scholarly journals Co-crystallization of a neutral molecule and its zwitterionic tautomer: structure and Hirshfeld surface analysis of 5-methyl-4-(5-methyl-1H-pyrazol-3-yl)-2-phenyl-2,3-dihydro-1H-pyrazol-3-one 5-methyl-4-(5-methyl-1H-pyrazol-2-ium-3-yl)-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-1-ide monohydrate

Author(s):  
Abdullah M. Asiri ◽  
Khalid A. H. Alzahrani ◽  
Hassan M. Faidallah ◽  
Khalid A. Alamry ◽  
Mukesh M. Jotani ◽  
...  

The title compound, 2C14H14N4O·H2O, comprises a neutral molecule containing a central pyrazol-3-one ring flanked by an N-bound phenyl group and a C-bound 5-methyl-1H-pyrazol-3-yl group (at positions adjacent to the carbonyl substituent), its zwitterionic tautomer, whereby the N-bound proton of the central ring is now resident on the pendant ring, and a water molecule of crystallization. Besides systematic variations in geometric parameters, the two independent organic molecules have broadly similar conformations, as seen in the dihedral angle between the five-membered rings [9.72 (9)° for the neutral molecule and 3.32 (9)° for the zwitterionic tautomer] and in the dihedral angles between the central and pendant five-membered rings [28.19 (8) and 20.96 (8)° (neutral molecule); 11.33 (9) and 11.81 (9)°]. In the crystal, pyrazolyl-N—H...O(carbonyl) and pyrazolium-N—H...N(pyrazolyl) hydrogen bonds between the independent organic molecules give rise to non-symmetric nine-membered {...HNNH...NC3O} and {...HNN...HNC3O} synthons, which differ in the positions of the N-bound H atoms. These aggregates are connected into a supramolecular layer in the bc plane by water-O—H...N(pyrazolide), water-O—H...O(carbonyl) and pyrazolyl-N—H...O(water) hydrogen bonding. The layers are linked into a three-dimensional architecture by methyl-C—H...π(phenyl) interactions. The different interactions, in particular the weaker contacts, formed by the organic molecules are clearly evident in the calculated Hirshfeld surfaces, and the calculated electrostatic potentials differentiate the tautomers.

Author(s):  
Sabina Yasmin ◽  
Saswata Rabi ◽  
Avijit Chakraborty ◽  
Huey Chong Kwong ◽  
Edward R. T. Tiekink ◽  
...  

The title CuII macrocyclic complex salt tetrahydrate, [Cu(C22H46N6O2)](C2H3O2)2·4H2O, sees the metal atom located on a centre of inversion and coordinated within a 4 + 2 (N4O2) tetragonally distorted coordination geometry; the N atoms are derived from the macrocycle and the O atoms from weakly associated [3.2048 (15) Å] acetate anions. Further stability to the three-ion aggregate is provided by intramolecular amine-N—H...O(carboxylate) hydrogen bonds. Hydrogen bonding is also prominent in the molecular packing with amide-N—H...O(amide) interactions, leading to eight-membered {...HNCO}2 synthons, amide-N—H...O(water), water-O—H...O(carboxylate) and water-O—H...O(water) hydrogen bonds featuring within the three-dimensional architecture. The calculated Hirshfeld surfaces for the individual components of the asymmetric unit differentiate the water molecules owing to their distinctive supramolecular association. For each of the anion and cation, H...H contacts predominate (50.7 and 65.2%, respectively) followed by H...O/O...H contacts (44.5 and 29.9%, respectively).


Author(s):  
Sabrina Syed ◽  
Siti Nadiah Abdul Halim ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink

The title 2:1 co-crystal, 2C7H5NO4·C14H14N4O2, in which the complete diamide molecule is generated by crystallographic inversion symmetry, features a three-molecule aggregate sustained by hydroxyl-O—H...N(pyridyl) hydrogen bonds. Thep-nitrobenzoic acid molecule is non-planar, exhibiting twists of both the carboxylic acid and nitro groups, which form dihedral angles of 10.16 (9) and 4.24 (4)°, respectively, with the benzene ring. The diamide molecule has a conformation approximating to a Z shape, with the pyridyl rings lying to either side of the central, almost planar diamide residue (r.m.s. deviation of the eight atoms being 0.025 Å), and forming dihedral angles of 77.22 (6)° with it. In the crystal, three-molecule aggregates are linked into a linear supramolecular ladder sustained by amide-N—H...O(nitro) hydrogen bonds and orientated along [10-4]. The ladders are connected into a double layerviapyridyl- and benzene-C—H...O(amide) interactions, which, in turn, are connected into a three-dimensional architectureviaπ–π stacking interactions between pyridyl and benzene rings [inter-centroid distance = 3.6947 (8) Å]. An evaluation of the Hirshfeld surfaces confirm the importance of intermolecular interactions involving oxygen atoms as well as the π–π interactions.


