scholarly journals Crystal structures of two 2,3-diethylnaphtho[2,3-g]quinoxaline-6,11-dione derivatives

2017 ◽  
Vol 73 (8) ◽  
pp. 1125-1129
Author(s):  
Craig M. Forsyth ◽  
Craig L. Francis

Two new 5,12-disubstituted 2,3-diethylnaphtho[2,3-g]quinoxaline-6,11-dione compounds were readily synthesized from the commercial dye quinizarin. For 2,3-diethyl-5,12-dihydroxynaphtho[2,3-g]quinoxaline-6,11-dione, (II), C20H16N2O4, the molecule displays a near planar conformation and both hydroxy groups participate in intramolecular O—H...O(carbonyl) hydrogen bonds. In the crystal, π–π ring interactions [minimum ring centroid separation = 3.5493 (9) Å] form stacks of co-planar molecules down the c axis, while only minor intermolecular C—H...O interactions are present. In contrast, in 2,3-diethyl-5,12-bis(piperidin-1-yl)naphtho[2,3-g]quinoxaline-6,11-dione, (IV), C30H34N4O2, which contains two independent, but similar, molecules in the asymmetric unit, the polycyclic cores have a significant twist, with dihedral angles of 29.79 (6) and 29.31 (7)° between the terminal rings and only minor intermolecular C—H...O hydrogen-bonding interactions are present. Electron density associated with additional solvent molecules disordered about a fourfold axis was accounted for using the SQUEEZE procedure in PLATON [Spek (2015). Acta Cryst. C71, 9–18].

2014 ◽  
Vol 70 (7) ◽  
pp. m272-m273
Author(s):  
Saravanan Gowrisankar ◽  
Helfried Neumann ◽  
Anke Spannenberg ◽  
Matthias Beller

The title compound, [Ru(CO3)(η6-C6H6){(C6H11)2P(CH2C10H7)}]·3CHCl3, was synthesized by carbonation of [RuCl2(η6-C6H6){(C6H11)2P(CH2C10H7)}] with NaHCO3in methanol at room temperature. The RuIIatom is surrounded by a benzene ligand, a chelating carbonate group and a phosphane ligand in a piano-stool configuration. The crystal packing is consolidated by C—H...O and C—H...Cl hydrogen-bonding interactions between adjacent metal complexes and between the complexes and the solvent molecules. The asymmetric unit contains one metal complex and three chloroform solvent molecules of which only one was modelled. The estimated diffraction contributions of the other two strongly disordered chloroform solvent molecules were substracted from the observed diffraction data using the SQUEEZE procedure inPLATON[Spek (2009).Acta Cryst.D65, 148–155].


Author(s):  
Muhabbat Honkeldieva ◽  
Samat Talipov ◽  
Rustam Mardanov ◽  
Bakhtiyar Ibragimov

The title compound, C34H38O8(systematic name: 5,5′-diisopropyl-2,2′,3,3′-tetramethoxy-7,7′-dimethyl-2H,2′H-8,8′-bi[naphtho[1,8-bc]furan]-4,4′-diol), has been obtained from a gossypol solution in a mixture of dimethyl sulfate and methanol. The molecule is situated on a twofold rotation axis, so the asymmetric unit contains one half-molecule. In the molecule, the hydroxy groups are involved in intramolecular O—H...O hydrogen bonds, and the two naphthyl fragments are inclined each to other by 83.8 (1)°. In the crystal, weak C—H...O and C—H...π interactions consolidate the packing, which exhibits channels with an approximate diameter of 6 Å extending along thec-axis direction. These channels are filled with highly disordered solvent molecules, so their estimated scattering contribution was subtracted from the observed diffraction data using the SQUEEZE option inPLATON[Spek, A. L. (2015).Acta Cryst. C71, 9–18].


2014 ◽  
Vol 70 (8) ◽  
pp. 58-61
Author(s):  
Aina Mardia Akhmad Aznan ◽  
Zanariah Abdullah ◽  
Vannajan Sanghiran Lee ◽  
Edward R. T. Tiekink

The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, withZ′ = 4) of the previously reported monoclinic (P21/c, withZ′ = 2) form [Akhmad Aznanet al.(2010).Acta Cryst.E66, o2400]. Four independent molecules comprise the asymmetric unit, which have the common features of asyndisposition of the pyridine N atom and the toluene ring, and an intramolecular amine–nitro N—H...O hydrogen bond. The differences between molecules relate to the dihedral angles between the rings which range from 2.92 (19) to 26.24 (19)°. The geometry-optimized structure [B3LYP level of theory and 6–311 g+(d,p) basis set] has the same features except that the entire molecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C—H...O, C—H...π, nitro-N—O...π and π–π interactions [inter-centroid distances = 3.649 (2)–3.916 (2) Å].


