scholarly journals Crystal structure analysis and supramolecular association in ethyl N-[amino(iminio)methyl]carbamate dichloride hemi-hydrate

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christiana Bamigboye ◽  
Hanna S. Abbo ◽  
Huey Chong Kwong ◽  
Sang Loon Tan ◽  
Edward R.T. Tiekink ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Molecular Electrostatic Potential ◽  
Positive Charge ◽  
Crystal Structure Analysis ◽  
Relative Orientation ◽  
Asymmetric Unit ◽  
Trans Conformation ◽  
Crystal Water ◽  
X Ray ◽  
X Ray Crystallography

Abstract X-ray crystallography on [EtOC(=O)N(H)C(=N+H2)NH2]Cl·½H2O (1) shows the asymmetric unit to comprise two independent cations, two chloride anions and crystal water. The main conformational difference between the cations is seen in the relative orientation of the ethyl groups; geometry-optimisation confirms the all-trans conformation is the most stable. The remaining parts of the cations are co-planar and feature intramolecular N–H···O(carbonyl) hydrogen bonds. An analysis of the C–N bonds suggests substantial delocalisation of the positive charge over the CN3 atoms. In the crystal, columns comprising the first independent cation are surrounded by four columns of the second cation within a network of water-O–H···Cl, N–H···Cl and N–H···O(water, carbonyl) hydrogen bonds, many of which are charge-assisted. The packing has been further investigated by Hirshfeld surface analysis, molecular electrostatic potential and interaction energy calculations. The charge-assisted N–H···Cl hydrogen bonds are significantly stronger than the water-O–H···Cl interactions consistent the distribution of the positive charge over the CN3 atoms.

Synthesis and structural study of five new phosphoric triamides: interplay between classical and non-classical intermolecular interactions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bahar Bakhshipour ◽  
Atekeh Tarahhomi ◽  
Arie van der Lee
Keyword(s):  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Phosphoric Triamide ◽  
Ft Ir ◽  
Phosphoric Triamides

Abstract Phosphoric triamides are attractive to investigate because of their extensive applications in various fields, especially in medicine. Five new phosphoric triamides with the main parts [N]P(O)[NH]2 and [C(O)NH]P(O)[N]2 have been structurally analyzed by single crystal MoKα/synchrotron-based X-ray diffraction and characterized by spectroscopic methods (FT-IR and 1H, 13C, 31P NMR). Compounds crystallize in orthorhombic (1 with space group Pnma) and monoclinic (2 (P21/a), 3 (C2/c), 4 (P21/n) and 5 (P21/c)) crystal systems. The asymmetric unit of all structures consists of one phosphoric triamide molecule, except for 1 with one half of molecule. X-ray crystallography data reveal that the molecular architectures constructed by classical N—H … O hydrogen bonds are as 1D linear (building the R 2 1 ( 6 ) ${R}\_{2}^{1}(6)$ , C(4) and R 2 2 ( 10 ) / R 2 1 ( 6 ) ${R}\_{2}^{2}(10)/{R}\_{2}^{1}(6)$ motifs, respectively, for 1–3) or dimeric (the R 2 2 ( 8 ) ${R}\_{2}^{2}(8)$ ring motif for 4 and 5). A detailed investigation of the intermolecular interactions using Hirshfeld surface (HS) analysis illustrates that the H … H, O … H/H … O and C … H/H … C contacts for all compounds, and Cl … H/H … Cl and F … H/H … F contacts for 3–5, are the most significant contributors to the crystal packing. Moreover, based on the calculated enrichment ratios (E), the O … H/H … O contacts including the classical N—H … O hydrogen bonds for all structures are considered as favoured contacts.

scholarly journals Powder study of 3-azabicyclo[3.3.1]nonane-2,4-dione form 2

2006 ◽  
Vol 62 (7) ◽  
pp. o3046-o3048 ◽  
Author(s):  
Ashley T Hulme ◽  
Philippe Fernandes ◽  
Alastair Florence ◽  
Andrea Johnston ◽  
Kenneth Shankland
Keyword(s):  
Crystal Structure ◽  
Simulated Annealing ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Title Compound ◽  
Variable Temperature ◽  
Polycrystalline Sample ◽  
Asymmetric Unit ◽  
X Ray ◽  
Compound C

A polycrystalline sample of a new polymorph of the title compound, C8H11NO2, was produced during a variable-temperature X-ray powder diffraction study. The crystal structure was solved at 1.67 Å resolution by simulated annealing from laboratory powder data collected at 250 K. Subsequent Rietveld refinement yielded an R wp of 0.070 to 1.54 Å resolution. The structure contains two molecules in the asymmetric unit, which form a C 2 2(8) chain motif via N—H...O hydrogen bonds.

