Strategic synthon approach in obtaining cocrystals and cocrystal polymorphs of a high-Z′ system deferiprone – an anti-thalassemia drug

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Satyasree Rajendrakumar ◽  
Anuja Surampudi Venkata Sai Durga ◽  
Sridhar Balasubramanian
Keyword(s):  
Phase Transformation ◽  
Hydrogen Bonding ◽  
Thermal Behaviour ◽  
Crystal Packing ◽  
Rietveld Analysis ◽  
Hydroxyl Group ◽  
Asymmetric Unit ◽  
Melting Points

Compounds with more than one molecule in the crystallographic asymmetric unit (Z′ > 1) display a noticeably stronger propensity to form cocrystals. Deferiprone is an anti-thalassemia drug known to exhibit polymorphic behaviour. Previously, three polymorphs were reported out of which one of them exhibited Z′ > 1. In the present manuscript, a fourth polymorph of deferiprone was identified and it also possessed Z′ > 1. All the four polymorphs showed similar hydrogen bonding features and differed in crystal packing. The ability of deferiprone to crystallize as Z′ > 1 prompted us to investigate the hydrogen bonding and synthon variation upon cocrystallization of deferiprone with hydroxyl-group-containing coformers such as catechol, hydroquinone, phloroglucinol, resorcinol and pyrogallol. Crystallization attempts along with PXRD analysis aided in obtaining 11 new cocrystal structures which involve different stoichiometric cocrystals and some polymorphs. Synthon analysis, crystal packing as well as thermal behaviour were assessed and compared. The presence of multiple phases in each cocrystal system in its respective bulk powders was identified and quantified using PXRD and Rietveld analysis. Homosynthons were observed in three co-crystal systems, while a heterosynthon was observed in five systems. The combination of both homo- and heterosynthon was observed in three cocrystal systems. The phase transformation events were observed in most of the systems. In nine co-crystal systems, the melting points were observed intermediate between those of the API and the coformers.

scholarly journals Crystal structure of di-μ-hydroxido-κ4O:O-bis[bis(acetylacetonato-κ2O,O′)cobalt(III)]

2015 ◽  
Vol 71 (8) ◽  
pp. 983-985 ◽  
Author(s):  
Casseday P. Richers ◽  
Jeffery A. Bertke ◽  
Thomas B. Rauchfuss
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Transition Metal ◽  
Crystal Packing ◽  
Title Complex ◽  
Asymmetric Unit

The dinuclear title complex, [Co2(C5H7O2)4(μ-OH)2] or [Co(acac)2(μ-OH)]2, where acac is acetylacetonate, is centrosymmetric with half of the molecule per asymmetric unit. The molecular structure is a dimer of octahedrally coordinated CoIIIatoms with four O atoms from two chelating acac ligands and two O atoms from bridging hydroxide ligands. The crystal packing features weak C—H...O interactions between neighboring molecules, leading to the formation of chains normal to theacplane. The hydroxide H atoms are not involved in hydrogen bonding because of the bulky acac ligands. This is the first crystal structure reported of a dimeric transition metal bis-acac complex with OH−as the bridging group.

Hydrogen-Bonding Schemes of Galactonic Acid Hydrazide and its Hemihydrate

1997 ◽  
Vol 53 (3) ◽  
pp. 490-497 ◽  
Author(s):  
C. André ◽  
P. Luger ◽  
J.-H. Fuhrhop ◽  
F. Hahn
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Scintillation Counter ◽  
Acid Hydrazide ◽  
Coordination Shell ◽  
Hydroxyl Group ◽  
Free Sugar ◽  
Imaging Plate

