β-Diketone interactions. Part 6. X-Ray molecular structure of 3-(4-methoxyphenyl)pentane-2,4-dione, a β-diketone enol tautomer with a very strong hydrogen bond

1988 ◽  
pp. 297-299 ◽  
Author(s):  
John Emsley ◽  
Neville J. Freeman ◽  
Paul A. Bates ◽  
Michael B. Hursthouseb
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Strong Hydrogen Bond ◽  
X Ray ◽  
Enol Tautomer

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.

Keto-Enol-Tautomerism and Configurational Isomerism of 2,6-Disubstituted 4-Piperidone-3,5-dicarboxylates

1991 ◽  
Vol 46 (9) ◽  
pp. 1237-1250 ◽  
Author(s):  
Ulrike Holzgrabe ◽  
Willy Friedrichsen ◽  
Karl-F. Hesse
Keyword(s):  
Hydrogen Bond ◽  
Alkyl Group ◽  
Semiempirical Calculations ◽  
Axial Position ◽  
Strong Hydrogen Bond ◽  
Spectroscopic Methods ◽  
X Ray ◽  
Characteristic Values ◽  
Configurational Isomerism

The dialkyl 2,6-dialkylsubstituted 4-piperidone-3,5-dicarboxylates were synthesized by a Mannich procedure. Depending on the substitution at the nitrogen keto-enol-tautomerism and a configurational isomerism at C 2 is observed. The structure of the N-substituted piperidone 24 E (C18H29NO5) has been determined by X-ray analysis: it is characterized by an enol structure of the β-ketoester and an axial position of the alkyl group at C 2 and an equatorial one of the alkyl group at C 6. The O–H···O hydrogen bond shows characteristic values of a strong hydrogen bond. The N-unsubstituted piperidones adopt a ketone structure with the allequatorial position of all substituents. This stereochemistry is confirmed for other enolic and ketone analogues by NMR spectroscopic methods. To work out the reason for the different thermodynamic stabilities of the different stereochemical structures of N-substituted and N-unsubstituted piperidones, various semiempirical calculations were done for series of simple pairs of carbonyl/enol tautomers, substituted acetoacetates, oxoglutarate as well as of systematically varied substituted cyclohexanone, 4-oxacyclohexanone and 4-piperidone derivatives.

Crystal structure of choline fenofibrate (Trilipix®), (C5H14NO) (C17H14ClO4)

2016 ◽  
Vol 31 (2) ◽  
pp. 142-148
Author(s):  
James A. Kaduk ◽  
Kai Zhong ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Strong Hydrogen Bond ◽  
Carboxylate Group ◽  
Powder Diffraction Data ◽  
Powder Diffraction File ◽  
X Ray

The crystal structure of choline fenofibrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Choline fenofibrate crystallizes in space group Pbca (#61) with a = 12.341 03(2), b = 28.568 70(6), c = 12.025 62(2) Å, V = 4239.84(1) Å3, and Z = 8. The hydroxyl group of the choline anion makes a strong hydrogen bond to the ionized carboxylate group of the fenofibrate anion. Together with C–H···O hydrogen bonds, these link the cations and anions into layers parallel to the ac-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

scholarly journals Crystal structures of two alanylpiperidine analogues

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Kalina Mambourg ◽  
Nikolay Tumanov ◽  
Gilles Henon ◽  
Steve Lanners ◽  
Javier Garcia-Ladona ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Risk Assessment ◽  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Strong Hydrogen Bond ◽  
Carboxylic Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Crystal Packings

The structure of ethyl 1-[N-(4-methylphenyl)-N-(methylsulfonyl)alanyl]piperidine-4-carboxylate, C19H28N2O5S, I, a compound of interest as activator of Ubiquitin C-terminal Hydrolase-L1 (UCH-L1), was determined by single-crystal X-ray diffraction (SCXRD) analysis. In order to find new activators, a derivative of compound I, namely, 1-[N-(4-methylphenyl)-N-(methylsulfonyl)alanyl]piperidine-4-carboxylic acid, C17H24N2O5S, II, was studied. The synthesis and crystal structure are also reported. Despite being analogues, different crystal packings are observed. Compound II bears a carboxylic group, which favors a strong hydrogen bond. A polymorph risk assessment was carried out to study interactions in compound II.

