tetra-tert-butyl-25,27-bis[2-(4-nitrophenoxy)ethoxy]calix[4]arene-26,28-diol acetonitrile tetrasolvate

2009 ◽  
Vol 65 (6) ◽  
pp. o1336-o1337
Author(s):  
Jiu-Mao Yuan ◽  
Yong-Hong Gao ◽  
Jian-Ping Ma ◽  
Dian-Shun Guo
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Cone Conformation ◽  
Compound C ◽  
Butyl Group ◽  
Benzene Rings ◽  
The Mean ◽  
Solvent Molecules

In the crystal structure of the title compound, C60H70N2O10·4CH3CN, the calix[4]arene molecule adopts an open-cone conformation with two intramolecular O—H...O hydrogen bonds. The four benzene rings of the calix[4]arene are twisted to the mean plane defined by four methylene C atoms bridging the benzene rings, with dihedral angles ranging from 57.74 (10) to 65.99 (12)°. Two pendant nitrophenyl rings are nearly perpendicular to each other, the dihedral angle being 70.9 (3)°. The asymmetric unit of the crystal structure contains four acetonitrile solvent molecules, one of which lies in the calix cavity and makes C—H...π interactions and another links with the calix[4]areneviaC—H...O hydrogen bonding. Onetert-butyl group is disordered over two sets of sites, with a 0.736 (13):0.264 (13) occupancy ratio.

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