2016 ◽  
Vol 72 (10) ◽  
pp. 1503-1508
Author(s):  
Miguel Ángel Claudio-Catalán ◽  
Felipe Medrano ◽  
Hugo Tlahuext ◽  
Carolina Godoy-Alcántar

The asymmetric unit of the title compound, C56H50N6O8S2·3C6H4Cl2, contains two half-molecules of the parent,AandB, which both have crystallographic inversion symmetry, together with three 2,3-dichlorobenzene molecules of solvation. MoleculesAandBare conformationally similar, with dihedral angles between the central naphthalenediimide ring and the peripheral naphthalene and benzyl rings of 2.43 (7), 81.87 (7)° (A) and 3.95 (7), 84.88 (7)° (B), respectively. The conformations are stabilized by the presence of intramolecular π–π interactions between the naphthalene ring and the six-membered diimide ring of the central naphthalenediimide moiety, with ring centroid-to-centroid distances of 3.5795 (8) Å (A) and 3.5640 (8) Å (B). In the crystal, C—H...O hydrogen bonds link the molecules into infinite supramolecular chains along thecaxis. These chains are interconnected through C—H...π and offset π–π interactions, generating supramolecular nanotubes which are filled by 1,2-dichlorobenzene molecules.


2012 ◽  
Vol 68 (8) ◽  
pp. o2357-o2357 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
Gabriel Guerrero-Luna ◽  
Anselmo A. Martínez-Gallegos

Diosgenin [or (22R,25R)-spirost-5-en-3β-ol] is the starting material of the Marker degradation, a cheap semi-synthesis of progesterone, which has been designated as an International Historic Chemical Landmark. Thus far, a single X-ray structure for diosgenin is known, namely its dimethyl sulfoxide solvate [Zhanget al.(2005).Acta Cryst.E61, o2324–o2325]. We have now determined the structure of the hemihydrate, C27H42O3·0.5H2O. The asymmetric unit contains two diosgenin molecules, with quite similar conformations, and one water molecule. Hydroxy groups in steroids and water molecules form O—H...O hydrogen-bondedR54(10) ring motifs. Fused edge-sharingR(10) rings form a backbone oriented along [100], which aggregates the diosgenin molecules in the crystal structure.


2014 ◽  
Vol 70 (3) ◽  
pp. o279-o280
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
R. Ranjith Kumar ◽  
V. Jeyachandran ◽  
P. L. Nilantha Lakshman

The asymmetric unit of the title compound, C19H16N2O5S, contains four independent molecules (A,B,CandD), with two molecules (BandD) displaying disorder in their methylsulfanyl groups [occupancy ratios of 0.797 (11):0.203 (11) and 0.85 (2):0.15 (2)]. The nitro groups are twisted slightly out of the planes of the 2-pyrroline rings to which they are bonded with dihedral angles of 10.17 (1), 8.01 (1), 9.44 (1) and 8.87 (1)° in moleculesA,B,CandD, respectively. The 2-pyrroline rings are almost orthogonal to the attached tolyl rings, forming dihedral angles of 73.44 (1), 81.21 (1), 88.18 (8) and 73.94 (1)° for moleculesA,B,CandD, respectively. A weak intramolecular O—H...O interaction is observed in moleculesBandC. The two hydroxy groups in each molecule are involved in intermolecular O—H...O hydrogen bonding. In the crystal, molecules are connectedviaO—H...O and C—H...O hydrogen bonds, forming a complex three-dimensional network.


2015 ◽  
Vol 71 (12) ◽  
pp. o953-o954
Author(s):  
Badma N. Mankaev ◽  
Kirill V. Zaitsev ◽  
Sergey S. Karlov ◽  
Mikhail P. Egorov ◽  
Andrei V. Churakov

The asymmetric unit in the structure of the title compound, C25H22NO2+·Br−·0.5CH2Cl2·0.5H2O, comprises two pseudosymmetry-related cations, two bromide anions, a dichloromethane molecule and a water molecule of solvation. The two independent cations are conformationally similar with the comparative dihedral angles between the central pyridine ring and the three benzene substituent rings being 3.0 (2), 36.4 (1) and 24.2 (1)°, and 3.7 (2), 36.5 (1) and 24.8 (1)°, respectively. In the crystal, the cations, anions and water molecules are linked through O—H...O and O—H...Br hydrogen bonds, forming an insular unit. Within the cations there are also intramolecular N—H...O hydrogen bonds. Adjacent centrosymmetrically related aggregates are linked by π–π stacking interactions between the pyridine ring and a benzene ring in both cations [ring-centroid separations = 3.525 (3) and 3.668 (3) Å], forming chains extending across theacdiagonal. Voids between these chains are filled by dichloromethane molecules.


