0000000000287381
AUTHOR
Liana Orola
Changes in freshwater sediment microbial populations during fermentation of crude glycerol
This work was supported by the Latvian Council of Science , project NN-CARMA, project No. lzp-2018/1-0194.
Bis(N,N′-diphenylbenzamidinium) fumarate
The crystal structure of the title compound, 2C(19)H(17)N(2) (+)·C(4)H(2)O(4) (2-), consists of centrosymmetric trimers built up of two crystallographically independent N,N'-diphenyl-benzamid-in-ium cations and one fumarate dianion, which is located on a centre of inversion. The components of the trimers are linked by N-H⋯O hydrogen bonding. In the cation, the outer rings make dihedral angles of 53.66 (5) and 78.38 (5)° with the central ring. The two outer rings make a dihdral angle of 81.49 (5)°.
Dipotassium 4,4′-(hexane-3,4-diyl)bis(benzenesulfonate) dihydrate
The anion of the title compound, also called sygethin dihydrate, 2K+·C18H20O6S22−·2H2O, has crystallographic inversion symmetry. The K+ cation is surrounded by eight O atoms in a distorted cubic coordination geometry, forming extended K—O—S networks. There are also O—H...O hydrogen bonds.
Mechanistic and kinetic insight into spontaneous cocrystallisation of isoniazid and benzoic acid
Solid-state cocrystallisation is of contemporary interest, because it offers an easy and efficient way to produce cocrystals, which are recognized as prospective pharmaceutical materials. Research explaining solid-state cocrystallisation mechanisms is important, but still too scarce to give a broad understanding of factors governing and limiting these reactions. Here we report an investigation of the mechanism and kinetics of isoniazid cocrystallisation with benzoic acid. This reaction is spontaneous; however its rate is greatly influenced by environmental conditions (humidity and temperature) and pre-treatment (milling) of the sample. The acceleration of cocrystallisation in the presence o…
Conformation of the umifenovir cation in the molecular and crystal structures of four carboxylic acid salts
The umifenovir salts of maleic, salicylic, glutaric, and gentisic acid as well as the chloroform solvate of the salicylate were prepared. Single crystals of the five compounds were obtained and their molecular and crystal structures determined by X-ray diffraction. In each structure the conformation of phenyl ring with respect to the indole group of the umifenovir moiety is different. The water solubility and melting points of the studied umifenovir salts have been determined.
Structure and Stability of Racemic and Enantiopure Pimobendan Monohydrates: On the Phenomenon of Unusually High Stability
Study of structures and physicochemical properties of racemic (rac-H) and enantiopure (enant-H) hydrates of the active pharmaceutical ingredient pimobendan revealed that both hydrates have highly similar crystal structures and exhibit unusually high stability. Both structures contain identical two-dimensional layers and very similar conformations. The most significant difference is the stacking of these layers. The high stability of both hydrates appeared as extremely low solubility over a wide temperature range as well as an exceptionally high dehydration temperature and melting point. Study of the dehydration process showed that both hydrates have different activation energies of dehydrat…
Single Enantiomer’s Urge to Crystallize in Centrosymmetric Space Groups: Solid Solutions of Phenylpiracetam
A detailed thermochemical and structural study of the phenylpiracetam enantiomer system was performed by characterizing the solid solutions, rationalizing the structural driving force for their formation, as well as identifying a common structural origin responsible for the formation of solid solutions of enantiomers. Enantiomerically pure phenylpiracetam forms two enantiotropically related polymorphs (enant–A and enant–B). The transition point (70(7) °C) was determined based on isobaric heat capacity measurements. Structural studies revealed that enant–A and enant–B crystallize in space groups P1 (Z′ = 4) and P212121 (Z′ = 2), respectively. However, pseudoinversion centers were present res…
Bis(N,N′-diphenylbenzamidinium) fumarate
The crystal structure of the title compound, 2C19H17N2+·C4H2O42−, consists of centrosymmetric trimers built up of two crystallographically independent N,N′-diphenylbenzamidinium cations and one fumarate dianion, which is located on a centre of inversion. The components of the trimers are linked by N—H...O hydrogen bonding. In the cation, the outer rings make dihedral angles of 53.66 (5) and 78.38 (5)° with the central ring. The two outer rings make a dihdral angle of 81.49 (5)°.
