X-ray evidence of temperature-dependent conformational disorder of hydrogen-bonded carboxylic acid molecules in crystal structures

Nature ◽  
1975 ◽  
Vol 257 (5527) ◽  
pp. 625-626 ◽  
Author(s):  
J. A. KANTERS ◽  
G. ROELOFSEN ◽  
J. KROON
Keyword(s):  
Carboxylic Acid ◽  
Crystal Structures ◽  
Temperature Dependent ◽  
Conformational Disorder ◽  
X Ray ◽  
Hydrogen Bonded

Synthesis and X-ray crystal structures of dinuclear hydrogen-bonded cadmium and lead 2-aminoethanethiolates

Polyhedron ◽  
2005 ◽  
Vol 24 (8) ◽  
pp. 865-871 ◽  
Author(s):  
Mohan S. Bharara ◽  
Chong H. Kim ◽  
Sean Parkin ◽  
David A. Atwood
Keyword(s):  
Crystal Structures ◽  
X Ray ◽  
Cadmium And Lead ◽  
Hydrogen Bonded

Metal Phenoxyalkanoic Acid Interactions. XXV. The Crystal Structures of (2-Formyl-6-Methoxyphenoxy)Acetic Acid and Its Zinc(II) Complex and the Lithium, Zinc(II) and Cadmium(II) Complexes of (2-Chlorophenoxy)Acetic Acid

1987 ◽  
Vol 40 (7) ◽  
pp. 1147 ◽  
Author(s):  
EJ Oreilly ◽  
G Smith ◽  
CHL Kennard ◽  
TCW Mak
Keyword(s):  
Acetic Acid ◽  
Crystal Structures ◽  
Free Acid ◽  
Rotational Symmetry ◽  
Carboxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Planar Complex ◽  
Hydrogen Bonded

The crystal structures of (2-formyl-6-methoxyphenoxy)acetic acid (1), diaquabis [(2-formyl-6-methoxyphenoxy) acetato ]zinc(11) (2), tetraaquabis [(2-chlorophenoxy) acetato ]zinc(11) (3), triaquabis [(2-chlorophenoxy) acetato ]cadmium(11) dihydrate (4) and lithium (2-chloro- phenoxy )acetate 1.5 hydrate (5) have been determined by X-ray diffraction. The acid (1) forms centrosymmetric hydrogen-bonded cyclic dimers [O…0, 2.677(6) �] which are non-planar. Complex (2) is six-coordinate with two waters [Zn- Ow , 1.997(2) �] and four oxygens from two asymmetric bidentate carboxyl groups [Zn-O, 2.073, 2.381(2) �] completing a skew trapezoidal bipyramidal stereochemistry. Complex (5) is also six-coordinate but is octahedral, with two trans-related unidentate carboxyl oxygens [mean Zn-O, 2.134(9) �] and four waters [mean Zn-O, 2.081(9) �]. The seven-coordinate complex (4) has crystallographic twofold rotational symmetry relating two :symmetric bidentate acid ligands [ Cd -O, 2.26, 2 48(:) �] and two waters [ Cd -O, 2.34(2) �] while the third water lies on this axis [ Cd -O, 2.27(2) �]. In contrast to the monomers (2)-(4), complex (5) is polymeric with tetrahedral lithium coordinated to one water and three carboxylate oxygens [mean Li-0, 1.95(1) �]. The essential conformation of the free acid is retained in complexes (2), (3) and (4) but in (5), it is considerably changed.

Hydrogen Bonds in "Carboxyoximes": the Case of Bomane Derivatives

2000 ◽  
Vol 55 (8) ◽  
pp. 677-684 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa Borowiak ◽  
Wiesław Z. Antkowiak
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Supramolecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Groups ◽  
Acid Function

Abstract The tendency of forming mixed carboxyl-to-oxime hydrogen bonds was tested on the series of bornane derivatives: one with the acid function only (bornane-2-endo-carboxylic acid), one with the oxime function (2,2′-diethylthiobomane-3-oxime), and one with both oxime and carboxylic functions (bornane-2-oxime-3-endo-carboxylic acid). The crystal structures of these compounds were determined by means of X-ray diffraction. In bornane-2-endo-carboxylic acid and 2,2′-diethylthiobornane-3-oxime 'homogenic' hydrogen bonds were found, and these hydrogen bonds close eight-and six-membered rings, respectively. By contrast, in bornane-2-oxime-3-endo-carboxylic acid 'heterogenic' hydrogen bonds between carboxylic and oxime bonds were found. This carboxylic-oxime, or 'carboxyoxime' system is almost always present in compounds which have both oxime and carboxylic groups; therefore it can be regarded as an element of supramolecular structures (synthon). The presence of such synthons can break the tendency of carboxylic acids and oximes towards crystallizing in centrosymmetric structures.

