Crystal structure and energetic features of the cocrystal of carbamazepine with 3,5-dinitrobenzoic acid

2019 ◽  
Vol 75 (8) ◽  
pp. 1150-1156 ◽  
Author(s):  
Sylwia Pawlędzio ◽  
Damian Trzybiński ◽  
Krzysztof Woźniak

The synthesis and detailed description of the crystal structure and energetic features of the 1:1 cocrystal of carbamazepine (5H-dibenzo[b,f]azepine-5-carboxamide, CBZ) with 3,5-dinitrobenzoic acid (35DNBA), i.e. C15H12N2O·C7H4N2O6, are reported. The CBZ and 35DNBA molecules are packed in alternately arranged layers. Two characteristic R 2 2(8) and R 2 2(16) hydrogen-bond ring motifs have been found. The supramolecular architecture, besides the network of hydrogen bonds, is also stabilized by numerous C—H...π, C=O...π, N—O...π, N—O...C and C=O...N weak intermolecular contacts involving neighbouring molecules in the crystal network. Identified interactions have been discussed in detail on the basis of a structural and energetic analysis. The latter approach, performed using the Pixel and CrystalExplorer programs, yielded additional information about the lattice energy and energetic landscape of the respective interactions in the crystal of CBZ·3DNBA with the evaluation of electrostatic, polarization, repulsion and dispersion terms.

2006 ◽  
Vol 62 (4) ◽  
pp. 642-650 ◽  
Author(s):  
Harriott Nowell ◽  
Christopher S. Frampton ◽  
Julie Waite ◽  
Sarah L. Price

The commercially available peptide coupling reagent 1-hydroxy-7-azabenzotriazole has been shown to crystallize in two polymorphic forms. The two polymorphs differ in their hydrogen-bonding motif, with form I having an R_2^2(10) dimer motif and form II having a C(5) chain motif. The previously unreported form II was used as an informal blind test of computational crystal structure prediction for flexible molecules. The crystal structure of form II has been successfully predicted blind from lattice-energy minimization calculations following a series of searches using a large number of rigid conformers. The structure for form II was the third lowest in energy with form I found as the global minimum, with the energy calculated as the sum of the ab initio intramolecular energy penalty for conformational distortion and the intermolecular lattice energy which is calculated from a distributed multipole representation of the charge density. The predicted structure was sufficiently close to the experimental structure that it could be used as a starting model for crystal structure refinement. A subsequent limited polymorph screen failed to yield a third polymorphic form, but demonstrated that alcohol solvents are implicated in the formation of the form I dimer structure.


2018 ◽  
Vol 74 (5) ◽  
pp. 534-541 ◽  
Author(s):  
Ammara Shahid ◽  
Ambreen Aziz ◽  
Sajida Noureen ◽  
Maqsood Ahmed ◽  
Sammer Yousuf ◽  
...  

The biologically transformed product of estradiol valerate, namely 3,7α-dihydroxyestra-1,3,5(10)-trien-17-one monohydrate, C18H22O3·H2O, has been investigated using UV–Vis, IR, 1H and 13C NMR spectroscopic techniques, as well as by mass spectrometric analysis. Its crystal structure was determined using single-crystal X-ray diffraction based on data collected at 100 K. The structure was refined using the independent atom model (IAM) and the transferred electron-density parameters from the ELMAM2 database. The structure is stabilized by a network of hydrogen bonds and van der Waals interactions. The topology of the hydrogen bonds has been analyzed by the Bader theory of `Atoms in Molecules' framework. The molecular electrostatic potential for the transferred multipolar atom model reveals an asymmetric character of the charge distribution across the molecule due to a substantial charge delocalization within the molecule. The molecular dipole moment was also calculated, which shows that the molecule has a strongly polar character.


2017 ◽  
Vol 73 (11) ◽  
pp. 1612-1615
Author(s):  
Delia Bautista ◽  
Sergio J. Benitez-Benitez

The binuclear title complex, di-μ-iodido-bis({2-[(benzylamino-κN)methyl]phenyl-κC1}palladium(II)), [Pd2I2(C14H14N)2], was prepared by reaction of [Pd{C6H4(CH2NHCH2Ph)-2}(μ-OAc)]2with NaI. It crystallizes with one discrete molecule in the asymmetric unit. The molecule presents an iodide-bridged dimeric structure with acisoidarrangement with respect to theC,N-cyclopalladated ligands. Both PdIIatoms have a slightly distorted square-planar coordination environment. Weak intermolecular contacts of the type C—H...Pd seem to have a significant influence on the arrangement of the molecules along thebaxis in the crystal.