Isoniazid cocrystallisation with dicarboxylic acids: vapochemical, mechanochemical and thermal methods
Cocrystallisation with a series of related compounds allows for the exploration of trends and limitations set by structural differences between these compounds. In this work, we investigate how the length of a dicarboxylic acid influences the outcome of cocrystallisation with isoniazid. We have performed a systematic study on the mechanochemical, thermal and solvent vapour-assisted cocrystallisation of aliphatic dicarboxylic acids (C3–C10) with isoniazid. Our results demonstrate that the rate of mechanochemical and vapour-assisted cocrystallisation depends on the acid chain length and shows alternation between odd- and even-chain acids. The results of thermal cocrystallisation showed that t…
Crystal and Molecular Structure and Stability of Isoniazid Cocrystals with Selected Carboxylic Acids
Reaction of isoniazid with benzoic acid, sebacic acid, suberic acid, and cinnamic acid results in formation of cocrystals. Two polymorphs of isoniazid–suberic acid and two polymorphs of isoniazid–cinnamic acid cocrystals were isolated. Crystal structure analysis shows the presence of a pyridine–carboxylic acid synthon in the studied cocrystals. The hydrazide group of isoniazid participates in N–H···O and N–H···N hydrogen bond formation, producing different supramolecular synthons. The stability study of isoniazid cocrystals has been performed over a 22 week period. A comparison of melting points of isoniazid–dicarboxylic acid 2:1 cocrystals shows the decrease of melting point with an increa…
The effect of pH on polymorph formation of the pharmaceutically active compound tianeptine.
The anti-depressant pharmaceutical tianeptine has been investigated to determine the dynamics of polymorph formation under various pH conditions. By varying the pH two crystalline polymorphs were isolated. The molecular and crystal structures have been determined to identify the two polymorphs. One polymorph is an amino carboxylic acid and the other polymorph is a zwitterion. In the solid state the tianeptine moieties are bonded through hydrogen bonds. The zwitterion was found to be less stable and transformed to the acid form. During this investigation an amorphous form was identified.
Dipotassium 4,4'-(hexane-3,4-di-yl)bis-(benzene-sulfonate) dihydrate.
The anion of the title compound, also called sygethin dihydrate, 2K(+)·C(18)H(20)O(6)S(2) (2-)·2H(2)O, has crystallographic inversion symmetry. The K(+) cation is surrounded by eight O atoms in a distorted cubic coordination geometry, forming extended K-O-S networks. There are also O-H⋯O hydrogen bonds.
Spontaneous cocrystal hydrate formation in the solid state: crystal structure aspects and kinetics
Kinetics of anhydrous cocrystal hydration and that of cocrystal monohydrate formation from starting compounds in the solid state are studied as a function of RH and time. The propensity of the anhydrate to hydration is related to the crystal structures of anhydrous and hydrated forms.
Protonation effects on the UV/Vis absorption spectra of imatinib: A theoretical and experimental study
An experimental and theoretical investigation of protonation effects on the UV/Vis absorption spectra of imatinib showed systematic changes of absorption depending on the pH, and a new absorption band appeared below pH 2. These changes in the UV/Vis absorption spectra were interpreted using quantum chemical calculations. The geometry of various imatinib cations in the gas phase and in ethanol solution was optimized with the DFT/B3LYP method. The resultant geometries were compared to the experimentally determined crystal structures of imatinib salts. The semi-empirical ZINDO-CI method was employed to calculate the absorption lines and electronic transitions. Our study suggests that the forma…
Nicotinamide fumaric acid supramolecular cocrystals: diversity of stoichiometry
Synthesis of nicotinamide and fumaric acid supramolecular cocrystals with 1 : 1 and 2 : 1 amide to acid stoichiometries results in the formation of an amide–acid heterosynthon (1 : 1 stoichiometry) and an amide–amide homosynthon (2 : 1 stoichiometry) and different conformations of the fumaric acid moieties.