The crystal structure of L-galactonic acid hemihydrate was determined using data obtained from an imaging plate detector (Stoe IPDS), whereas a conventional scintillation counter was used for the elucidation of the crystal structure of anhydrous D-galactonic acid. The H atom of the terminal hydroxyl group of the water-free sugar participates only in an intramolecular hydrogen bond with the preterminal O atom. This hydrogen bond is part of an antidromic hydrogen-bonding cycle. The hydrogen-bonding scheme of the hemihydrate is very intricate due to the occurrence of two independent molecules and the incorporated water, whose coordination shell can be described by a distorted tetrahedron. One of the hydrogen-bond chains observed in the structure of the hemihydrate is infinite, forming a spiral running in the a direction. The crystal packing of both compounds displays a herringbone arrangement. However, the tilt angle between molecules in different herringbone halves is by far smaller in the structure of the hydrated sugar than in the water-free compound (~ 60 versus 96°).

scholarly journals (η6-Benzene)(carbonato-κ2O,O′)[dicyclohexyl(naphthalen-1-ylmethyl)phosphane-κP]ruthenium(II) chloroform trisolvate

2014 ◽  
Vol 70 (7) ◽  
pp. m272-m273
Author(s):  
Saravanan Gowrisankar ◽  
Helfried Neumann ◽  
Anke Spannenberg ◽  
Matthias Beller
Keyword(s):  
Hydrogen Bonding ◽  
Metal Complex ◽  
Room Temperature ◽  
Crystal Packing ◽  
The Other ◽  
Asymmetric Unit ◽  
Carbonate Group ◽  
Acta Cryst ◽  
Hydrogen Bonding Interactions ◽  
Solvent Molecules

The title compound, [Ru(CO3)(η6-C6H6){(C6H11)2P(CH2C10H7)}]·3CHCl3, was synthesized by carbonation of [RuCl2(η6-C6H6){(C6H11)2P(CH2C10H7)}] with NaHCO3in methanol at room temperature. The RuIIatom is surrounded by a benzene ligand, a chelating carbonate group and a phosphane ligand in a piano-stool configuration. The crystal packing is consolidated by C—H...O and C—H...Cl hydrogen-bonding interactions between adjacent metal complexes and between the complexes and the solvent molecules. The asymmetric unit contains one metal complex and three chloroform solvent molecules of which only one was modelled. The estimated diffraction contributions of the other two strongly disordered chloroform solvent molecules were substracted from the observed diffraction data using the SQUEEZE procedure inPLATON[Spek (2009).Acta Cryst.D65, 148–155].

Crystal structure and hydrogen bonding in the hydrated cocrystalline salt tryptaminium–3,5-dinitrobenzoate–quinoline–water (3/3/2/2)

2016 ◽  
Vol 72 (10) ◽  
pp. 738-742 ◽  
Author(s):  
Daniel E. Lynch ◽  
Graham Smith ◽  
Tony D. Keene ◽  
Peter N. Horton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Ternary Systems ◽  
Causative Factor ◽  
Asymmetric Unit ◽  
One Dimensional ◽  
Solvent Molecules ◽  
Ring Centroid ◽  
Low Symmetry

The study of ternary systems is interesting because it introduces the concept of molecular preference/competition into the system where one molecule may be displaced because the association between the other two is significantly stronger. Current definitions of a tertiary system indicate that solvent molecules are excluded from the molecule count of the system and some of the latest definitions state that any molecule that is not a solid in the parent form at room temperature should also be excluded from the molecule count. In the structure of the quinoline adduct hydrate of tryptaminium 3,5-dinitrobenzoate, 3C10H13N2+·3C7H3N2O6−·2C9H7N·2H2O, the asymmetric unit comprises multiple cation and anion species which are conformationally similar among each type set. In the crystal, a one-dimensional hydrogen-bonded supramolecular structure is generated through extensive intra- and inter-unit aminium N—H...O and N—H...N, and water O—H...O hydrogen bonds. Within the central-core hydrogen-bonding associations, conjoined cyclicR44(10),R53(10) andR44(12) motifs are generated. The unit is expanded into a one-dimensional column-like polymer extending along [010]. Present also in the crystal packing of the structure are a total of 19 π–π interactions involving both cation, anion and quinoline species [ring-centroid separation range = 3.395 (3)–3.797 (3) Å], as well as a number of weak C—H...O hydrogen-bonding associations. The presence of the two water molecules in the crystal structure is considered to be the principal causative factor in the low symmetry of the asymmetric unit.