Author(s):  
Sevgi Kansiz ◽  
Adnan M. Qadir ◽  
Necmi Dege ◽  
Li Yongxin ◽  
Eiad Saif

The reaction of copper(II) sulfatepentahydrate with 2-nitrobenzoic acid and N,N,N′,N′-tetramethylethylenediamine (TMEDA) in basic solution produces the complex bis(2-nitrobenzoato-κO)(N,N,N′,N′-tetramethylethylenediamine-κ2 N,N′)copper(II), [Cu(C7H4NO4)2(C6H16N2)] or [Cu(2-nitrobenzoate)2(tmeda)]. Each carboxylate group of the 2-nitrobenzoate ligand is coordinated by CuII atom in a monodentate fashion and two TMEDA ligand nitrogen atoms are coordinate by the metal center, giving rise to a distorted square-planar coordination environment. In the crystal, metal complexes are linked by centrosymmetric C—H...O hydrogen bonds, forming ribbons via a R 2 2(10) ring motif. These ribbons are linked by further C—H...O hydrogen bonds, leading to two-dimensional hydrogen-bonded arrays parallel to the bc plane. Weak π–π stacking interactions provide additional stabilization of the crystal structure. Hirshfeld surface analysis, dnorm and two-dimensional fingerprint plots were examined to verify the contributions of the different intermolecular contacts within the supramolecular structure. The major interactions of the complex are O...H/H...O (44.9%), H...H (34%) and C...H (14.5%).


1997 ◽  
Vol 52 (8) ◽  
pp. 989-993 ◽  
Author(s):  
B Mertens ◽  
Hk Müller-Buschbaum

Single crystals of Ba2,5Cd11(VO4)9 have been prepared by solid state reactions. The new compound crystallizes with orthorhombic symmetry, space group D142h-Pbcn, a = 20.842(6), b = 13.471(3), c = 11.838(9) Å, Z = 4. The crystal structure is characterized and dominated by CdO6 octahedra and unusual square pyramids of O2- around Cd2+ forming a three-dimensional [Cd11O36] network. The interstices are occupied by V5+ and Ba2+ ions. This results in VO4 tetrahedra and irregular BaO10 polyhedra isolated from each other. Occupation of the barium positions is deficient in agreement with the valence state V5+ and calculations of the coulomb terms of lattice energy.


1997 ◽  
Vol 52 (8) ◽  
pp. 978-980 ◽  
Author(s):  
M Höhling ◽  
W Preetz

The structure of tetraphenylarsonium pentachlorocarbonylosmate(IV), (Ph4As)[OsCl5(CO)], the first example of a halogenocarbonyl complex with osmium in the oxidation state +IV, has been determined at 208 K by single crystal X-ray diffraction: tetragonal, space group P4/n with a = 12.821 , c = 8.084 Å, Z = 2. There are short intermolecular contacts between neighbouring anions along the tetragonal axis c and unusually large displacement ellipsoids of the carbonyl group and the four equatorial Cl ligands arising from a positional disorder of the complex anion. By analogy with a variety of reported structures of the (Ph4As)[RuNCl4] structure type this is attributed to the close packing of the cation sublattice. Compared to other monocarbonylosmates the Os-C bond of 1.94(2) Å is extraordinaryly long while the bond between Os and the trans coordinated Cl ligand of 2.286(3) Å is rather short.


CrystEngComm ◽  
2020 ◽  
Vol 22 (34) ◽  
pp. 5678-5689
Author(s):  
Ewelina Grabias ◽  
Bogdan Tarasiuk ◽  
Anna Dołęga ◽  
Marek Majdan

U(vi) and isothiouronium salts create a strong charge-assisted network of hydrogen bonds and ionic interactions.


2014 ◽  
Vol 70 (a1) ◽  
pp. C667-C667
Author(s):  
Angeles Pulido ◽  
Ming Liu ◽  
Paul Reiss ◽  
Anna Slater ◽  
Sam Chong ◽  
...  

Among microporous materials, there has been an increasing recent interest in porous organic cage (POC) crystals, which can display permanent intrinsic (molecular) and extrinsic (crystal network) porosity. These materials can be used as molecular sieves for gas separation and potential applications as enzyme mimics have been suggested since they exhibit structural response toward guest molecules[1]. Small structural modifications of the initial building blocks of the porous organic molecules can lead to quite different molecular assembly[1]. Moreover, the crystal packing of POCs is based on weak molecular interactions and is less predictable that other porous materials such as MOFs or zeolites.[2] In this contribution, we show that computational techniques -molecular conformational searches and crystal structure prediction- can be successfully used to understand POC crystal packing preferences. Computational results will be presented for a series of closely related tetrahedral imine- and amine-linked porous molecules, formed by [4+6] condensation of aromatic aldehydes and cyclohexyl linked diamines. While the basic cage is known to have one strongly preferred crystal structure, the presence of small alkyl groups on the POC modifies its crystal packing preferences, leading to extensive polymorphism. Calculations were able to successfully identify these trends as well as to predict the structures obtained experimentally, demonstrating the potential for computational pre-screening in the design of POCs within targeted crystal structures. Moreover, the need of accurate molecular (ab initio calculations) and crystal (based on atom-atom potential lattice energy minimization) modelling for computer-guided crystal engineering will be discussed.


CrystEngComm ◽  
2018 ◽  
Vol 20 (26) ◽  
pp. 3728-3740 ◽  
Author(s):  
Naini Bajaj ◽  
Himal Bhatt ◽  
K. K. Pandey ◽  
H. K. Poswal ◽  
A. Arya ◽  
...  

Molecular reorientations result in structural phase transition in trans-PtCl2(PEt3)2 under pressure, leading to a hydrogen bond assisted supramolecular architecture.


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