Formation of isolated guest dimers vs. host-guest coordination. X-Ray crystal structures of four carboxylic acid inclusion compounds formed by roof-shaped and scissor-like host molecules

1990 ◽  
Vol 8 (3) ◽  
pp. 309-322 ◽  
Author(s):  
Ingeborg Cs�regh ◽  
M�ty�s Czugler ◽  
Edwin Weber ◽  
Jochen Ahrendt
Keyword(s):  
Carboxylic Acid ◽  
Crystal Structures ◽  
Inclusion Compounds ◽  
X Ray ◽  
Host Molecules

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.

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.

Solvent–guest control of two extremely similar tetrahydrofuran inclusion structures

2014 ◽  
Vol 70 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Jiabin Gao ◽  
Mohan M. Bhadbhade ◽  
Roger Bishop
Keyword(s):  
Crystal Structures ◽  
Inclusion Compounds ◽  
Crystal Form ◽  
Solvent Free ◽  
Guest Molecules ◽  
Crystal Forms ◽  
X Ray

Racemic 2,4,6,8-tetracarbomethoxybicyclo[3.3.0]octa-2,6-diene-3,7-diol, C16H18O10(1), was known previously to yield two solvent-free polymorphs and also a clathrate inclusion crystal form. Crystallization of (1) yields two inclusion compounds containing tetrahydrofuran (THF): (1)4·THF is obtained from a mixture of THF and methanol, whereas (1)2·THF is obtained from pure THF. The X-ray crystal structures reveal that the two compounds are extremely similar and that their host arrangements are essentially identical. They differ, however, in the proportion, orientation and host–guest interaction of the included THF molecules. The disordered guest molecules in (1)4·THF are oriented along the guest channel direction, whereas in (1)2·THF they lie across the channel. This unusual solvent–guest control of inclusion structures has implications relating to the formation of polymorphic structures and other competing crystal forms.

Inhibitors of the geotropic response in plants. The crystal structures of 2-[(Naphthalen-2-yl)carbamoyl]benzoic acid (β-Naptalam), 2-(Phenylcarbamoyl)-benzoic acid and 2-(5-Phenyl-1,3,4-oxadiazol-2-yl)benzoic acid

1983 ◽  
Vol 36 (12) ◽  
pp. 2455 ◽  
Author(s):  
G Smith ◽  
CHL Kennard ◽  
GF Katekar
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Benzoic Acid ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Acid Groups ◽  
Phthalamic Acid

The crystal structures of three geotropically active phthalamic acid derivatives have been determined by means of X-ray diffraction and the structural systematics for the series compared. The three acids are conformationally similar and, in contrast to the tendency among carboxylic acids to form hydrogen-bonded dimers, they exist as monomers with intermolecular hydrogen bonding between the carboxylic acid groups and the nitrogen or oxygen of the amide side chains.

Molecular Cocrystals of Carboxylic Acids. IX. Carboxylic Acid Interactions With Organic Heterocyclic Bases. The Crystal Structures of the Adducts of (2,4-Dichlorophenoxy)acetic Acid With 3-Hydroxypyridine, 2,4,6-Trinitrobenzoic Acid With 2-Aminopyrimidine, and 4-Nitrobenzoic Acid With 3-Amino-1,2,4-triazole

1992 ◽  
Vol 45 (6) ◽  
pp. 969 ◽  
Author(s):  
KA Byriel ◽  
CHL Kennard ◽  
DE Lynch ◽  
G Smith ◽  
JG Thompson
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrobenzoic Acid ◽  
Dichlorophenoxy Acetic Acid ◽  
Heterocyclic Bases

The cocrystal adducts of a number of carboxylic acids with organic heterocyclic bases have been prepared, and their structures and intermolecular interactions interpreted through X-ray diffraction and infrared spectroscopic techniques. The crystal structures of three of these compounds, the 1 : 1 adducts [{(2,4-dich1orophenoxy)acetic acid)(3-hydroxypyridine)] (1), [(2,4,6-trinitrobenzoie acid)(2-aminopyrimidine)] (2), and [(4-nitrobenzoic acid)(3-amino- 1,2,4-trimole)] (3), have been determined by single-crystal X-ray diffraction and refined to residuals R 0.026, 0.033 and 0.040 for 1814, 1531 and 727 observed reflections, respectively.

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