scholarly journals Hirshfeld Surface Analysis and Energy Framework for Crystals of Quinazoline Methylidene Bridged Compounds

Proceedings ◽  
2020 ◽  
Vol 62 (1) ◽  
pp. 1
Author(s):  
Akmaljon Tojiboev ◽  
Sherzod Zhurakulov ◽  
Ulli Englert ◽  
Ruimin Wang ◽  
Irmgard Kalf ◽  
...  

The crystal structures of 4-(3,4-dimethoxyphenylethylamino)-methylidene-2,3,4,10-tetrahydro-1H-pyrido[2,1-b]-quinazolin-10-one (1) and 4-(3,4-methylene-dioxyphenylethylamino)-methylidene-2,3,4,10-tetrahydro-1H-pyrido[2,1-b]-quina-zolin-10-one hydrochloride (2) were studied by single crystal X-ray diffraction. Their molecular and crystal structures are described in the context of intra- and inter-molecular interactions and of stereoisomerism. The crystallographic study established mixed E, Z configuration about the C4=C12 bond for (1) and E configuration about the C4=C12 bond for (2). For molecular crystals, Hirshfeld surface analyses may provide insight into intermolecular interactions, and energy framework analyses allow one to quantify different contributions to the overall energy. These analyses were performed to pinpoint intermolecular interactions in (1) and (2). According to our results, the molecules are associated with intra- and intermolecular hydrogen bonds, C-H···π and π-stacking interactions. The three-dimensional Hirshfeld surface analyses and two-dimensional fingerprint plots revealed that the structures are dominated by H···H, H···C/C···H and H···O/O···H contacts. The intermolecular energy analysis confirmed a significant contribution of dispersion to the stabilization of molecular packings in (1) and (2).

2019 ◽  
Vol 234 (1) ◽  
pp. 59-71 ◽  
Author(s):  
Ligia R. Gomes ◽  
John N. Low ◽  
Nathasha R. de L. Correira ◽  
Thais C.M. Noguiera ◽  
Alessandra C. Pinheiro ◽  
...  

Abstract The crystal structures of four azines, namely 1-3-bis(4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 1, 1,3-bis(2,3-dimethoxyphenyl)-2,3-diaza-1,4-butadiene, 2, 1,3-bis(2-hydroxy-3-methoxyphenyl)-2,3-diaza-1,4-butadiene, 3, and 1,3-bis(2-hydroxy-4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 4, are reported. Molecules of 3 and 4, and both independent molecules of 2, Mol A and Mol B, possess inversion centers. The central C=N–N=C units in each molecule is planar with an (E,E) conformation. The intermolecular interactions found in the four compounds are C–H···O, C–H–N, C–H---π and π---π interactions. However, there is no consistent set of intermolecular interactions for the four compounds. Compound, 1, has a two-dimensional undulating sheet structure, generated from C–H···O and C–H···N intermolecular hydrogen bonds. The only recognized intermolecular interaction in 2 is a C–H···O hydrogen bond, which results in a zig-zag chain of alternating molecules, Mol A and Mol B. While 3 forms a puckered sheet of molecules, solely via C–H···π interactions, its isomeric compound, 4, has a more elaborate three-dimensional structure generated from a combination of C–H···O hydrogen bonds, C–H···π and π···π interactions. The findings in this study, based on both PLATON and Hirshfeld approaches, for the four representative compounds match well the reported structural findings in the literature of related compounds, which are based solely on geometric parameters.


Author(s):  
Rafika Bouchene ◽  
Zohir Lecheheb ◽  
Ratiba Belhouas ◽  
Sofiane Bouacida

Two new organic–inorganic hybrid compounds, triethylenetetraammonium hexachloridostannate (IV) dichloride dihydrate, (C6H22N4)[SnCl6]Cl2·2H2O, (I), and 1,4-bis(2-ammonioethyl)piperazin-1,4-diium hexachloridostannate (IV) dichloride dihydrate, (C8H24N4)[SnCl6]Cl2·2H2O, (II), have been synthesized from the same starting materials. In each case both the cations and anions are located about inversion centers. Their crystal structures exhibits alternating inorganic and organic stacking sheets in (I) and layers in (II), with Cl− ions and water molecules occupying the space in between. The cohesion of the three-dimensional frameworks are governed by N—H...Cl, N—H...O, C—H...Cl and O—H...Cl hydrogen bonds. Hirshfeld surface analysis of both crystal structures indicates that the H...Cl/Cl...H contacts exert an important influence on the stabilization of the packing.