C−H- - -O Hydrogen Bonds in β-Sheetlike Networks:  Combined X-ray Crystallography and High-Pressure Infrared Study

2003 ◽  
Vol 125 (40) ◽  
pp. 12358-12364 ◽  
Author(s):  
Kwang Ming Lee ◽  
Hai-Chou Chang ◽  
Jyh-Chiang Jiang ◽  
Jack C. C. Chen ◽  
Hsiang-En Kao ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrogen Bonds ◽  
Infrared Study ◽  
X Ray ◽  
X Ray Crystallography

Systhesis, Characterization and Spectroscopic Properties of (2E,6E)-2,6-Bis(2,3,4-tri-methoxy-benzylidene)cyclohexanone

2011 ◽  
Vol 396-398 ◽  
pp. 2338-2341
Author(s):  
Xing Chuan Wei ◽  
Zhi Li Liu ◽  
Kun Zhang ◽  
Zhi Yun Du ◽  
Xi Zheng
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Spectroscopic Properties ◽  
Spectral Studies ◽  
Double Bonds ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography

In this paper, (2E,6E)-2,6-Bis(2,3,4-tri-methoxy -benzylidene)cyclohexanone (omitted as tmbcho) (1) was obtained by the reaction of acetic acid, tetrahydrofuran, cyclohexanone and 2,3,4-tri-methoxy-benzaldehyde. Three non-classic hydrogen bonds were observed in the compound. X-ray crystallography shows that the crystal structure is stabilized by intermolecular C-H•••π interactions and it contains plenty of conjugated double bonds. The title compound was characterized by UV-vis and fluorescent spectral studies.

A Zinc(II)-Silver(I) Bimetallic Coordination Polymer Assembled Through Argentophilic and π-π Interactions, f[Zn(phen)2(H2O) {Ag(CN)2g][Ag(CN)2]·MeOH}n (phen=1,10-Phenanthroline)

2013 ◽  
Vol 68 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Muhammad Monim-ul-Mehbooba ◽  
Muhammad Ramzan ◽  
Tobias Rüffe ◽  
Heinrich Lang ◽  
Shafqat Naddem ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Ir Spectroscopy ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
3D Network ◽  
Argentophilic Interactions

A cyanido-bridged Zn(II)-Ag(I) bimetallic coordination polymer, {[Zn(phen)2(H2O){Ag(CN)2}] [Ag(CN)2]·MeOH}n (1), was prepared using ZnCl2, 1,10-phenanthroline (phen) and K[Ag(CN)2] and characterized by IR spectroscopy, thermal analysis and X-ray crystallography. The crystal structure of 1 consists of dinuclear [Zn(phen)2(H2O){Ag(CN)2}]+ cations, [Ag(CN)2]- anions and a methanol molecule. The non-coordinated [Ag(CN)2]- anions are linked to the [Zn(phen)2(H2O){Ag(CN)2}]+ complex cations through argentophilic interactions leading to the formation of chains. The chains are connected by hydrogen bonds and π-π interactions to give a 3D network.

Crystal Structures of Seven Terephthaldiamide Derivatives

2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Layer Structure ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
X Ray ◽  
Layer Structures ◽  
Structure Determinations ◽  
Independent Molecules

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.

scholarly journals 1-[N-Methyl-N-(Phenyl)amino]-3- (4-Methylphenyl)Thiourea

Molbank ◽  
10.3390/m1052 ◽  
2019 ◽  
Vol 2019 (1) ◽  
pp. M1052 ◽  
Author(s):  
Chien Yeo ◽  
Edward Tiekink
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Title Compound ◽  
Molecular Conformation ◽  
Phenyl Hydrazine ◽  
X Ray ◽  
X Ray Crystallography

The title compound, 1-[N-methyl-N-(phenyl)amino]-3-(4-methylphenyl)thiourea (1), was synthesized by the reaction of 1-methyl-1-phenyl hydrazine and 4-tolyl isothiocyanate, and was characterized by spectroscopy (1H and 13C{1H} NMR, IR, and UV), elemental analysis as well as by single crystal X-ray crystallography. In the solid state, the molecule exists as the thioamide tautomer and features an anti-disposition of the thioamide–N–H atoms; an intramolecular N–H⋯N hydrogen bond is noted. The molecular conformation resembles that of the letter L. In the molecular packing, thioamide-N1–H⋯S1(thione) hydrogen bonds lead to centrosymmetric eight-membered {⋯HNCS}2 synthons. The dimers are assembled into a supramolecular layer in the bc-plane by phenyl- and methyl-C–H⋯π(phenyl) interactions.

