X-ray Crystal Structure of a Metalled Double-Helix Generated by Infinite and Consecutive C*-AgI -C* (C*:N1 -Hexylcytosine) Base Pairs through Argentophilic and Hydrogen Bond Interactions

2017 ◽  
Vol 23 (9) ◽  
pp. 2103-2108 ◽  
Author(s):  
Angel Terrón ◽  
Blas Moreno-Vachiano ◽  
Antonio Bauzá ◽  
Angel García-Raso ◽  
Juan Jesús Fiol ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Double Helix ◽  
Base Pairs ◽  
X Ray ◽  
Hydrogen Bond Interactions

scholarly journals Crystal structure of d(CCGGGGTACCCCGG)2at 1.4 Å resolution

2017 ◽  
Vol 73 (5) ◽  
pp. 259-265
Author(s):  
Selvam Karthik ◽  
Arunachalam Thirugnanasambandam ◽  
Pradeep Kumar Mandal ◽  
Namasivayam Gautham
Keyword(s):  
Crystal Structure ◽  
Metal Ion ◽  
Double Helix ◽  
Barium Chloride ◽  
Base Pairs ◽  
X Ray ◽  
Density Map ◽  
Solvent Molecules ◽  
Electron Density Map ◽  
Phosphate Groups

The X-ray crystal structure of the DNA tetradecamer sequence d(CCGGGGTACCCCGG)2is reported at 1.4 Å resolution in the tetragonal space groupP41212. The sequence was designed to fold as a four-way junction. However, it forms an A-type double helix in the presence of barium chloride. The metal ion could not be identified in the electron-density map. The crystallographic asymmetric unit consists of one A-type double helix with 12 base pairs per turn, in contrast to 11 base pairs per turn for canonical A-DNA. A large number of solvent molecules have been identified in both the grooves of the duplex and around the backbone phosphate groups.

Synthesis, Photophysics and Theoretical Calculation of (E)-2-(benzo[d] thiazol-2-yl)-3-(3-methoxyphenyl)acrylonitrile

2020 ◽  
Vol 17 (9) ◽  
pp. 688-693
Author(s):  
Pei-Chieh Wu ◽  
Chih-Hsien Chen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Emission Intensity ◽  
Intermolecular Hydrogen Bond ◽  
Aromatic Rings ◽  
Organic Nanoparticles ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
New Type ◽  
The Stability

In this study, a new type of luminogen with aggregation-induced-emission (AIE) behavior was designed and synthesized. The result of single-crystal X-ray structure showed a planar structure in which the dihedral angle between two aromatic rings is less than 30o. Moreover, two different intermolecular hydrogen bond interactions supported the stability of the crystal structure. After the formation of organic nanoparticles in poor solubility solvent, the emission intensity of the desired product was increased and the enhancement achieved was 14-fold. This new design of luminogen provided further understanding of the AIE mechanism.

A photodimer of a 4-phenyl-4H-pyran

2006 ◽  
Vol 62 (5) ◽  
pp. o1951-o1953 ◽  
Author(s):  
Hong Yan ◽  
Hui-Qin Wang ◽  
Cheng-Liang Ni ◽  
Xiu-Qing Song
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bond ◽  
Solid State ◽  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Hydrogen Bond Interactions

A new cage photodimer, tetraethyl 2,4,8,10-tetramethyl-6,12-diphenyl-3,9-dioxapentacyclo[6.4.0.02,7.04,11.05,10]dodecane-1,5,7,11-tetracarboxylate, C38H44O10, was prepared through [2+2]-photocycloaddition of diethyl 2,6-dimethyl-4-phenyl-4H-pyran-3,5-dicarboxylate in the solid state. The molecular structure was elucidated by X-ray diffraction analysis, 1H NMR, IR and mass spectroscopy, and elemental analysis. The molecule possesses a crystallographically imposed centre of symmetry. The crystal structure is stabilized by weak C—H...O hydrogen-bond interactions.

Crystal structure of ziprasidone hydrochloride monohydrate, C21H22Cl2N4OS(H2O)

2015 ◽  
Vol 30 (3) ◽  
pp. 192-198
Author(s):  
James A. Kaduk ◽  
Kai Zhong ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Density Functional ◽  
Minimum Energy ◽  
Strong Hydrogen Bond ◽  
Powder Diffraction File ◽  
X Ray ◽  
Hydrochloride Monohydrate ◽  
Positively Charged

The crystal structure of ziprasidone hydrochloride monohydrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Ziprasidone hydrochloride monohydrate crystallizes in space group P-1 (#2) with a = 7.250 10(3), b = 10.986 66(8), c = 14.071 87(14) Å, α = 83.4310(4), β = 80.5931(6), γ = 87.1437(6)°, V = 1098.00(1) Å3, and Z = 2. The ziprasidone conformation in the solid state is very close to the minimum energy conformation. The positively-charged nitrogen in the ziprasidone makes a strong hydrogen bond with the chloride anion. The water molecule makes two weaker bonds to the chloride, and acts as an acceptor in an N–H⋯O hydrogen bond. The powder pattern is included in the Powder Diffraction File™ as entry 00-064-1492.