2016 ◽  
Vol 72 (11) ◽  
pp. 882-889 ◽  
Author(s):  
Tamara J. Bednarchuk ◽  
Vasyl Kinzhybalo ◽  
Adam Pietraszko

Hybrid materials, fabricated by the combination of inorganic and organic components, have potential applications in chemistry and are endowed with the advantages of both building elements. There are several types of intermolecular interactions present in these hybrid compounds, including electrostatic forces, π–π stacking and hydrogen-bonding interactions, the latter playing an important role in the construction of three-dimensional architectures and stabilizing supramolecular crystal structures. Analysis of the intermolecular interactions and their influence on packing modes therefore requires focused scientific attention. Four new organic–inorganic salts, namely 2-amino-4-methyl-3-nitropyridinium hydrogen sulfate, C6H8N3O2+·HSO4−, bis(2-amino-4-methyl-3-nitropyridinium) sulfate, 2C6H8N3O2+·SO42−, 2-amino-3-methylpyridinium hydrogen sulfate, C6H9N2+·HSO4−, and bis(2-amino-3-methylpyridinium) sulfate monohydrate, 2C6H9N2+·SO42−·H2O, have been synthesized and characterized by X-ray diffraction. The crystal structures are stabilized by intra- and intermolecular hydrogen bonds, as well as by weak π–π stacking and lp–π (lp is lone pair) interactions. Hirshfeld surface analysis was employed in order to study intermolecular interactions.


2014 ◽  
Vol 69 (9-10) ◽  
pp. 950-964 ◽  
Author(s):  
Gerhard Laus ◽  
Volker Kahlenberg ◽  
Klaus Wurst ◽  
Herwig Schottenberger

AbstractIntroduction of sulfur into the 5-position of 1,4-disubstituted quaternary 1,2,4-triazolium salts (1-9; Cl, Br, I, BF4, PF6, CH3OSO3 were used as anions) by two methods was investigated. The syntheses of nine 1,4-disubstituted 1,2,4-triazoline-5-thiones 10-18 are reported (1, 10: R1 = CH3, R2 = CH3; 2, 11: R1 = NH2, R2 = CH3; 3, 12: R1 = NH2, R2 = CH(CH3)2; 4, 13: R1 = N(CH3)2, R2 = CH3; 5, 14: R1 = N(CH3)2, R2 = CH(CH3)2; 6, 15: R1 = CH3, R2 = NH2; 7, 16: R1 = OCH2Ph, R2 = CH3; 8, 17: R1 = OCH2Ph, R2 = CH2CH3; 9, 18: R1 = CH3, R2 = CH2Ph). Compounds 11-17 represent 1-amino, 4-amino, 4-dimethylamino, and 4-benzyloxy-1,2,4-triazoline-5- thiones, whereas 10 served as a reference compound. Thione 18 was identified as an unexpected by-product in the synthesis of 16 and was also prepared independently. Thermolysis of 10 in air gave 1,4-dimethyl-1,2,4-triazolium hydrogensulfate. Crystal structures of eight 1,4-disubstituted 1,2,4- triazoline-5-thiones were determined by single-crystal X-ray diffraction. Intermolecular hydrogen bonds (C-H···S, C-H···N, N-H···N, N-H···S) were observed in the solid state. The solvent-dependent 1H NMR chemical shifts of signals of 10 and 13 were satisfactorily correlated with the Kamlet- Abboud-Taft π* and b parameters in ten solvents. From the lack of correlation with the a parameter and from the C=S bond length (average 1.67 Å) a significant contribution of a mesoionic imidazolium-2-thiolate resonance structure seems unlikely


Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3099 ◽  
Author(s):  
Michał Gacki ◽  
Karolina Kafarska ◽  
Anna Pietrzak ◽  
Izabela Korona-Głowniak ◽  
Wojciech M. Wolf

Three metal complexes of mefenamato ligand 1 were synthesized: [Co2(mef)4(EtOH)2(H2O)4]: 2; [Co(mef)2(MeOH)4]∙2MeOH: 3; and [Ni(mef)2(MeOH)4]∙2MeOH: 4. Their compositions and properties were investigated by elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Crystal structures were determined by the single crystal X-ray diffraction technique. Additionally, their antioxidant and antimicrobial activity were established, thus proving good/moderate bioactivity against Gram-positive bacteria and yeasts. In the crystal structure of 2, an apical water molecule is shared between two adjacent cobalt(II) ions, resulting in the formation of a polymeric chain extending along the [100] direction. Meanwhile, structures 3 and 4 have strong intermolecular hydrogen bonds with diverse topologies that yield unique quasi-isostructural arrangements. The packing topology is reflected by the Hirshfeld surface analysis of intermolecular contacts.