Author(s):  
Ming Yueh Tan ◽  
Huey Chong Kwong ◽  
Karen A. Crouse ◽  
Thahira B. S. A. Ravoof ◽  
Edward R. T. Tiekink

The title zinc bis(thiosemicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetrahedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethylene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitrobenzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitrobenzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supramolecular chain along the b-axis direction features amine-N—H...O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C—H...O(nitro) and π(chelate ring)–π(phenyl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C—H...O(nitro) and nitro-O...π(phenyl) interactions.


IUCrData ◽  
2021 ◽  
Vol 6 (11) ◽  
Author(s):  
C. Selva Meenatchi ◽  
S. Athimoolam ◽  
J. Suresh ◽  
S. Raja Rubina ◽  
R. Ranjith Kumar ◽  
...  

In the title compound, C20H15ClN2O, the non-aromatic six-membered ring adopts a distorted envelope conformation with methylene-C atom nearest to the five-membered ring being the flap atom. The dihedral angle between the phenyl and chlorobenzene rings is 74.5 (1)°. The heterocyclic ring forms dihedral angles of 37.9 (1) and 64.3 (1)° with the phenyl and chlorobenzene rings, respectively. In the crystal, weak C—H...O interactions feature predominantly within the three-dimensional architecture. The intermolecular interactions are further analysed with the calculation of the Hirshfeld surfaces highlighting the prominent role of C—H...O interactions, along with H...H (36.8%) and C...H/H...C (26.5%) contacts.


Author(s):  
Wissem Zemamouche ◽  
Rima Laroun ◽  
Noudjoud Hamdouni ◽  
Ouarda Brihi ◽  
Ali Boudjada ◽  
...  

The title compound, C11H9NO3, contains an isoxazole and a hydroxybenzylidene ring, which are inclined to each another by 3.18 (8)°. There is an intramolecular C—H...O contact forming an S(7) ring. In the crystal, molecules stack head-to-tail in columns along the b-axis direction, linked by offset π–π interactions [intercentroid distances of 3.676 (1) and 3.723 (1) Å]. The columns are linked by O—H...O and O—H...N hydrogen bonds, forming layers parallel to the ab plane. The layers are linked by C—H...O hydrogen bonds, forming a supramolecular three-dimensional framework. An analysis of the Hirshfeld surfaces points to the importance of the O—H...O and O—H...N hydrogen bonding in the packing mechanism of the crystal structure.


Author(s):  
Sang Loon Tan ◽  
Edward R. T. Tiekink

The asymmetric unit of the title 1:2 co-crystal, C14H14N4O2·2C7H5ClO2, comprises two half molecules of oxalamide (4 LH2), as each is disposed about a centre of inversion, and two molecules of 4-chlorobenzoic acid (CBA), each in general positions. Each 4 LH2 molecule has a (+)antiperiplanar conformation with the pyridin-4-yl residues lying to either side of the central, planar C2N2O2 chromophore with the dihedral angles between the respective central core and the pyridyl rings being 68.65 (3) and 86.25 (3)°, respectively, representing the major difference between the independent 4 LH2 molecules. The anti conformation of the carbonyl groups enables the formation of intramolecular amide-N—H...O(amide) hydrogen bonds, each completing an S(5) loop. The two independent CBA molecules are similar and exhibit C6/CO2 dihedral angles of 8.06 (10) and 17.24 (8)°, indicating twisted conformations. In the crystal, two independent, three-molecule aggregates are formed via carboxylic acid-O—H...N(pyridyl) hydrogen bonding. These are connected into a supramolecular tape propagating parallel to [100] through amide-N—H...O(amide) hydrogen bonding between the independent aggregates and ten-membered {...HNC2O}2 synthons. The tapes assemble into a three-dimensional architecture through pyridyl- and methylene-C—H...O(carbonyl) and CBA-C—H...O(amide) interactions. As revealed by a more detailed analysis of the molecular packing by calculating the Hirshfeld surfaces and computational chemistry, are the presence of attractive and dispersive Cl...C=O interactions which provide interaction energies approximately one-quarter of those provided by the amide-N—H...O(amide) hydrogen bonding sustaining the supramolecular tape.


