Cocrystals of 5-fluorocytosine. I. Coformers with fixed hydrogen-bonding sites

2012 ◽  
Vol 68 (4) ◽  
pp. 431-443 ◽  
Author(s):  
Maya Tutughamiarso ◽  
Guido Wagner ◽  
Ernst Egert
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Antiviral Drug ◽  
The Other ◽  
Receptor Interaction ◽  
Dimer Formation ◽  
Hydrogen Bonding Interactions ◽  
Donor Acceptor ◽  
Drug Receptor ◽  
Drug Receptor Interaction

The antifungal drug 5-fluorocytosine (4-amino-5-fluoro-1,2-dihydropyrimidin-2-one) was cocrystallized with five complementary compounds in order to better understand its drug–receptor interaction. The first two compounds, 2-aminopyrimidine (2-amino-1,3-diazine) and N-acetylcreatinine (N-acetyl-2-amino-1-methyl-5H-imidazol-4-one), exhibit donor–acceptor sites for R 2 2(8) heterodimer formation with 5-fluorocytosine. Such a heterodimer is observed in the cocrystal with 2-aminopyrimidine (I); in contrast, 5-fluorocytosine and N-acetylcreatinine [which forms homodimers in its crystal structure (II)] are connected only by a single hydrogen bond in (III). The other three compounds 6-aminouracil (6-amino-2,4-pyrimidinediol), 6-aminoisocytosine (2,6-diamino-3H-pyrimidin-4-one) and acyclovir [acycloguanosine or 2-amino-9-[(2-hydroxyethoxy)methyl]-1,9-dihydro-6H-purin-6-one] possess donor–donor–acceptor sites; therefore, they can interact with 5-fluorocytosine to form a heterodimer linked by three hydrogen bonds. In the cocrystals with 6-aminoisocytosine (Va)–(Vd), as well as in the cocrystal with the antiviral drug acyclovir (VII), the desired heterodimers are observed. However, they are not formed in the cocrystal with 6-aminouracil (IV), where the components are connected by two hydrogen bonds. In addition, a solvent-free structure of acyclovir (VI) was obtained. A comparison of the calculated energies released during dimer formation helped to rationalize the preference for hydrogen-bonding interactions in the various cocrystal structures.

A Neutral Donor-Acceptor p-Stack: Solid-State Structures of 1 : 1 Pyromellitic Diimide-Dialkoxynaphthalene Cocrystals

1997 ◽  
Vol 50 (5) ◽  
pp. 439 ◽  
Author(s):  
Darren G. Hamilton ◽  
Daniel E. Lynch ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Neutral Donor ◽  
Hydrogen Bonding Interactions ◽  
Donor And Acceptor ◽  
Structural Preferences ◽  
Donor Acceptor ◽  
Covalently Linked ◽  
Solid State Structures

Pyromellitic diimide forms orange-coloured cocrystals of 1 : 1 stoichiometry with dialkoxynaphthalene derivatives. The solid-state structures of two examples are presented. The cocrystal formed with 2,6-dimethoxynaphthalene presents vertical stacks of alternating π-rich and π-deficient subunits with the long axes of the respective components approximately parallel. Investigation of the packing in the cocrystal also reveals a stabilizing array of hydrogen bonds between the components of adjacent stacks. Cocrystallization with 1,5-[2-(2-hydroxyethoxy)ethoxy]naphthalene, a derivative bearing hydroxy terminated ethyleneoxy chains, gives rise to an altered structural arrangement. Alternating donor- acceptor stacks once again dominate the structure but adopt a geometry where the long axes of the constituents are essentially perpendicular. Hydrogen-bonding interactions result in the formation of continuous non-covalently linked columns of donor and acceptor subunits by linking the terminal hydroxy functions of the naphthalene component to the imide protons. The structural preferences revealed by these solid-state analyses indicate that these complexes are useful prototypes of more complex neutral supramolecular assemblies.

scholarly journals Functional materials based on molecules with hydrogen-bonding ability: applications to drug co-crystals and polymer complexes

2018 ◽  
Vol 5 (6) ◽  
pp. 180564 ◽  
Author(s):  
Kristin M. Hutchins
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Functional Materials ◽  
Polymeric Materials ◽  
Pharmaceutical Compounds ◽  
Multiple Point ◽  
Polymer Complexes ◽  
Design Synthesis ◽  
Hydrogen Bonding Interactions ◽  
Donor Acceptor

The design, synthesis and property characterization of new functional materials has garnered interest in a variety of fields. Materials that are capable of recognizing and binding with small molecules have applications in sensing, sequestration, delivery and property modification. Specifically, recognition of pharmaceutical compounds is of interest in each of the aforementioned application areas. Numerous pharmaceutical compounds comprise functional groups that are capable of engaging in hydrogen-bonding interactions; thus, materials that are able to act as hydrogen-bond receptors are of significant interest for these applications. In this review, we highlight some crystalline and polymeric materials that recognize and engage in hydrogen-bonding interactions with pharmaceuticals or small biomolecules. Moreover, as pharmaceuticals often exhibit multiple hydrogen-bonding sites, many donor/acceptor molecules have been specifically designed to interact with the drug via such multiple-point hydrogen bonds. The formation of multiple hydrogen bonds not only increases the strength of the interaction but also affords unique hydrogen-bonded architectures.