2002 ◽  
Vol 57 (10) ◽  
pp. 1090-1100
Author(s):  
Franziska Emmerling ◽  
Caroline Röhr

AbstractThe title compounds were synthesized at a temperature of 700 °C via oxidation of elemental Bi with the hyperoxides AO2 or via reaction of the elemental alkali metals A with Bi2O3. Their crystal structures have been determined by single crystal x-ray diffraction. They are dominated by two possible surroundings of Bi by O, the ψ-trigonal-bipyramidal three (B) and the ψ-tetrahedral four (T) coordination. Cs6Bi4O9 (triclinic, spacegroup P1̄, a = 813.82(12), b = 991.60(14), c = 1213.83(18) pm, α = 103.658(2), β = 93.694(3), γ = 91.662(3)°, Z = 2) contains centrosymmetric chain segmentes [Bi8O18]12- with six three- (T) and two four-coordinated (B) Bi(III) centers. K9Bi5O13 (monoclinic, spacegroup P21/c, a = 1510.98(14), b = 567.59(5), c = 2685.6(2) pm, β = 111.190(2)°, Z = 4) is a mixed valence compound with isolated [BivO4]3- tetrahedra and chains [BiIII4O9]6- of two T and two B coordinated Bi. In the compounds A2Bi4O7 (A = Rb/Cs: monoclinic, C2/c, a = 2037.0(3) / 2130.6(12), b = 1285.5(2) / 1301.9(7), c = 1566.6(2) / 1605.6(9) pm, β = 94.783(3) / 95.725(9)°, Z = 8) ribbons [Bi4O6O2/2]2- are formed, which are condensed to form a three-dimensional framework.


1966 ◽  
Vol 44 (8) ◽  
pp. 939-943 ◽  
Author(s):  
A. K. Das ◽  
I. D. Brown

(NH4)2TeBr6 and Cs2TeBr6 crystals have the cubic K2PtCl6 structure with space group: [Formula: see text] with a0 = 10.728 ± 0.003 Å and 10.918 ± 0.002 Å respectively. The positional coordinate of the bromine atom, and the anisotropic temperature factors of all atoms in the unit cell, have been refined for both crystals by a full matrix least-squares analysis of the three dimensional X-ray diffraction data (R = 0.08). The Te—Br distance, corrected for probable thermal motions of atoms forming the bond, is 2.70 ± 0.01 Å in both crystals.


Author(s):  
Amani Direm ◽  
Angela Altomare ◽  
Anna Moliterni ◽  
Nourredine Benali-Cherif

Three new proton transfer compounds, [2-ammonio-5-methylcarboxybenzene perchlorate (1), (C8H10NO2+·ClO4−), 4-(ammoniomethyl)carboxybenzene nitrate (2), (C8H10NO2+·NO3−), and 4-(ammoniomethyl)carboxybenzene perchlorate (3), (C8H10NO2+·ClO4−)], have been synthesized, their IR modes of vibrations have been assigned and their crystal structures studied by means of single-crystal X-ray diffraction. Their asymmetric units consist of one cation and one anion for both compounds (1) and (2). However, the crystal structure of compound (3) is based on a pair of cations and a pair of anions in its asymmetric unit. The three-dimensional Hirshfeld surface analysis and the two-dimensional fingerprint maps revealed that the three structures are dominated by H...O/O...H and H...H contacts. The strongest hydrogen-bonding interactions are associated with O—H...O and N—H...O constituting the highest fraction of approximately 50%, followed by those of the H...H type contributing 20%. Other close contacts are also present, including weak C...H/H...C contacts (with about 10%).


2016 ◽  
Vol 20 (07) ◽  
pp. 833-842
Author(s):  
Rahul Soman ◽  
Subramaniam Sujatha ◽  
Chellaiah Arunkumar

Synthesis and crystal structure analysis of meso-tetratolylporphyrins, 1–5 combined with computational Hirshfeld surface analysis were investigated. The crystal packing of porphyrins 1, 3 and 4 are arranged in an “orthogonal fashion” whereas 2 and 5 are in a “slip-stack or off-set fashion” through various intermolecular interactions. Compound 2 exhibits saddle geometry whereas 5 showed a domed geometry as evident from the single crystal X-ray diffraction studies. The enhancement of non-planarity in 2 is probably due to the presence of numerous intermolecular interactions caused by the presence of trifluoroacetate anions on both faces of the porphyrin in addition to the bulky bromine groups at the [Formula: see text]-pyrrole positions. In 5, the non-planarity is merely due to the metal coordination at the porphyrin core as pentacoordinated Mn[Formula: see text] center with a chloro ligand in the axial position. Hirshfeld surface analysis was performed in order to analyze the various intermolecular interactions present in these porphyrins and the result was discussed.


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