Structures of three salts of phthalic acid; variation in crystal packing and geometry of the hydrogen phthalate ion

2004 ◽  
Vol 60 (5) ◽  
pp. 502-511 ◽  
Author(s):  
Annette Langkilde ◽  
Dennis Madsen ◽  
Sine Larsen
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Phthalic Acid ◽  
Crystal Packing ◽  
Molecular Geometry ◽  
Hydrogen Phthalate ◽  
Acid Base ◽  
Hydrogen Bond Pattern ◽  
Structural Database

The hydrogen-bond patterns in hydrogen phthalates (HP) have been elucidated by the determination of the crystal structures of hydrogen phthalate salts of [Mg(H2O)4-(CH3OH)2]2+, 2-(2′-pyridylamine)pyridinium and diethylammonium. The stoichiometry of the latter salt corresponds to a hydrogen phthalate salt; however, it contains the phthalic acid in its three possible acid–base forms. The hydrogen phthalate ions in the three salts display the two common hydrogen-bonding motifs. One has a very short intramolecular O—H—O hydrogen bond (Intra-H), as seen in the magnesium salt [O...O 2.397 (2) Å]. In the other two salts the hydrogen phthalate ions are connected by hydrogen bonds into infinite chains (Chain-H) with O...O distances of 2.460 (1) Å in the diethylamine salt and 2.610 (1) Å in the 2,2′-dipyridylamine salt. This difference in hydrogen-bond pattern was further elucidated by a search in the Cambridge Structural Database for other hydrogen phthalate salts. Intra-H possesses the shortest O...O distances and an almost planar hydrogen phthalate ion, whereas the hydrogen phthalate ions show significantly more variation in the Chain-H salts. The two hydrogen-bonding motifs are reflected in the molecular geometry of the hydrogen phthalate ion.

N-tert-Butyl-N′-[5-cyano-2-(4-methylphenoxy)phenylsulfonyl]urea, a new TXA2receptor antagonist

2013 ◽  
Vol 69 (8) ◽  
pp. 901-903
Author(s):  
Sylvie-Mireille Bambi-Nyanguile ◽  
Peter Mangwala Kimpende ◽  
Bernard Pirotte ◽  
Luc Van Meervelt
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Theoretical Calculations ◽  
Intramolecular Hydrogen Bonding ◽  
Asymmetric Unit ◽  
Dimer Formation ◽  
Compound C ◽  
Structural Database ◽  
Intramolecular Hydrogen

The title compound, C19H21N3O4S, crystallizes in the space groupP2/cwith two molecules in the asymmetric unit. The conformation of both molecules is very similar and is mainly determined by an intramolecular N—H...O hydrogen bond between a urea N atom and a sulfonyl O atom. The O and second N atom of the urea groups are involved in dimer formationviaN—H...O hydrogen bonds. The intramolecular hydrogen-bonding motif and conformation of the C—SO2—NH(C=O)—NH—C fragment are explored and compared using the Cambridge Structural Database and theoretical calculations. The crystal packing is characterized by π–π stacking between the 5-cyanobenzene rings.

scholarly journals X-RAY DETERMINATION OF THE STRUCTURE OF ANHYDROUS DIPHENYLCYCLOPROPENONE. VARIATIONS OF THE MOLECULAR GEOMETRY DUE TO HYDROGEN BONDING

1974 ◽  
Vol 3 (6) ◽  
pp. 639-642 ◽  
Author(s):  
Harumichi Tsukada ◽  
Hirotaka Shimanouchi ◽  
Yoshio Sasada
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Geometry ◽  
X Ray

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

Hydrogen-Bonding Schemes of Galactonic Acid Hydrazide and its Hemihydrate

1997 ◽  
Vol 53 (3) ◽  
pp. 490-497 ◽  
Author(s):  
C. André ◽  
P. Luger ◽  
J.-H. Fuhrhop ◽  
F. Hahn
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Scintillation Counter ◽  
Acid Hydrazide ◽  
Coordination Shell ◽  
Hydroxyl Group ◽  
Free Sugar ◽  
Imaging Plate

The crystal structure of L-galactonic acid hemihydrate was determined using data obtained from an imaging plate detector (Stoe IPDS), whereas a conventional scintillation counter was used for the elucidation of the crystal structure of anhydrous D-galactonic acid. The H atom of the terminal hydroxyl group of the water-free sugar participates only in an intramolecular hydrogen bond with the preterminal O atom. This hydrogen bond is part of an antidromic hydrogen-bonding cycle. The hydrogen-bonding scheme of the hemihydrate is very intricate due to the occurrence of two independent molecules and the incorporated water, whose coordination shell can be described by a distorted tetrahedron. One of the hydrogen-bond chains observed in the structure of the hemihydrate is infinite, forming a spiral running in the a direction. The crystal packing of both compounds displays a herringbone arrangement. However, the tilt angle between molecules in different herringbone halves is by far smaller in the structure of the hydrated sugar than in the water-free compound (~ 60 versus 96°).