A Brassinosteroid Derivative Useful to Provide More Information About the Importance of the C2 Group in the Brassinosteroid-Receptor Interaction

2002 ◽  
Vol 67 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Carme Brosa ◽  
Marc Amorós ◽  
Esther Vázquez ◽  
Maria Piqué
Keyword(s):  
Hydrogen Bonding ◽  
Biological Activity ◽  
Hydrogen Bonds ◽  
Receptor Interaction ◽  
Receptor Complex ◽  
Activity Evaluation ◽  
Hydrogen Bonding Interactions

Synthesis and biological activity evaluation in the rice lamina inclination test of (22R,23R)-22,23-dihydroxy-5α-stigmasta-2,6-dione (6) and its (22S,23S)-diastereoisomer 7 is described. The activity of such compounds is discussed in terms of their ability to form hydrogen bonds by means of GRID maps. The activity elicited by 6 reinforces our idea that an oxygenated function at C3 in a brassinosteroid is more important for biological activity than that at C2. The results also suggest that the 2α-OH of brassinosteroids could act as an acceptor in the putative hydrogen bonding interactions in the brassinosteroid-receptor complex.

Molecular chirality and chiral capsule-type dimer formation of cyclic triamidesvia hydrogen-bonding interactions

2012 ◽  
Vol 48 (40) ◽  
pp. 4809-4811 ◽  
Author(s):  
Noriko Fujimoto ◽  
Mio Matsumura ◽  
Isao Azumaya ◽  
Shizuka Nishiyama ◽  
Hyuma Masu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Dimer Formation ◽  
Molecular Chirality ◽  
Capsule Type ◽  
Hydrogen Bonding Interactions

scholarly journals Two New Polyiodides in the 4,4´-Bipyridinium Diiodide/Iodine System

2012 ◽  
Vol 67 (1) ◽  
pp. 5-10
Author(s):  
Guido J. Reiss ◽  
Martin van Megen
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Complex I ◽  
The Other ◽  
Cyclic Dimer ◽  
Water Molecules ◽  
Spectroscopic Methods ◽  
Halogen Bonds ◽  
One Dimensional ◽  
Hydroiodic Acid

The reaction of bipyridine with hydroiodic acid in the presence of iodine gave two new polyiodide-containing salts best described as 4,4´-bipyridinium bis(triiodide), C10H10N2[I3]2, 1, and bis(4,4´-bipyridinium) diiodide bis(triiodide) tris(diiodine) solvate dihydrate, (C10H10N2)2I2[I3]2 · 3 I2 ·2H2O, 2. Both compounds have been structurally characterized by crystallographic and spectroscopic methods (Raman and IR). Compound 1 is composed of I3 − anions forming one-dimensional polymers connected by interionic halogen bonds. These chains run along [101] with one crystallographically independent triiodide anion aligned and the other triiodide anion perpendicular to the chain direction. There are no classical hydrogen bonds present in 1. The structure of 2 consists of a complex I144− anion, 4,4´-bipyridinium dications and hydrogen-bonded water molecules in the ratio of 1 : 2 : 2. The I144− polyiodide anion is best described as an adduct of two iodide and two triiodide anions and three diiodine molecules. Two 4,4´-bipyridinium cations and two water molecules form a cyclic dimer through N-H· · ·O hydrogen bonds. Only weak hydrogen bonding is found between these cyclic dimers and the polyiodide anions.

scholarly journals 1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydrophenanthrene-1-carboxylic acid

2009 ◽  
Vol 65 (6) ◽  
pp. o1429-o1429
Author(s):  
Zhen-Dong Zhao ◽  
Yu-Xiang Chen ◽  
Yu-Min Wang ◽  
Liang-Wu Bi
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Slash Pine ◽  
Carboxyl Groups ◽  
Isopimaric Acid ◽  
Hydrogen Bonding Interactions ◽  
Cyclohexene Ring

The title compound, also known as isopimaric acid, C20H30O2, was isolated from slash pine rosin. There are two unique molecules in the unit cell. The two cyclohexane rings have classical chair conformations. The cyclohexene ring represents a semi-chair. The molecular conformation is stabilized by weak intramolecular C—H...O hydrogen-bonding interactions. The molecules are dimerized through their carboxyl groups by O—H...O hydrogen bonds, formingR22(8) rings.

Polymorphs of phenazine hexacyanoferrate(II) hydrate: supramolecular isomerism in a 2D hydrogen-bonded network

2021 ◽  
Vol 77 (2) ◽  
pp. 211-218
Author(s):  
Ivica Cvrtila ◽  
Vladimir Stilinović
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
The Other ◽  
Two Dimensional ◽  
Structural Motifs ◽  
Supramolecular Isomerism ◽  
Other Hand ◽  
Π Stacking ◽  
Hydrogen Bonded

The crystal structures of two polymorphs of a phenazine hexacyanoferrate(II) salt/cocrystal, with the formula (Hphen)3[H2Fe(CN)6][H3Fe(CN)6]·2(phen)·2H2O, are reported. The polymorphs are comprised of (Hphen)2[H2Fe(CN)6] trimers and (Hphen)[(phen)2(H2O)2][H3Fe(CN)6] hexamers connected into two-dimensional (2D) hydrogen-bonded networks through strong hydrogen bonds between the [H2Fe(CN)6]2− and [H3Fe(CN)6]− anions. The layers are further connected by hydrogen bonds, as well as through π–π stacking of phenazine moieties. Aside from the identical 2D hydrogen-bonded networks, the two polymorphs share phenazine stacks comprising both protonated and neutral phenazine molecules. On the other hand, the polymorphs differ in the conformation, placement and orientation of the hydrogen-bonded trimers and hexamers within the hydrogen-bonded networks, which leads to different packing of the hydrogen-bonded layers, as well as to different hydrogen bonding between the layers. Thus, aside from an exceptional number of symmetry-independent units (nine in total), these two polymorphs show how robust structural motifs, such as charge-assisted hydrogen bonding or π-stacking, allow for different arrangements of the supramolecular units, resulting in polymorphism.

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