scholarly journals Neutron and high-pressure X-ray diffraction study of hydrogen-bonded ferroelectric rubidium hydrogen sulfate

2016 ◽  
Vol 72 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Jack Binns ◽  
Garry J McIntyre ◽  
Simon Parsons
Keyword(s):  
High Pressure ◽  
Applied Pressure ◽  
Ferroelectric Material ◽  
Ferroelectric Materials ◽  
Hydrogen Sulfate ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Pressure Phase ◽  
Hydrogen Bonded

The pressure- and temperature-dependent phase transitions in the ferroelectric material rubidium hydrogen sulfate (RbHSO4) are investigated by a combination of neutron Laue diffraction and high-pressure X-ray diffraction. The observation of disordered O-atom positions in the hydrogen sulfate anions is in agreement with previous spectroscopic measurements in the literature. Contrary to the mechanism observed in other hydrogen-bonded ferroelectric materials, H-atom positions are well defined and ordered in the paraelectric phase. Under applied pressure RbHSO4undergoes a ferroelectric transition before transforming to a third, high-pressure phase. The symmetry of this phase is revised to the centrosymmetric space groupP21/c, resulting in the suppression of ferroelectricity at high pressure.

scholarly journals Engineering short, strong hydrogen bonds in urea di-carboxylic acid complexes

CrystEngComm ◽  
2014 ◽  
Vol 16 (35) ◽  
pp. 8177-8184 ◽  
Author(s):  
Andrew O. F. Jones ◽  
Charlotte K. Leech ◽  
Garry J. McIntyre ◽  
Chick C. Wilson ◽  
Lynne H. Thomas
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Neutron Diffraction ◽  
Structural Changes ◽  
Acid Amide ◽  
Molecular Complexes ◽  
Temperature Dependent ◽  
X Ray ◽  
Methyl Substitution

The persistence of the acid⋯amide heterodimer and the effect of methyl substitution on the short strong O–H⋯O hydrogen bond is investigated in urea and methylurea di-carboxylic acid molecular complexes. Temperature dependent structural changes are also reported utilising X-ray and neutron diffraction in tandem.

Thermal expansion of β-succinic acid and α-adipic acid in relation to their crystal structures

1965 ◽  
Vol 285 (1402) ◽  
pp. 370-381 ◽  
Keyword(s):  
Thermal Expansion ◽  
Succinic Acid ◽  
Crystal Structures ◽  
Adipic Acid ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Molecular Packing ◽  
X Ray ◽  
Angular Vibration ◽  
Hydrogen Bonded

The thermal expansion quadrics of β -succinic acid and α -adipic acid have been determined by X-ray Weissenberg method. In adipic acid, X-ray measurements have been made between —100 and +100°C and in succinic acid between —150 and +130°C. In these monoclinic crystals, the minimum expansion corresponds to the c axis, which coincides with the direction of the hydrogen-bonded molecular columns. In other directions along which van der Waals forces prevail, thermal expansion is greater, being maximum perpendicular to the (100) planes, the direction of the obtuse bisectrix of the molecular packing angle. The thermal expansion is quantitatively explained by assuming an increase in the angular vibration of the molecules.

Supramolecular architectures in two 1:1 cocrystals of 5-fluorouracil with 5-bromothiophene-2-carboxylic acid and thiophene-2-carboxylic acid

2017 ◽  
Vol 73 (6) ◽  
pp. 481-485 ◽  
Author(s):  
Marimuthu Mohana ◽  
Packianathan Thomas Muthiah ◽  
Colin D. McMillen
Keyword(s):  
Solid State ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Base Pairs ◽  
X Ray ◽  
Supramolecular Architectures ◽  
Acid Acid ◽  
Carboxylic Acid Dimer

In solid-state engineering, cocrystallization is a strategy actively pursued for pharmaceuticals. Two 1:1 cocrystals of 5-fluorouracil (5FU; systematic name: 5-fluoro-1,3-dihydropyrimidine-2,4-dione), namely 5-fluorouracil–5-bromothiophene-2-carboxylic acid (1/1), C5H3BrO2S·C4H3FN2O2, (I), and 5-fluorouracil–thiophene-2-carboxylic acid (1/1), C4H3FN2O2·C5H4O2S, (II), have been synthesized and characterized by single-crystal X-ray diffraction studies. In both cocrystals, carboxylic acid molecules are linked through an acid–acid R 2 2(8) homosynthon (O—H...O) to form a carboxylic acid dimer and 5FU molecules are connected through two types of base pairs [homosynthon, R 2 2(8) motif] via a pair of N—H...O hydrogen bonds. The crystal structures are further stabilized by C—H...O interactions in (II) and C—Br...O interactions in (I). In both crystal structures, π–π stacking and C—F...π interactions are also observed.

Sign in / Sign up

Export Citation Format

Share Document