scholarly journals Supramolecular hydrogen-bonding patterns of co-crystals containing the active pharmaceutical ingredient (API) phloroglucinol andN-heterocycles

Author(s):  
Aleksandar Cvetkovski ◽  
Valerio Bertolasi ◽  
Valeria Ferretti

The active pharmaceutical ingredient phloroglucinol (PHL) has been taken as an illustrative molecule to explore the intermolecular interactions which can be established with other molecular entities to build PHL pharmaceutical co-crystals. The crystal structures of five newly synthesized co-crystals are reported, where PHL is crystallized withN-heterocycles, namely 2-hydroxy-6-methylpyridine (1), 2,4-dimethyl-6-hydroxypyrimidine (2), 4-phenylpyridine (3), 2-hydroxypyridine (4) and 2,3,5,6-tetramethylpyrazine (5). The structural characteristics of these co-crystals, as far as the hydrogen-bonding networks and the crystalline architectures are concerned, are strongly dependent on the chemical features of the coformer molecules, as well as on their size and shape. A detailed analysis of the intermolecular interactions established in all the PHL co-crystals of known structures has allowed the recognition of some regularities in the packing modes that can be useful in the design of new supramolecular adducts forming predictable structural motifs.

Author(s):  
Ivica Cvrtila ◽  
Vladimir Stilinović

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.


2014 ◽  
Vol 70 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Ernst Egert

The preferred hydrogen-bonding patterns in the crystal structures of 5-propyl-2-thiouracil, C7H10N2OS, (I), 5-methoxy-2-thiouracil, C5H6N2O2S, (II), 5-methoxy-2-thiouracil–N,N-dimethylacetamide (1/1), C5H6N2O2S·C4H9NO, (IIa), 5,6-dimethyl-2-thiouracil, C6H8N2OS, (III), 5,6-dimethyl-2-thiouracil–1-methylpyrrolidin-2-one (1/1), C6H8N2OS·C5H9NO, (IIIa), 5,6-dimethyl-2-thiouracil–N,N-dimethylformamide (2/1), 2C6H8N2OS·C3H7NO, (IIIb), 5,6-dimethyl-2-thiouracil–N,N-dimethylacetamide (2/1), 2C6H8N2OS·C4H9NO, (IIIc), and 5,6-dimethyl-2-thiouracil–dimethyl sulfoxide (2/1), 2C6H8N2OS·C2H6OS, (IIId), were analysed. All eight structures containR22(8) patterns. In (II), (IIa), (III) and (IIIa), they are formed by two N—H...S hydrogen bonds, and in (I) by alternating pairs of N—H...S and N—H...O hydrogen bonds. In contrast, the structures of (IIIb), (IIIc) and (IIId) contain `mixed'R22(8) patterns with one N—H...S and one N—H...O hydrogen bond, as well asR22(8) motifs with two N—H...O hydrogen bonds.


2021 ◽  
Vol 77 (10) ◽  
pp. 615-620
Author(s):  
Duyen N. K. Pham ◽  
Zachary S. Belanger ◽  
Andrew R. Chadeayne ◽  
James A. Golen ◽  
David R. Manke

The crystal structures of the hydrochloride salts of nine substituted tryptamines, namely, 1-methyltryptammonium chloride, C11H15N2 +·Cl−, (1), 2-methyl-1-phenyltryptammonium chloride, C17H19N2 +·Cl−, (2), 5-methoxytryptammonium chloride, C11H15N2O+·Cl−, (3), 5-bromotryptammonium chloride, C10H12BrN2 +·Cl−, (4), 5-chlorotryptammonium chloride, C10H12ClN2 +·Cl−, (5), 5-fluorotryptammonium chloride, C10H12FN2 +·Cl−, (6), 5-methyltryptammonium chloride, C11H15N2 +·Cl−, (7), 6-fluorotryptammonium chloride, C10H12FN2 +·Cl−, (8), and 7-methyltryptammonium chloride, C11H15N2 +·Cl−, (9), are reported. The seven tryptamines with N—H indoles, (3)–(9), show very similar structures, with N—H...Cl hydrogen-bonding networks forming two-dimensional sheets in the crystals. These sheets are combinations of R 4 2(8) and R 4 2(18) rings, and C 2 1(4) and C 2 1(9) chains. Substitution at the indole N atom reduces the dimensionality of the hydrogen-bonding network, with compounds (1) and (2) demonstrating one-dimensional chains that are a combination of different rings and parallel chains.