Author(s):  
Ming Yueh Tan ◽  
Karen A. Crouse ◽  
Thahira B. S. A. Ravoof ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink

Two independent molecules (AandB) comprise the asymmetric unit of the title compound, C18H21N3O3. The urea moiety is disubstituted with one amine being linked to a phenyl ring, which is twisted out of the plane of the CN2O urea core [dihedral angles = 25.57 (11) (A) and 29.13 (10)° (B)]. The second amine is connected to an imine (Econformation), which is linked in turn to an ethane bridge that links a disubstituted benzene ring. Intramolecular amine-N—H...N(imine) and hydroxyl-O—H...O(methoxy) hydrogen bonds closeS(5) loops in each case. The molecules have twisted conformations with the dihedral angles between the outer rings being 38.64 (81) (A) and 48.55 (7)° (B). In the crystal, amide-N—H...O(amide) hydrogen bonds link the moleculesAandB viaan eight-membered {...HNCO}2synthon. Further associations between molecules, leading to supramolecular layers in theacplane, are hydrogen bonds of the type hydroxyl-O—H...N(imine) and phenylamine-N—H...O(methoxy). Connections between layers, leading to a three-dimensional architecture, comprise benzene-C—H...O(hydroxy) interactions. A detailed analysis of the calculated Hirshfeld surfaces shows moleculesAandBparticipate in very similar intermolecular interactions and that any variations relate to conformational differences between the molecules.


2014 ◽  
Vol 70 (4) ◽  
pp. o402-o403
Author(s):  
Hadi D. Arman ◽  
Trupta Kaulgud ◽  
Edward R. T. Tiekink

The sulfathiazole molecule in the title 1:1 co-crystal, C9H9N3O2S2·C18H12N6, adopts an approximate L-shape [dihedral angle between the five- and six-membered rings = 86.20 (9)°] and features an intramolecular hypervalent S...O interaction [2.8666 (15) Å]. Overall, the triazine molecule has the shape of a disk as the pendant pyridine rings are relatively close to coplanar with the central ring [dihedral angles = 18.35 (9), 6.12 (9) and 4.67 (9)°]. In the crystal packing, a linear supramolecular chain aligned along [01-1] is formed as a result of amino–pyridyl N—H...N hydrogen bonding withsyn-disposed pyridyl molecules of one triazine, and amine–pyridyl N—H...N hydrogen bonding with the third pydridyl ring of a second triazine molecule. A three-dimensional architecture arises as the chains are connected by C—H...O interactions.


2018 ◽  
Vol 74 (11) ◽  
pp. 1553-1560
Author(s):  
Ligia R. Gomes ◽  
Marcus V. N. de Souza ◽  
Cristiane F. Da Costa ◽  
James L. Wardell ◽  
John Nicolson Low

The crystal structures of four (E)-methoxybenzaldehyde oxime derivatives, namely (2-methoxybenzaldehyde oxime, 1, 2,3-dimethoxybenzaldehyde oxime, 2, 4-dimethoxybenzaldehyde oxime, 3, and 2,5-dimethoxybenzaldehyde oxime, 4, are discussed. The arrangements of the 2-methoxy group and the H atom of the oxime unit are s-cis in compounds 1–3, but in both independent molecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two molecules in 4, involving the orientations of the 2- and 5-methoxy groups. The primary intermolecular O—H(oxime)...O(hydroxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O—H(oxime)...O(hydroxy) hydrogen bonds generate symmetric R 2 2(6) dimers. A more complex dimer is generated in 4 from the O—H(oxime)...O(hydroxy) and C—H(2-methoxy)...O(hydroxy) hydrogen bonds. In all cases, further interactions, C—H...O and C—H...π or π–π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.


Author(s):  
Rajesh Kumar ◽  
Shafqat Hussain ◽  
Khalid M. Khan ◽  
Shahnaz Perveen ◽  
Sammer Yousuf

In the title compound, C16H10Cl2N2O2S, the dihedral angles formed by the chloro-substituted benzene rings with the central oxadiazole ring are 6.54 (9) and 6.94 (8)°. In the crystal, C—H...N hydrogen bonding links the molecules into undulating ribbons running parallel to thebaxis. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are the H...C (18%), H...H (17%), H...Cl (16.6%), H...O (10.4%), H...N (8.9%) and H...S (5.9%) interactions.


Sign in / Sign up

Export Citation Format

Share Document