Crystal structures, thermal stabilities, and dissolution behaviours of tinidazole and the tinidazole–vanillic acid cocrystal: insights from energy frameworks

2020 ◽  
Vol 76 (5) ◽  
pp. 389-397
Author(s):  
Kang Zheng ◽  
Changjian Xie ◽  
Xiaowei Li ◽  
Weiwei Wu ◽  
Ao Li ◽  
...  

The crystal structures of the antimicrobial drug tinidazole [TNZ; systematic name: 1-(2-ethylsulfonylethyl)-2-methyl-5-nitroimidazole, C8H13N3O4S] and the 1:1 cocrystal of TNZ with the naturally occurring compound vanillic acid (VA; systematic name: 4-hydroxy-3-methoxybenzoic acid, C8H8O4), namely, the TNZ–VA cocrystal, were determined by single-crystal X-ray analysis at 100 K. The supramolecular structure of the TNZ–VA cocrystal is composed of a carboxylic acid dimer and an O—H...N(heterocycle) synthon in the form of layers made up of O—H...N and O—H...O hydrogen bonds. The layers are joined via C—H...O hydrogen bonds, π–π stacking and C—H...π interactions. The energy framework analysis, together with interaction energy calculations using the DLPNO-CCSD(T) method, indicates that the TNZ–VA cocrystal inherits strong interactions from the TNZ and VA crystals, which accounts for the enhanced thermal stability and reduced dissolution rate. To the best of our knowledge, this is the first example of a cocrystal containing TNZ.

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.


1982 ◽  
Vol 37 (11) ◽  
pp. 1393-1401 ◽  
Author(s):  
Beatrix Milewski-Mahrla ◽  
Hubert Schmidbaur

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter­actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.


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.


2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.


1985 ◽  
Vol 38 (3) ◽  
pp. 401 ◽  
Author(s):  
MJ O'Connell ◽  
CG Ramsay ◽  
PJ Steel

The colourless crystalline form of the benzoylpyrazolone (2) has molecules with the NH structure (2c) stabilized by intermolecular hydrogen bonds. At room temperature crystals are monoclinic: P21/c, a 13.508(5), b 9.124(4), c 11.451(3)Ǻ, β 90.80(3)°, Z4; the structure was refined to R 0.059, Rw 0.048. The acetoacetylpyrazolone (3) has the OH structure (3c) with two intramolecular hydrogen bonds. At 193 K crystals are triclinic: Pī , a 7.142(2), b 13.704(8), c 14.699(7)Ǻ, α 117.36(3), β 96.87(3), γ 93.73(3)°, Z 4; the structure was refined to R 0.049, Rw 0.054.


1977 ◽  
Vol 32 (11) ◽  
pp. 1230-1238 ◽  
Author(s):  
Heinz Dieter Lutz ◽  
Saleh M. El-Suradi ◽  
Bernward Engelen

IR, Raman, and X-ray data of ZnSO3 · 2½ H2O, ZnSO3 · 2 H2O, ZnSO3 ·½ H2O, ZnSO3, MnSO3 · 3 H2O, MnSO3 · H2O, MnSO3, MgSO3 · 6 H2O, MgSO3 · 3 H2O, CoSO3 · 3 H2O, CoSO3 · 2½ H2O, and CoSO3·2 H2O are presented. Except of MgSO3·6 H2O and ZnSO3 · 2½ H2O the crystal structures of these compounds are yet unknown. The following crystal data could be determined by single crystal measurements: ZnSO3 · 2 H2O (monoclinic, P21/n) : a = 642.1, b = 852.4, c = 757.4 pm, β = 98.93°, Z = 4, MnSO3 · 3 Η2Ο (monoclinic, Ρ21/n) : a = 665.0, b = 890.6, c = 879.3 pm, ß = 96.11°, Z = 4, MnSO3 · Η2Ο (orthorhombic) : a = 2565.1, b = 483.9, c = 576.0 pm, Z = 8, CoSO3 · 3 Η2Ο (orthorhombic, Pna21, isotype with MgSO3 · 3 H2O): a = 952.7, b = 942.0, c = 552.1 pm, Z = 4, CoSO3• 2½ H2O (tetragonal) : a = b = 946.4, c = 1021.1 pm, Z = 8, CoSO3 · 2 H2O (isotype with ZnSO3 · 2 H2O) : a = 639.7, b = 855.3, c = 753.7 pm, β = 98.85°, Z = 4. The IR spectra show that with exception of MnSO3· H2O strong hydrogen bonds are present in the sulfite hydrates. The decomposition of the sulfites has been examined by thermal analysis. Dehydration of the sulfite hydrates starts at 90 (ZnSO3 · 2½ H2O), 120 (ZnSO3 · 2 H2O), 175 (ZnSO3 · 1/2 H2O), 85 (MnSO3 · 3 H2O), 205 (MnSO3 · H2O), 70 (MgSO3 · 6 H2O), 130 (MgSO3 · 3 H2O), 120 (CoSO3 · 3 H2O), 140 (CoSO3 · 2½ H2O), and 150 °C (CoSO3 · 2 H2O). Decomposition of the anhydrous sulfites occurs at 300-350 (ZnSO3), 390-460 (MnSO3), and 400-530 °C (MgSO3).


2007 ◽  
Vol 63 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Andrew Parkin ◽  
Martin Adam ◽  
Richard I. Cooper ◽  
Derek S. Middlemiss ◽  
Chick C. Wilson

A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol−1), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.


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