The conformation of pyrogallol as a result of cocrystallization with N-heterocyclic bases
Structural analysis of the supramolecular cocrystals formed by pyrogallol with acridine, 4,4′-bipyridine, and 1,10-phenanthroline shows that the studied cocrystals are assembled via the hydroxyl–pyridine heterosynthon. In the crystal and molecular structures of these cocrystals in order to form the maximum number of hydrogen bonds, taking into consideration steric effects, the pyrogallol moiety in the supramolecular arrangement has the following conformations: with acridine - syn1, 4,4′-bipyridine - anti, and 1,10-phenanthroline - syn2. Discrete supramolecular complexes are formed by acridine–pyrogallol and the 1,10-phenanthroline–pyrogallol polymorph I. The 1,10-phenanthroline–pyrogallol p…
A Maze of Solid Solutions of Pimobendan Enantiomers: An Extraordinary Case of Polymorph and Solvate Diversity
Over 10 polymorphs and solvatomorphs of the chiral pharmaceutically active ingredient pimobendan were found to lack enantioselectivity in the solid state, accordingly, forming solid solutions of enantiomers, which is reported to be a rare phenomenon. Solid form screening was performed on different enantiomeric composition samples to analyze obtained phases with powder X-ray diffraction and thermogravimetric differential scanning calorimetry. For nonsolvated forms, a melt phase diagram has been constructed convincingly showing the existence of stable and metastable solid solutions near the pure enantiomer and around the racemic composition regions. A crystal structure study combined with sol…
N-(2,6-Dimethylanilino)-5,6-dihydro-4H-1,3-thiazin-3-ium chloride monohydrate
In the title compound, alternatively called xylazine hydro-chloride monohydrate, C(12)H(17)N(2)S(+)·Cl(-)·H(2)O, the six-membered thia-zine ring is in a half-chair conformation. In the crystal structure, six component centrosymmetric clusters are formed via inter-molecular O-H⋯Cl, N-H⋯O and N-H⋯Cl hydrogen bonds involving xylazine cations, chloride anions and water mol-ecules.
CCDC 931509: Experimental Crystal Structure Determination
Related Article: Liana Orola, Inese Sarcevica, Artis Kons, Andris Actins, Mikelis V. Veidis|2014|J.Mol.Struct.|1056|63|doi:10.1016/j.molstruc.2013.10.010
CCDC 931507: Experimental Crystal Structure Determination
Related Article: Liana Orola, Inese Sarcevica, Artis Kons, Andris Actins, Mikelis V. Veidis|2014|J.Mol.Struct.|1056|63|doi:10.1016/j.molstruc.2013.10.010
CCDC 931511: Experimental Crystal Structure Determination
Related Article: Liana Orola, Inese Sarcevica, Artis Kons, Andris Actins, Mikelis V. Veidis|2014|J.Mol.Struct.|1056|63|doi:10.1016/j.molstruc.2013.10.010
CCDC 890182: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Mikelis V.Veidis, Anton Podjava, and Sergey Belyakov|2013|Cryst.Growth Des.|13|1082|doi:10.1021/cg301356h
CCDC 931510: Experimental Crystal Structure Determination
Related Article: Liana Orola, Inese Sarcevica, Artis Kons, Andris Actins, Mikelis V. Veidis|2014|J.Mol.Struct.|1056|63|doi:10.1016/j.molstruc.2013.10.010
CCDC 890184: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Mikelis V.Veidis, Anton Podjava, and Sergey Belyakov|2013|Cryst.Growth Des.|13|1082|doi:10.1021/cg301356h
CCDC 890181: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Mikelis V.Veidis, Anton Podjava, and Sergey Belyakov|2013|Cryst.Growth Des.|13|1082|doi:10.1021/cg301356h
CCDC 890180: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Mikelis V.Veidis, Anton Podjava, and Sergey Belyakov|2013|Cryst.Growth Des.|13|1082|doi:10.1021/cg301356h
CCDC 890183: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Mikelis V.Veidis, Anton Podjava, and Sergey Belyakov|2013|Cryst.Growth Des.|13|1082|doi:10.1021/cg301356h
CCDC 933429: Experimental Crystal Structure Determination
Related Article: Inese Sarcevica, Liana Orola, Sergey Belyakov, Mikelis V. Veidis|2013|New J.Chem.|37|2978|doi:10.1039/C3NJ00489A
CCDC 931508: Experimental Crystal Structure Determination
Related Article: Liana Orola, Inese Sarcevica, Artis Kons, Andris Actins, Mikelis V. Veidis|2014|J.Mol.Struct.|1056|63|doi:10.1016/j.molstruc.2013.10.010