The achiral tetrapeptideZ-Aib-Aib-Aib-Gly-OtBu

2014 ◽  
Vol 70 (11) ◽  
pp. 1046-1049 ◽  
Author(s):  
Renate Gessmann ◽  
Hans Brückner ◽  
Kyriacos Petratos
Keyword(s):  
Hydrogen Bonds ◽  
Butyl Ester ◽  
Relative Orientation ◽  
Asymmetric Unit ◽  
Intramolecular Hydrogen Bonds ◽  
Aminoisobutyric Acid ◽  
C Terminus ◽  
Intramolecular Hydrogen

The title achiral peptideN-benzyloxycarbonyl-α-aminoisobutyryl-α-aminoisobutyryl-α-aminoisobutyrylglycinetert-butyl ester orZ-Aib-Aib-Aib-Gly-OtBu (Aib is α-aminoisobutyric acid,Zis benzyloxycarbonyl, Gly is glycine and OtBu indicates thetert-butyl ester), C26H40N4O7, is partly hydrated (0.075H2O) and has two different conformations which together constitute the asymmetric unit. Both molecules form incipient 310-helices. They differ in the relative orientation of the N-terminal protection group and at the C-terminus. There are two 4→1 intramolecular hydrogen bonds.

scholarly journals Diosgenone: a secondP21polymorph

2012 ◽  
Vol 68 (8) ◽  
pp. o2358-o2358 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Gabriel Guerrero-Luna ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
María A. Fernández-Herrera
Keyword(s):  
Relative Orientation ◽  
Asymmetric Unit ◽  
Space Group ◽  
X Ray ◽  
Therapeutic Alternative ◽  
Structure Report ◽  
Independent Molecules

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been proposed as a new therapeutic alternative for the treatment of malaria. The first X-ray structure report for diosgenone was by Piroet al.[(2002).Z. Naturforsch. Teil C,57, 947–950] in the space groupP21(Z′ = 2). We now report a new polymorph in the same space group, with two molecules in the asymmetric unit. Both molecules have similar conformations, characterized by a skewed envelopeAring, which contains the C=C bond conjugated with the ketone functionality at C3. The dimorphism results from a modification of the relative orientation of the molecules in the asymmetric unit: two independent molecules were arranged antiparallel in the Piro report, while they are parallel in the present determination.

3(5),4-Dimethyl- and 3,4,5-trimethylpyrazole at 200 K. X-ray crystallography and quantum-chemical analysis

1999 ◽  
Vol 55 (3) ◽  
pp. 441-447 ◽  
Author(s):  
Lourdes Infantes ◽  
Concepción Foces-Foces ◽  
Jose Elguero
Keyword(s):  
Quantum Chemical ◽  
Molecular Structures ◽  
Asymmetric Unit ◽  
Quantum Chemical Analysis ◽  
X Ray ◽  
X Ray Crystallography ◽  
Crystal And Molecular Structures ◽  
Unit Form ◽  
Proton Disorder ◽  
Independent Molecules

The crystal and molecular structures of 3(5),4-dimethylpyrazole, C5H8N2, (I), and of 3,4,5-trimethylpyrazole, C6H10N2, (II), have been determined at 200 K. In (I) the 4,5-dimethylpyrazole tautomer is present in the solid state and the six independent molecules in the asymmetric unit form trimers via NH...N hydrogen bonds related by a pseudo centre of symmetry. The asymmetric unit of (II) contains one and a half molecules: these exhibit NH proton disorder and are hydrogen bonded to each other via their respective NH groups to form chains. Ab initio calculations at HF and B3LYP/6-31G** levels indicate that the 3,4-dimethylpyrazole tautomer is more stable than the 4,5-dimethylpyrazole tautomer by only approximately 0.5  kcal  mol−1 (1 kcal mol−1 = 4.184 kJ mol−1).

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