scholarly journals Bis(acetato-κO)bis(4,5-dimethylbenzene-1,2-diamine-κN)zinc

2012 ◽  
Vol 68 (8) ◽  
pp. m1040-m1040 ◽  
Author(s):  
David K. Geiger
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Rotation Axis ◽  
Asymmetric Unit

The structure of the title compound, [Zn(CH3COO)2(C8H12N2)2], has one half molecule in the asymmetric unit. The ZnIIatom is situated on a twofold rotation axis and is tetrahedrally coordinated by two N and two O atoms. The crystal packing displays intermolecular N—H...O hydrogen bonds and intramolecular N—H...O and N—H...N hydrogen bonding.

scholarly journals trans-Bis(dimethyl sulfoxide-κO)bis(3-nitrobenzohydroxamato-κ2 O,O′)zinc(II)

IUCrData ◽  
2019 ◽  
Vol 4 (7) ◽  
Author(s):  
Bruna Lisboa Gonçalves ◽  
Samantha Oliveira Monteiro ◽  
Roberta Cargnelutti ◽  
Juliano Rosa de Menezes Vicenti
Keyword(s):  
Hydrogen Bonding ◽  
Dimethyl Sulfoxide ◽  
Single Crystals ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Title Complex ◽  
Dmso Solution ◽  
Asymmetric Unit ◽  
Dimensional Crystal

Single crystals of the title complex, [Zn(C7H5N2O4)2(C2H6OS)2] or [Zn(NBZH)2(DMSO)2], were isolated from a dimethyl sulfoxide (DMSO) solution containing [Zn(NBZH)2]·2H2O (NBZH = 3-nitrobenzohydroxamate anion). The asymmetric unit comprises of one O,O′-chelating NBZH anion, one O-bound DMSO ligand and one zinc(II) cation localized on an inversion centre. The three-dimensional crystal packing includes N—H...O and C—H...O hydrogen bonding, as well as O...H and H...H contacts identified by Hirshfeld isosurface analysis.

scholarly journals Crystal structure and Hirshfeld surface analysis of 1-[(E)-2-(5-chloro-2-hydroxyphenyl)hydrazin-1-ylidene]naphthalen-2(1H)-one

2021 ◽  
Vol 77 (6) ◽  
pp. 672-676
Author(s):  
Hassiba Bougueria ◽  
Souheyla Chetioui ◽  
Mohammed Abdellatif Bensegueni ◽  
Jean-Pierre Djukic ◽  
Nesrine Benarous
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Surface Analysis ◽  
Crystal Packing ◽  
Coupling Reaction ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Hydroxyl Group ◽  
Asymmetric Unit ◽  
Compound C

The title compound, C16H11ClN2O2, was obtained by diazotization of 2-amino-4-chlorophenol followed by a coupling reaction with β-naphthol. There are two molecules (A and B) in the asymmetric unit. The crystal structure features only one type of intermolecular interaction, that is strong hydrogen bonds involving the hydroxyl group. The naphthol and phenol fragments attached to the C=N—N— moiety exhibit an s-trans conformation. In addition, those fragments are almost coplanar, subtending a dihedral angle of 13.11 (2)° in molecule A and 10.35 (2)° in molecule B. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (32.1%), C...H/H...C (23.1%), Cl...H/H...Cl (15.2%), O...H/H...O (12.8%) and C...C (9%) contacts.

scholarly journals Crystal structure of 8-(4-methylphenyl)-2′-deoxyadenosine hemihydrate

2018 ◽  
Vol 74 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ajaykumar V. Ardhapure ◽  
Yogesh S. Sanghvi ◽  
Yulia Borozdina ◽  
Anant Ramakant Kapdi ◽  
Carola Schulzke
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Title Compound ◽  
Crystal Packing ◽  
The Other ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Solvent Water ◽  
Independent Molecules