1999 ◽  
Vol 54 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Christian Hollatz ◽  
Annette Schier ◽  
Hubert Schmidbaur

Diphenyl(2-hydroxy-phenyl)phosphine was introduced as a ligand for gold(I) halides and pentafluorophenyl gold(I) in order to probe the interplay of intra- and intermolecular interactions based on aurophilic (Au· · ·Au) and hydrogen bonding. 1:1 complexes of the type Ph2(2-HO-C6H4)P-Au-X with X = Cl, Br, C6F5 have been prepared and characterized by analytical and spectroscopic data. The crystal structure of the chloro complex (1) has been determined. In the lattice the molecules form dimers through O-H· · ·Cl hydrogen bonds. Au· · ·Au contacts are ruled out by steric congestion. Reaction of 1 with triethylamine yields a 1:1 adduct with O-H· · ·NEt3 hydrogen bonding. The trimethylsilyl ether of the title ligand also forms 1:1 complexes with AuCl, AuBr, Aul, and AuC6F5. The crystal structures of the chloro (5) and iodo (7) compound have been determined. In both cases the lattices are built from monomers which show only minor differences in their conformations. The silylether groups are not acting as intra- or intermolecular donor functions to the gold atoms.


Author(s):  
Haruki Sugiyama

The crystal structures of two salt crystals of 2,2-bis(4-methylphenyl)hexafluoropropane (Bmphfp) with amines, namely, dipyridinium 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoic acid, 2C5H6N+·C17H8F6O4 2−·C17H10F6O4, (1), and a monohydrated ethylenediammonium salt ethane-1,2-diaminium 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate monohydrate, C2H10N2 2+·C17H8F6O4 2−·H2O, (2), are reported. Compounds 1 and 2 crystallize, respectively, in space group P21/c with Z′ = 2 and in space group Pbca with Z′ = 1. The crystals of compound 1 contain neutral and anionic Bmphfp molecules, and form a one-dimensional hydrogen-bonded chain motif. The crystals of compound 2 contain anionic Bmphfp molecules, which form a complex three-dimensional hydrogen-bonded network with the ethylenediamine and water molecules.


Author(s):  
Marek Daszkiewicz ◽  
Agnieszka Mielcarek

Crystal structures of (H2m4na)NO3(1), (H2m4na)HSO4(2), (H2m4na)2SiF6(3) and (H2m4na)2SiF6·2H2O (4), where 2m4na = 2-methyl-4-nitroaniline, are presented. Two layers of interactions occur in the structures, N—H...O/F hydrogen bonds and interactions with the nitro group. Although diverse, hydrogen-bonding patterns are compared with each other by means of interrelations among elementary graph-set descriptors and descriptors of hydrogen-bonding patterns. Using mathematical relations, the gradual expansion of the ring patterns was shown in the crystal structures. Parallel and perpendicular arranged nitro groups form weak π(N)NO2...π(O)NO2and π(N)NO2...ONO2interactions, respectively. The πNO2...πringinteraction has an impact to the stabilization of parallel oriented nitro groups. Generally, weak interactions constructed by the nitro group occur in the studied crystals as follows: π(N)NO2...π(O)NO2, πring...πring, C—H...O (1); π(N)NO2...π(O)NO2, π(N)NO2...ONO2(2); π(N)NO2...π(O)NO2, π(N)NO2...ONO2(3); C—H...O (4).


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