2014 ◽  
Vol 70 (9) ◽  
pp. o971-o972
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
S. Sivakumar ◽  
R. Ranjith Kumar ◽  
P. L. Nilantha Lakshman

The asymmetric unit of the title compound, C21H15Cl2N5O4, contains two independent molecules (AandB) having similar conformations. The amine (NH2) group forms an intramolecular hydrogen bond with the benzoyl group, giving anS(6) ring motif in both molecules. The central six-membered rings adopt sofa conformations and the imidazole rings are planar (r.m.s deviations = 0.0150 and 0.0166 Å). The pyridine and imidazole rings are inclined to one another by 3.54 (1) and 3.03 (1)° in moleculesAandB, respectively. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains along theaaxis which encloseR22(16) ring motifs. The rings are linked by weak N—H...O and C—H...O hydrogen bonds and C—H...π interactions forming sheets lying parallel to (001). A region of disordered electron density, most probably disordered solvent molecules, occupying voids ofca753 Å3for an electron count of 260, was treated using the SQUEEZE routine inPLATON[Spek (2009).Acta Cryst.D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement.


2016 ◽  
Vol 72 (10) ◽  
pp. 738-742 ◽  
Author(s):  
Daniel E. Lynch ◽  
Graham Smith ◽  
Tony D. Keene ◽  
Peter N. Horton

The study of ternary systems is interesting because it introduces the concept of molecular preference/competition into the system where one molecule may be displaced because the association between the other two is significantly stronger. Current definitions of a tertiary system indicate that solvent molecules are excluded from the molecule count of the system and some of the latest definitions state that any molecule that is not a solid in the parent form at room temperature should also be excluded from the molecule count. In the structure of the quinoline adduct hydrate of tryptaminium 3,5-dinitrobenzoate, 3C10H13N2+·3C7H3N2O6−·2C9H7N·2H2O, the asymmetric unit comprises multiple cation and anion species which are conformationally similar among each type set. In the crystal, a one-dimensional hydrogen-bonded supramolecular structure is generated through extensive intra- and inter-unit aminium N—H...O and N—H...N, and water O—H...O hydrogen bonds. Within the central-core hydrogen-bonding associations, conjoined cyclicR44(10),R53(10) andR44(12) motifs are generated. The unit is expanded into a one-dimensional column-like polymer extending along [010]. Present also in the crystal packing of the structure are a total of 19 π–π interactions involving both cation, anion and quinoline species [ring-centroid separation range = 3.395 (3)–3.797 (3) Å], as well as a number of weak C—H...O hydrogen-bonding associations. The presence of the two water molecules in the crystal structure is considered to be the principal causative factor in the low symmetry of the asymmetric unit.


IUCrData ◽  
2021 ◽  
Vol 6 (5) ◽  
Author(s):  
Yingying Fan ◽  
Jianfeng Li

In the title compound, [FeII(C68H44N12O4)(C4H6N2)2]·C4H6N2·1.5C4H8O, the central FeII ion is coordinated by four pyrrole N atoms of the porphyrin core and two N atoms of the 1-methylimidazole ligands in the axial sites. One 1-methylimidazole and one and a half tetrahydrofuran solvent molecules are also present in the asymmetric unit. The complex exhibits a near planar porphyrin core conformation, in which the iron centre is slightly displaced towards the hindered porphyrin side (0.01 Å). The average Fe—Np (Np refers to the pyrrole nitrogen atoms in the porphyrin) bond length is 1.990 (9) Å, and the axial Fe—NIm (NIm refers to the imidazole nitrogen atoms) bond lengths are 1.993 (3) and 2.004 (3) Å. The dihedral angle between the two coordinated 1-methylimidazole planes is 56.6 (2)°. The dihedral angles between the 1-methylimidazole planes and the planes of the closest Fe—Np vector are 16.8 (2) and 39.8 (2)°. N—H...N and N—H...O interactions are observed in the crystal structure.


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