Hydrogen bonding in enantiomeric versus racemic mono-carboxylic acids; a case study of 2-phenoxypropionic acid

2003 ◽  
Vol 59 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Henning Osholm Sørensen ◽  
Sine Larsen
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Crystal Packing ◽  
Cyclic Dimer ◽  
Optically Pure ◽  
Pure Enantiomer ◽  
Hydrogen Bonded

The structural and thermodynamic backgrounds for the crystallization behaviour of racemates have been investigated using 2-phenoxypropionic acid (PPA) as an example. The racemate of PPA behaves normally and forms a racemic compound that has a higher melting point and is denser than the enantiomer. Low-temperature crystal structures of the pure enantiomer, the enantiomer cocrystallized with n-alkanes and the racemic acid showed that hydrogen-bonded dimers that form over crystallographic symmetry elements exist in all but the structure of the pure enantiomer. A database search for optically pure chiral mono-carboxylic acids revealed that the hydrogen-bonded cyclic dimer is the most prevalent hydrogen-bond motif in chiral mono-carboxylic acids. The conformation of PPA depends on the hydrogen-bond motif; the antiplanar conformation relative to the ether group is associated with a catemer hydrogen-bonding motif, whereas the more abundant synplanar conformation is found in crystals that contain cyclic dimers. Other intermolecular interactions that involve the substituent of the carboxylic group were identified in the crystals that contain the cyclic dimer. This result shows how important the nature of the substituent is for the crystal packing. The differences in crystal packing have been related to differences in melting enthalpy and entropy between the racemic and enantiomeric acids. In a comparison with the equivalent 2-(4-chlorophenoxy)-propionic acids, the differences between the crystal structures of the chloro and the unsubstituted acid have been identified and related to thermodynamic data.

An Effective Acid–Base-Induced Liquid–Liquid Microextraction Based on Deep Eutectic Solvents for Determination of Testosterone and Methyltestosterone in Milk

2020 ◽  
Vol 58 (9) ◽  
pp. 880-886
Author(s):  
Xiao Li ◽  
Tao Yuan ◽  
Ting Zhao ◽  
Xiaomei Wu ◽  
Yaling Yang
Keyword(s):  
Hydrogen Bond ◽  
Hydrochloric Acid ◽  
High Performance ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Hydrogen Bond Donor ◽  
Acid Base ◽  
Hydrogen Bond Acceptor ◽  
Liquid Microextraction

Abstract An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.

A Comparison of the Enamino Carbonyl Conjugation Efficiency for Hydrogen Bonding Formation in Pyridone and Dihydropyridone Systems

2000 ◽  
Vol 55 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Teresa Borowiak ◽  
Irena Wolska ◽  
Artur Korzański ◽  
Wolfgang Milius ◽  
Wolfgang Schnick ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Steric Hindrance ◽  
Crystal Packing ◽  
Intermolecular Hydrogen Bond ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds

The crystal structures of two compounds containing enaminone heterodiene systems and forming intermolecular hydrogen bonds N-H·O are reported: 1) 3-ethoxycarbonyl-2-methyl-4-pyridone (hereafter ETPY) and 2) 3-ethoxycarbonyl-2-phenyl-6-methoxycarbonyl-5,6-di-hydro-4-pyridone (hereafter EPPY). The crystal packing is controlled by intermolecular hydro­ gen bonds N-H·O = C connecting the heteroconjugated enaminone groups in infinite chains. In ETPY crystals the intermolecular hydrogen bond involves the heterodienic pathway with the highest π-delocalization that is effective for a very short N·O distance of 2.701(9) Å (average from two molecules in the asymmetric unit). Probably due to the steric hindrance, the hydrogen bond in EPPY is formed following the heterodienic pathway that involves the ester C = O group, although π-delocalization along this pathway is less than that along the pyridone-part pathway resulting in a longer N·O distance of 2.886(3) Å

Insights into the C–H⋯F–C hydrogen bond by Cambridge Structural Database analyses and computational studies

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26932-26940 ◽  
Author(s):  
Sagarika Dev ◽  
Sudeep Maheshwari ◽  
Angshuman Roy Choudhury
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Ab Initio ◽  
Gas Phase ◽  
Cambridge Structural Database ◽  
Computational Studies ◽  
Structural Database

C–H⋯F–C hydrogen bonding is analysed among fluorinated ethenes using ab initio calculations in the gas phase to understand the nature, strength and directionality of these interactions.

scholarly journals Towards an understanding of the propensity for crystalline hydrate formation by molecular compounds

IUCrJ ◽  
2016 ◽  
Vol 3 (6) ◽  
pp. 430-439 ◽  
Author(s):  
Alankriti Bajpai ◽  
Hayley S. Scott ◽  
Tony Pham ◽  
Kai-Jie Chen ◽  
Brian Space ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Crystal Packing ◽  
Hydrate Formation ◽  
Crystalline Hydrate ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Screening Experiments ◽  
Group Form ◽  
Structural Database ◽  
Molecular Compounds

Hydrates are technologically important and ubiquitous yet they remain a poorly understood and understudied class of molecular crystals. In this work, we attempt to rationalize propensity towards hydrate formation through crystallization studies of molecules that lack strong hydrogen-bond donor groups. A Cambridge Structural Database (CSD) survey indicates that the statistical occurrence of hydrates in 124 molecules that contain five- and six-memberedN-heterocyclic aromatic moieties is 18.5%. However, hydrate screening experiments on a library of 11N-heterocyclic aromatic compounds with at least two acceptor moieties and no competing hydrogen-bond donors or acceptors reveals that over 70% of this group form hydrates, suggesting that extrapolation from CSD statistics might, at least in some cases, be deceiving. Slurrying in water and exposure to humidity were found to be the most effective discovery methods. Electrostatic potential maps and/or analysis of the crystal packing in anhydrate structures was used to rationalize why certain molecules did not readily form hydrates.

Sign in / Sign up

Export Citation Format

Share Document