Diphenylboron complexes of the enol tautomers of arylpyruvic acids. Crystal and molecular structure of triethylammonium (2-nitrophenyl)pyruvato-diphenylboron(1-)

2000 ◽  
Vol 78 (5) ◽  
pp. 546-552 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jens O Pokriefke ◽  
Steven J Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Least Squares ◽  
Spectroscopic Data ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
X Ray

Synthesis has been carried out of 15 examples of anionic diphenylboron complexes of arylpyruvic acids, and the structures of the compounds have been determined from spectroscopic data and from X-ray analysis of one of the compounds. Crystals of5j are monoclinic, P21/n,a = 9.5566(10), b = 15.961(3), c = 16.6382(6) Å, beta = 99.3239(10)°, and Z = 4, at 180 K. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R(F2) = 0.056 for 6662 CCD data. 5j contains a triethylammonium cation and an anion containing a planar five-membered OBOCC ring, with cation and anion linked by an N-H···O hydrogen bond. Spectroscopic data and bond distances establish that the pyruvate ligand is the enol-tautomeric state.

The Molecular Structure and Hydrogen Bond Geometry in Liquid Formamide: Electron, Neutron, and X-Ray Diffraction Studies

1983 ◽  
Vol 38 (2) ◽  
pp. 231-236 ◽  
Author(s):  
E. Kálmán ◽  
I. Serke ◽  
G. Pálinkás ◽  
M. D. Zeidler ◽  
F. J. Wiesmann ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Electron Diffraction ◽  
Diffraction Data ◽  
Free Molecule ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Mean ◽  
Diffraction Patterns ◽  
Good Agreement

Abstract Electron, neutron and X-ray diffraction patterns of liquid formamide have been measured at a temperature of 25 °C. Analysis of the diffraction data yields the molecular structure and the average geometry of the hydrogen bond. The molecular parameters obtained from liquid diffraction experiments are in good agreement with those from gas electron diffraction for the free molecule. The mean O…N and O…H hydrogen bond distances are 2.9 Å and 1.9 Å, respectively. Four H-bonds per molecule are found on the average. The deviation of the H-bonds from the linearity is estimated.

Polysulfonylamine, CXLII [1]. Ein supramolekulares Monomer-Dimer-Paar: Starke und schwache Wasserstoffbrücken in den Kristallstrukturen von Pyridinium-dimesylamid und 4,4´-Bipyridindiium-bis(dimesylamid) / Polysulfonylamines, CXLII [1]. A Supramolecular Monomer-Dimer Pair: Strong and Weak Hydrogen Bonding in the Crystal Structures of Pyridinium Dimesylamide and 4,4´-Bipyridinediium Bis(dimesylamide)

2001 ◽  
Vol 56 (10) ◽  
pp. 1041-1051 ◽  
Author(s):  
Oliver Moers ◽  
Ilona Lange ◽  
Karna Wijaya ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Strong Hydrogen Bond ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Normalized Parameters ◽  
Hydrogen Bonding Networks

In order to study packing arrangements and hydrogen bonding networks, low-temperature X-ray structures were determined for pyH+(MeSO2)2N- (M, orthorhombic, space group P212121, Z′ = 1) and 4,4′-bipyH22+ ·(MeSO2)2N- (D, monoclinic, C2/c, Z′ = 0.5). The structures consist of ionic formula entities assembled by N+-H···N- hydrogen bonds; the dication in D displays crystallographic C2 symmetry and has its two pyridyl moieties twisted by 43.9°. According to the packing architectures, D represents a supramolecular dimer of the monomeric congener M. In particular, the (MeSO2)2N- ions of the M structure are associated via short C(sp3) - H···O contacts to form a diamondoid network, whereas in D a topologically congruent framework is constructed from weakly hydrogen-bonded [(MeSO2)N-]2 nodes. Hexagonal channels in the anion substructures each include two adjacent stacks of monomeric pyH+ or “dimeric” 4,4-bipyH22+ cations that are linked to the channel walls by the strong hydrogen bond(s) and a set of short Car-H···O contacts. All C - H···O taken into consideration have normalized parameters d(H···O) ≤ 270 pm and θ(C - H···O) ≥ 115°.

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