Bis(2-nitrophenyl) selenide, bis(2-aminophenyl) selenide and bis(2-aminophenyl) telluride: structural and theoretical analysis

Author(s):  
Raju Saravanan ◽  
Harkesh B. Singh ◽  
Ray J. Butcher

Three organoselenium and organotellurium compounds containing ortho substitutents, namely, bis(2-nitrophenyl) selenide, C12H8N2O4Se, 2, bis(2-aminophenyl) selenide, C12H12N2Se, 3, and bis(2-aminophenyl) telluride, C12H12N2Te, 7, have been investigated by both structural and theoretical methods. In the structures of all three compounds, there are intramolecular contacts between both Se and Te with the ortho substituents. In the case of 2, this is achieved by rotation of the nitro group from the arene plane. For 3, both amino groups exhibit pyramidal geometry and are involved in intramolecular N—H...Se interactions, with one also participating in intermolecular N—H...N hydrogen bonding. While 3 and 7 are structurally similar, there are some significant differences. In addition to both intramolecular N—H...Te interactions and intermolecular N—H...N hydrogen bonding, 7 also exhibits intramolecular N—H...N hydrogen bonding. In the packing of these molecules, for 2, there are weak intermolecular C—H...O contacts and these, along with the O...N interactions mentioned above, link the molecules into a three-dimensional array. For 3, in addition to the N—H...N and N—H...Se interactions, there are also weak intermolecular C—H...Se interactions, which also link the molecules into a three-dimensional array. On the other hand, 7 shows intermolecular N—H...N interactions linking the molecules into R 2 2(16) centrosymmetric dimers. In the theoretical studies, for compound 2, AIM (atoms in molecules) analysis revealed critical points in the Se...O interactions with values of 0.017 and 0.026 a.u. These values are suggestive of weak interactions present between Se and O atoms. For 3 and 7, the molecular structures displayed intramolecular, as well as intermolecular, hydrogen-bond interactions of the N—H...N type. The strength of this hydrogen-bond interaction was calculated by AIM analysis. Here, the intermolecular (N—H...N) hydrogen bond is stronger than the intramolecular hydrogen bond. This was confirmed by the electron densities for 3 and 7 [ρ(r) = 0.015 and 0.011, respectively].

Author(s):  
Rosita Diana ◽  
Angela Tuzi ◽  
Barbara Panunzi ◽  
Antonio Carella ◽  
Ugo Caruso

The title benzofuran derivatives 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF1), C19H18N2O6, and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF2), C18H16N2O7, recently attracted attention because of their promising antitumoral activity. BF1 crystallizes in the space group P\overline{1}. BF2 in the space group P21/c. The nitrophenyl group is inclined to benzofuran moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the molecular structures of BF1 and BF2 is the intramolecular N—H...Ocarbonyl hydrogen bond. In the crystal of BF1, the molecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of molecules along the b-axis direction are linked by O—H...Omethoxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).


Author(s):  
Graham Smith ◽  
Urs D. Wermuth

In the structure of the brucinium salt of 4-aminophenylarsonic acid (p-arsanilic acid), systematically 2,3-dimethoxy-10-oxostrychnidinium 4-aminophenylarsonate tetrahydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water molecules of solvation are accommodated between the layers and are linked to them through a primary cation N—H...O(anion) hydrogen bond, as well as through water O—H...O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.


2000 ◽  
Vol 55 (8) ◽  
pp. 738-752 ◽  
Author(s):  
Oliver Moers ◽  
Karna Wijaya ◽  
Ilona Lange ◽  
Armand Blaschette ◽  
Peter G. Jones