In the asymmetric unit, equalling the unit cell (triclinic,P1,Z= 1), two molecules of the title compound, 8-(4-methylphenyl)-D-2′-deoxyadenosine, C17H19N5O3, are present, with distinct conformations of the two sugar moieties, together with one solvent water molecule. All three ribose O atoms are involved in hydrogen bonding and the crystal packing is largely determined by hydrogen-bonding or hydrogen–heteroatom interactions (O—H...O, O—H...N, N—H...O, C—H...O and C—H...N) with one independent molecule directly linked to four neighbouring molecules and the other molecule directly linked to six neighbouring molecules. The two independent molecules of the asymmetric unit display three weak intramolecular C—H-to-heteroatom contacts, two of which are very similar despite the different conformations of the deoxyribosyl moieties. The aromatic ring systems of both molecules are in proximity to each other and somehow aligned, though not coplanar. The absolute structures of the two molecules were assumed with reference to the reactant 8-bromo-D-2′-deoxyadenosine as they could not be determined crystallographically.

A Comparison of the Enamino Carbonyl Conjugation Efficiency for Hydrogen Bonding Formation in Pyridone and Dihydropyridone Systems

2000 ◽  
Vol 55 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Teresa Borowiak ◽  
Irena Wolska ◽  
Artur Korzański ◽  
Wolfgang Milius ◽  
Wolfgang Schnick ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Steric Hindrance ◽  
Crystal Packing ◽  
Intermolecular Hydrogen Bond ◽  
Asymmetric Unit ◽  
Intermolecular Hydrogen Bonds

The crystal structures of two compounds containing enaminone heterodiene systems and forming intermolecular hydrogen bonds N-H·O are reported: 1) 3-ethoxycarbonyl-2-methyl-4-pyridone (hereafter ETPY) and 2) 3-ethoxycarbonyl-2-phenyl-6-methoxycarbonyl-5,6-di-hydro-4-pyridone (hereafter EPPY). The crystal packing is controlled by intermolecular hydro­ gen bonds N-H·O = C connecting the heteroconjugated enaminone groups in infinite chains. In ETPY crystals the intermolecular hydrogen bond involves the heterodienic pathway with the highest π-delocalization that is effective for a very short N·O distance of 2.701(9) Å (average from two molecules in the asymmetric unit). Probably due to the steric hindrance, the hydrogen bond in EPPY is formed following the heterodienic pathway that involves the ester C = O group, although π-delocalization along this pathway is less than that along the pyridone-part pathway resulting in a longer N·O distance of 2.886(3) Å

scholarly journals Crystal structure of (E)-1-methyl-2-[2-(2-methoxphenyl)ethenyl]-4-nitro-1H-imidazole

2014 ◽  
Vol 70 (9) ◽  
pp. o966-o967
Author(s):  
Hayette Alliouche ◽  
Abdelmalek Bouraiou ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Ali Belfaitah
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Dimensional Network

In the asymmetric unit of the title compound, C13H13N3O3, the 2-(2-methoxphenyl)ethenyl unit is connected to the methyl-nitroimidazole 1-methyl-4-nitro-1H-imidazole moiety. The molecule is quasi-planar and the planes of the two rings form a dihedral angle of 0.92 (11)°. The crystal packing can be described as layers parallel to the (011) plane, stabilized by intermolecular C—H...O hydrogen bonding, resulting in the formation of an infinite three-dimensional network linking these layers. Strong π–π stacking interactions are observed,viz.benzene–benzene, imidazole–imidazole and benzene–imidazole rings, with centroid–centroid distances of 3.528 (2), 3.457 (2) and 3.544 (2) Å, respectively. Intensity statistics indicated twinning by non-merohedry, with refined weighs of the twin components of 0.3687:0.6313.

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