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

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.

2000 ◽  
Vol 55 (8) ◽  
pp. 677-684 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa Borowiak ◽  
Wiesław Z. Antkowiak

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.


1992 ◽  
Vol 45 (6) ◽  
pp. 969 ◽  
Author(s):  
KA Byriel ◽  
CHL Kennard ◽  
DE Lynch ◽  
G Smith ◽  
JG Thompson

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.


1998 ◽  
Vol 51 (2) ◽  
pp. 159 ◽  
Author(s):  
Graham Smith ◽  
Daniel E. Lynch ◽  
Raymond C. Bott

A number of molecular adducts of nitro-substituted aromatic acids with Lewis bases have been prepared and characterized by infrared spectroscopy and in three cases by X-ray diffraction methods. These three compounds are the adducts of: 3,5-dinitrobenzoic acid (dnba) with N-methylaniline (nma), [(dnba)-(nma)+] (1); (4-nitrophenyl)acetic acid (4-npa) with cyclohexane-1,4-diamine (dach), [(4-npa)22-(dach)2+] (4); 5-nitrosalicylic acid (5-nsa) with 2-imidazolidone (idaz), [(5-nsa)2(idaz)] (5). Other compounds are the adducts of 3,5-dinitrobenzoic acid with 2,6-dimethylpyridine (dmp), [(dnba)(dnba)-(dmp)+] (2), and with 1-methylpyrrole-2-carboxylic acid (cmp), [(dnba)-(cmp)+] (3). Compounds (1) and (3) have 1 : 1 stoichiometry, while (2), (4) and (5) are 2 : 1 adducts. Proton transfer occurs in most examples [complex (5) is the exception].


1994 ◽  
Vol 72 (7) ◽  
pp. 1621-1624 ◽  
Author(s):  
R.A. Bell ◽  
J.F. Britten ◽  
H.E. Howard-Lock ◽  
C.J.L. Lock ◽  
M. Schmidt

The reaction of D-penicillamine and benzaldehyde yielded 2-phenyl-5,5-dimethylthiazolidine-4-carboxylic acid. The structure was determined by single crystal X-ray diffraction. Crystals were monoclinic, P21, a = 9.785(2), b = 6.941(1), c = 10.399(2) Å, β = 114.06(3)°, Z = 2. Intensities were measured on a Rigaku AFC6R diffractometer with Cu Kα radiation and 1881 reflections were used to determine the structure. R = 0.076, wR = 0.048. The compound exists as an amino acid in the 2S,4S configuration. The conformation of the thiazolidine ring is determined by intermolecular hydrogen bonding. Bond lengths and angles are normal. 1H and 13C NMR spectra showed that epimerization takes place in d4-CH3OH solution, and the ratio of 2S,4S diastereomer to 2R,4S diastereomer at room temperature is 65:35.


Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.


2020 ◽  
Vol 7 (21) ◽  
pp. 4197-4221 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Jiří Sejkora

The structure, hydrogen bonding, X-ray diffraction pattern and mechanical properties of six important uranyl carbonate minerals, roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite, are determined using first principles methods.


2006 ◽  
Vol 62 (4) ◽  
pp. 606-611 ◽  
Author(s):  
Asiloé J. Mora ◽  
Michela Brunelli ◽  
Andrew N. Fitch ◽  
Jonathan Wright ◽  
Maria E. Báez ◽  
...  

The crystal structures of the four-membered heterocycles (S)-(−)-4-oxo-2-azetidinecarboxylic acid (I) and 3-azetidinecarboxylic acid (II) were solved by direct methods using powder synchrotron X-ray diffraction data. The asymmetry of the oxoazetidine and azetidine rings is discussed, along with the hydrogen bonding.


2000 ◽  
Vol 53 (12) ◽  
pp. 999 ◽  
Author(s):  
Graham Smith ◽  
Colin H. L. Kennard

The adduct hydrate of 1,1-diethylurea with pyrazine-2,3-dicarboxylic acid, [(C6H4N2O4)(C5H12N2O)].H2O has been prepared and characterized using low-temperature single-crystal X-ray diffraction methods. A primary asymmetric cyclic hydrogen-bonding interaction, similar to those found in other adducts of 1,1-diethylurea with the nitro-substituted aromatic acids, was found between the amide group of the substituted urea and one carboxylic acid group of the acid. Further peripheral hydrogen-bonding associations involving both the f irst and the second carboxylic acid groups, urea and the lattice water molecule result in a ribbon polymer structure.


2018 ◽  
Vol 73 (5) ◽  
pp. 281-288
Author(s):  
Qing Zhao ◽  
Ying-Qi Pan ◽  
Xiao-Yan Li ◽  
Han Zhang ◽  
Wen-Kui Dong

AbstractA discrete heterotrinuclear complex [{Ni2LDy(OAc)3(CH3OH)}2] · 2CH3OH · 3CH2Cl2, with a naphthalenediol-based acyclic bis(salamo) ligand H4L, has been synthesized and structurally characterized using elemental analyses, IR, UV/Vis and fluorescence spectra and single crystal X-ray diffraction. The crystal structure shows two crystallographically independent but chemically identical molecules (molecules I and II). All the Ni(II) atoms are hexa-coordinated with slightly distorted octahedral geometries. The central Dy atoms are nona-coordinated with slightly distorted tricapped trigonal prism geometries. An infinite 3D supramolecular structure is formed via intermolecular hydrogen bonding and C–H…π interactions.


2017 ◽  
Vol 73 (6) ◽  
pp. 481-485 ◽  
Author(s):  
Marimuthu Mohana ◽  
Packianathan Thomas Muthiah ◽  
Colin D. McMillen

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