As an exercise in crystal engineering, low-temperature X-ray structures were determined for six rationally designed ionic solids of general formula BH+(MeSO2)2N−, where BH+ is 2-aminopyridinium (2, monoclinic, space group P21/c, Z = 4), 2-aminopyrimidinium (3, orthorhombic, Pbca, Z = 8), 2-aminothiazolium (4, orthorhombic, Pbcn, Z = 8), 2-amino-6-methylpyridinium (5, solvated with 0.5 H20, monoclinic, C2/c, Z = 8), 2-amino-1,3,4-thiadiazolium (6, triclinic, P1̄, Z = 2), or 2-amino-4,6-dimethylpyrimidinium (7, orthorhombic. Fdd2, Z = 16). The onium cations in question exhibit a trifunctional hydrogen-bond donor sequence H − N (H*)-C (sp2) − N − H , which is complementary to an O − S (sp3)−N fragment of the anion and simultaneously expected to form a third hydrogen bond via the exocyclic N − H* donor. Consequently, all the crystal packings contain cation-anion pairs assembled by an N − H ∙∙∙ N and an N −H ∙∙∙ O hydrogen bond, these substructures being mutually associated through an N − H* ∙∙∙ O bond. For the robust eight-membered ring synthon within the ion pairs [graph set N2 = R22(8), antidromic], two supramolecular isomers were observed: In 2 and 3, N − H ∙∙∙ N originates from the ring NH donor and N − H ∙∙∙ O from the exocyclic amino group, whereas in 4-7 these connectivities are reversed. The third hydrogen bond, N − H*∙∙∙ O , leads either to chains of ion pairs (generated by a 21 transformation in 2-4 or by a glide plane in 5) or to cyclic dimers of ion pairs (Ci symmetric in 6, C2-symmetric in 7). The overall variety of motifs observed in a small number of structures reflects the limits imposed on the prediction of hydrogen bonding patterns. Owing to the excess of potential acceptors over traditional hydrogen-bond donors, several of the structures display prominent non-classical secondary bonding. Thus, the cyclodimeric units of 6 are associated into strands through short antiparallel O ∙∙∙ S(cation) interactions. In the hemihydrate 5, two independent C-H(cation) ∙∙∙ O bonds generate a second antidromic R22(8) pattern, leading to sheets composed of N − H ∙∙∙ N/O connected catemers; the water molecules are alternately sandwiched between and O - H ∙∙∙ O bonded to the sheets to form bilayers, which are cross-linked by a third C − H (cation ) ∙∙∙ O contact. The roof-shaped cyclodimers occurring in 7 occupy the polar C2 axes parallel to z and build up hollow Car− H ∙∙∙ O bonded tetrahedral lattices; in order to fill their large empty cavities, five translationally equivalent lattices mutually interpenetrate.


1996 ◽  
Vol 52 (3) ◽  
pp. 487-499 ◽  
Author(s):  
M. Kubicki ◽  
T. W. Kindopp ◽  
M. V. Capparelli ◽  
P. W. Codding

The crystal structures of five 1,4-dihydro-2,3-quinoxalinediones, antagonists of the NMDA modulatory glycine binding site on the excitary amino acid (EAA) receptor complex, have been determined: (I) 6,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (DNQX); (II) 5,7-dinitro-1,4-dihydro-2,3-quinoxalinedione (MNQX); (III) 6-nitro-1,4-dihydro-2,3-quinoxalinedione hydrate; (IV) 6,7-dichloro-1,4-dihydro-2,3-quinoxalinedione; (V) 5,7-dichloro-1,4-dihydro-2,3-quinoxalinedione dimethylformamide. The crystal structure of the most active compound (II) contains a unique intramolecular N—H...O(NO2) hydrogen bond, which may be important for activity, as semiempirical calculations show that this bond is stable over a wide range of dihedral angles between the planes of the molecule and of the nitro group. In the other compounds the intermolecular hydrogen bonds connect molecules into three-dimensional networks. In compounds (I), (III) and (IV) head-to-tail: π-stacking is found between molecules connected by a center of symmetry. The geometries of the hydrogen-bonded —NH—C=O fragments show evidence of π-cooperativity or resonance-assisted hydrogen bonding. Graph-set analysis of the hydrogen-bond patterns of quinoxalinedione derivatives shows a tendency to form two types of hydrogen-bonding motifs: a centrosymmetric dimeric ring and an infinite chain. Even though this pattern may be modified by the presence of additional hydrogen-bond acceptors and/or donors, as well as by solvent molecules, general similarities have been found. Comparison of all quinoxalinedione structures suggests that the hydrogen-bonding pattern necessary for the biological activity at the glycine binding site contains one donor and two acceptors.


2006 ◽  
Vol 62 (4) ◽  
pp. m875-m877
Author(s):  
Wei-Bing Zhang ◽  
Shuang-Di Ruan ◽  
Shu-Juan Zhu ◽  
Hong-Ping Xiao ◽  
Sai-Ya Ye

In the title compound, [Cu2(C7H4O5S)2(C12H8N2)2(H2O)2]·3H2O, each copper(II) atom is coordinated by two N atoms from one 1,10-phenanthroline molecule, two carboxylate O atoms from two 2-sulfonatobenzoato dianions and one aqua O atom in a distorted square pyramidal geometry. The 2-sulfonatobenzoato dianions function as μ2-bridging ligands in the formation of a dinuclear complex. Intermolecular hydrogen-bond interactions link the dinuclear units into a two-dimensional network structure.