The crystal structure of ethyl-Z-3-amino-2-benzoyl-2-butenoate and measurement of the barrier to E,Z-isomerization

1980 ◽  
Vol 58 (17) ◽  
pp. 1821-1828 ◽  
Author(s):  
Gary D. Fallon ◽  
Bryan M. Gatehouse ◽  
Allan Pring ◽  
Ian D. Rae ◽  
Josephine A. Weigold
Keyword(s):  
Crystal Structure ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bond ◽  
Free Energy ◽  
Magnetic Resonance ◽  
Energy Of Activation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Free Energy Of Activation ◽  
Nuclear Magnetic

Ethyl-3-amino-2-benzoyl-2-butenoate crystallizes from pentane as either the E (mp 82–84 °C) or the Z-isomer (mp 95.5–96.5 °C). The E isomer is less stable, and changes spontaneously into the Z, which bas been identified by X-ray crystallography. The structure is characterised by an N–H/ester CO hydrogen bond and a very long C2—C3 bond (1.39 Å). Nuclear magnetic resonance methods have been used to measure the rate of [Formula: see text] isomerization at several temperatures, leading to the estimate that the free energy of activation at 268 K is 56 ± 8 kJ.

scholarly journals Synthesis and Complexation Properties of 2-Hydroxy-5-methoxyphenylphosphonic Acid (H3L1). Crystal Structure of the [Cu(H2L1)2(Н2О)2] Complex

2021 ◽  
Vol 91 (11) ◽  
pp. 2176-2186
Author(s):  
G. S. Tsebrikova ◽  
Yu. I. Rogacheva ◽  
I. S. Ivanova ◽  
A. B. Ilyukhin ◽  
V. P. Soloviev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Methoxy Group ◽  
Protonation Constants ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Intramolecular Hydrogen ◽  
Oxygen Atoms

Abstract 2-Hydroxy-5-methoxyphenylphosphonic acid (H3L1) and the complex [Cu(H2L1)2(H2O)2] were synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. The polyhedron of the copper atom is an axially elongated square bipyramid with oxygen atoms of phenolic and of monodeprotonated phosphonic groups at the base and oxygen atoms of water molecules at the vertices. The protonation constants of the H3L1 acid and the stability constants of its Cu2+ complexes in water were determined by potentiometric titration. The protonation constants of the acid in water are significantly influenced by the intramolecular hydrogen bond and the methoxy group. The H3L1 acid forms complexes CuL‒ and CuL24‒ with Cu2+ in water.

Synthesis and X-ray diffraction analysis of the tetrazole peptide analogue Pro-LeuΨ[CN4]Gly-NH2

1988 ◽  
Vol 53 (11) ◽  
pp. 2863-2876 ◽  
Author(s):  
Giovanni Valle ◽  
Marco Crisma ◽  
Kuo-Long Yu ◽  
Claudio Toniolo ◽  
Ram K. Mishra ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Diffraction Analysis ◽  
Dopamine Receptor ◽  
Torsion Angle ◽  
Peptide Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conformationally Restricted ◽  
Bond Characteristic

The synthesis of an analogue of the neuropharmacologically active peptide Pro-Leu-Gly-NH2 in which the Leu-Gly peptide bond has been replaced with a tetrazole moiety was carried out. The molecular and crystal structure of the tetrazole analogue Pro-Leuψ[CN4]Gly-NH2 was determined by X-ray diffraction and a comparison was made with the published X-ray structure of Pro-Leu-Gly-NH2. The tetrazole annular system turns out to be a good conformationally-restricted replacement for the cis-peptide bond in terms of bond lengths, bond angles and the ω torsion angle. The molecule was found to be folded at the -Leuψ[CN4]Gly- sequence, but it did not form the intramolecular N-H···O=C hydrogen bond characteristic of the type Vla β-bend conformation. In contrast to Pro-Leu-Gly-NH2, Pro-Leuψ[CN4]Gly-NH2 was found to be unable to enhance the binding of dopamine receptor agonists to the dopamine receptor.

Crystal structure of methylprednisolone acetate form II, C24H32O6

2018 ◽  
Vol 33 (1) ◽  
pp. 44-48
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Density Functional ◽  
Hydroxyl Groups ◽  
Methylprednisolone Acetate ◽  
Powder Diffraction File ◽  
X Ray ◽  
Bond Network ◽  
Acetate Form

The crystal structure of methylprednisolone acetate form II, C24H32O6, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Methylprednisolone acetate crystallizes in space group P212121 (#19) with a = 8.17608(2), b = 9.67944(3), c = 26.35176(6) Å, V = 2085.474(6) Å3, and Z = 4. Both hydroxyl groups act as hydrogen bond donors, resulting in a two-dimensional hydrogen bond network in the ab plane. C–H⋯O hydrogen bonds also contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1412.

scholarly journals A Novel DR/NIR T-Shaped AIEgen: Synthesis and X-Ray Crystal Structure Study

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 269 ◽  
Author(s):  
Rosita Diana ◽  
Ugo Caruso ◽  
Luigi Di Costanzo ◽  
Gelsomina Bakayoko ◽  
Barbara Panunzi
Keyword(s):  
Crystal Structure ◽  
Near Infrared ◽  
Condensation Product ◽  
Infrared Emission ◽  
Structure Study ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
Main Plane ◽  
Donor Acceptor ◽  
Intramolecular Hydrogen

We developed a new benzodifuran derivative as the condensation product between 2,6-diamino-4-(4-nitrophenyl)benzo[1,2-b:4,5-b’]difuran-3,7-dicarboxylate and 3-hydroxy-2-naphthaldehyde. The intramolecular hydrogen-bond interactions in the terminal half-salen moieties produce a sterically encumbered highly conjugated main plane and a D-A-D (donor-acceptor-donor) T-shaped structure. The novel AIEgen (aggregation-induced enhanced emission generator) fulfils the requirement of RIR (restriction of intramolecular rotation) molecules. DR/NIR (deep red/near infrared) emission was recorded in solution and in the solid state, with a noteworthy photoluminescence quantum yield recorded on the neat crystals which undergo some mechanochromism. The crystal structure study of the probe from data collected at a synchrotron X-ray source shows a main aromatic plane π-stacked in a columnar arrangement.

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