1988 ◽  
Vol 66 (9) ◽  
pp. 2166-2171 ◽  
Author(s):  
K. Kulińska ◽  
M. Wiewiórowski

The homo and heteroassociation patterns of lupinine and epilupinine in different solvents and at various concentrations have been studied. In n-hexane, n-heptane, CCl4, and C2H4Cl2 solvents, lupinine monomers with an intramolecular OH … N hydrogen bond dominate over homoassociates with an OH … O′ intermolecular hydrogen bond even in concentrated solutions. Homoassociation of lupinine by intermolecular OH … N′ hydrogen bonding is observed only in saturated solutions. In chloroform solution any intermolecular homoassociation is effectively blocked because of significant affinity of chloroform molecules acting as a weak acid toward the free electron pairs of the oxygen atom from the hydroxyl group that would be otherwise engaged in intramolecular OH … N hydrogen bonding. Epilupinine in n-hexane, n-heptane, CCl4, C2H4Cl2, and chloroform solutions forms possible homoassociates both by OH … N′ and OH … O′ intermolecular hydrogen bonding. In dioxane-d8, DMSO, and D2O solvents both lupinine and epilupinine form heteroassociates with solvent molecules.


2018 ◽  
Vol 74 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte

Doubly and triply hydrogen-bonded supramolecular synthons are of particular interest for the rational design of crystal and cocrystal structures in crystal engineering since they show a high robustness due to their high stability and good reliability. The compound 5-methyl-2-thiouracil (2-thiothymine) contains an ADA hydrogen-bonding site (A = acceptor and D = donor) if the S atom is considered as an acceptor. We report herein the results of cocrystallization experiments with the coformers 2,4-diaminopyrimidine, 2,4-diamino-6-phenyl-1,3,5-triazine, 6-amino-3H-isocytosine and melamine, which contain complementary DAD hydrogen-bonding sites and, therefore, should be capable of forming a mixed ADA–DAD N—H...S/N—H...N/N—H...O synthon (denoted synthon 3s N·S;N·N;N·O), consisting of three different hydrogen bonds with 5-methyl-2-thiouracil. The experiments yielded one cocrystal and five solvated cocrystals, namely 5-methyl-2-thiouracil–2,4-diaminopyrimidine (1/2), C5H6N2OS·2C4H6N4, (I), 5-methyl-2-thiouracil–2,4-diaminopyrimidine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C4H6N4·C3H7NO, (II), 5-methyl-2-thiouracil–2,4-diamino-6-phenyl-1,3,5-triazine–N,N-dimethylformamide (2/2/1), 2C5H6N2OS·2C9H9N5·C3H7NO, (III), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylformamide (2/2/1), (IV), 2C5H6N2OS·2C4H6N4O·C3H7NO, (IV), 5-methyl-2-thiouracil–6-amino-3H-isocytosine–N,N-dimethylacetamide (2/2/1), 2C5H6N2OS·2C4H6N4O·C4H9NO, (V), and 5-methyl-2-thiouracil–melamine (3/2), 3C5H6N2OS·2C3H6N6, (VI). Synthon 3s N·S;N·N;N·O was formed in three structures in which two-dimensional hydrogen-bonded networks are observed, while doubly hydrogen-bonded interactions were formed instead in the remaining three cocrystals whereby three-dimensional networks are preferred. As desired, the S atoms are involved in hydrogen-bonding interactions in all six structures, thus illustrating the ability of sulfur to act as a hydrogen-bond acceptor and, therefore, its value for application in crystal engineering.


2004 ◽  
Vol 82 (5) ◽  
pp. 616-621 ◽  
Author(s):  
Xian-Ming Zhang ◽  
Chan-Juan Bai ◽  
Yan-Li Zhang ◽  
Hai-Shun Wu

A novel organic-templated zincophosphate, namely (C6H16N2)[Zn(HPO4)2], was hydrothermally synthesized and X-ray single-crystal structural analysis reveals that the anions [Zn(HPO4)2]2–, which have square-twisted chains containing corner-sharing four-rings of alternating ZnO4 and PO4 tetrahedra, are assemblied via self-complementary strong and symmetrical hydrogen-bonding R22(8) synthons between the phosphate groups into three-dimensional hydrogen bond frameworks featuring three-dimensional intersecting pseudochannels. The doubly protonated 2,5-dimethylpiperazinium cations are attached to the three-dimensional inorganic framework via N-H···O hydrogen bonds to strengthen the 3-D network.


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