scholarly journals Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

2018 ◽  
Vol 74 (12) ◽  
pp. 1735-1740 ◽  
Author(s):  
James L. Wardell ◽  
Edward R. T. Tiekink

The crystal and molecular structures of the title molecular salts, C4H12NO+·C7H5N2O4 −, (I), C6H16NO+·C7H5N2O4 −, (II), and C4H12NO3 +·C7H5N2O4 −, (III), are described. The common feature of these salts is the presence of the 2-amino-4-nitrobenzoate anion, which exhibit non-chemically significant variations in the conformational relationships between the carboxylate and nitro groups, and between these and the benzene rings they are connected to. The number of ammonium-N—H H atoms in the cations increases from one to three in (I) to (III), respectively, and this variation significantly influences the supramolecular aggregation patterns in the respective crystals. Thus, a linear supramolecular chain along [100] sustained by charge-assisted tertiary-ammonium-N—H...O(carboxylate), hydroxy-O—H...O(carboxylate) and amino-N—H...O(carboxylate) hydrogen-bonds is apparent in the crystal of (I). Chains are connected into a three-dimensional architecture by methyl-C—H...O(hydroxy) and π–π interactions, the latter between benzene rings [inter-centroid separation = 3.5796 (10) Å]. In the crystal of (II), a supramolecular tube propagating along [901] arises as a result of charge-assisted secondary-ammonium-N—H...O(carboxylate) and hydroxy-O—H...O(carboxylate) hydrogen-bonding. These are connected by methylene- and methyl-C—H...O(nitro) and π–π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å]. Finally, double-layers parallel to (100) sustained by charge-assisted ammonium-N—H...O(carboxylate), ammonium-N—H...O(hydroxy) and hydroxy-O—H...O(carboxylate) hydrogen-bonds are apparent in the crystal of (III). These are connected in a three-dimensional architecture by amine-N—H...O(nitro) hydrogen-bonds.

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

The crystal and molecular structures of the title 1:2 co-crystal, C14H14N4O2·2C7H6O2, are described. The oxalamide molecule has a (+)-antiperiplanar conformation with the 4-pyridyl residues lying to either side of the central, almost planar C2N2O2 chromophore (r.m.s. deviation = 0.0555 Å). The benzoic acid molecules have equivalent, close to planar conformations [C6/CO2 dihedral angle = 6.33 (14) and 3.43 (10)°]. The formation of hydroxy-O—H...N(pyridyl) hydrogen bonds between the benzoic acid molecules and the pyridyl residues of the diamide leads to a three-molecule aggregate. Centrosymmetrically related aggregates assemble into a six-molecule aggregate via amide-N—H...O(amide) hydrogen bonds through a 10-membered {...HNC2O}2 synthon. These are linked into a supramolecular tape via amide-N—H...O(carbonyl) hydrogen bonds and 22-membered {...HOCO...NC4NH}2 synthons. The contacts between tapes to consolidate the three-dimensional architecture are of the type methylene-C—H...O(amide) and pyridyl-C—H...O(carbonyl). These interactions are largely electrostatic in nature. Additional non-covalent contacts are identified from an analysis of the calculated Hirshfeld surfaces.


2015 ◽  
Vol 71 (10) ◽  
pp. 1159-1164 ◽  
Author(s):  
Chien Ing Yeo ◽  
Yee Seng Tan ◽  
Edward R. T. Tiekink

The crystal and molecular structures of the title salt, C8H8N3S2+·Cl−, (I), and salt hydrate, C8H7ClN3S2+·Cl−·H2O, (II), are described. The heterocyclic ring in (I) is statistically planar and forms a dihedral angle of 9.05 (12)° with the pendant phenyl ring. The comparable angle in (II) is 15.60 (12)°, indicating a greater twist in this cation. An evaluation of the bond lengths in the H2N—C—N—C—N sequence of each cation indicates significant delocalization of π-electron density over these atoms. The common feature of the crystal packing in (I) and (II) is the formation of charge-assisted amino-N—H...Cl−hydrogen bonds, leading to helical chains in (I) and zigzag chains in (II). In (I), these are linked by chains mediated by charge-assisted iminium-N+—H...Cl−hydrogen bonds into a three-dimensional architecture. In (II), the chains are linked into a layer by charge-assisted water-O—H...Cl−and water-O—H...O(water) hydrogen bonds with charge-assisted iminium-N+—H...O(water) hydrogen bonds providing the connections between the layers to generate the three-dimensional packing. In (II), the chloride anion and water molecules are resolved into two proximate sites with the major component being present with a site occupancy factor of 0.9327 (18).


2019 ◽  
Vol 234 (1) ◽  
pp. 43-57 ◽  
Author(s):  
Mukesh M. Jotani ◽  
James L. Wardell ◽  
Edward R.T. Tiekink

AbstractCrystallography reveals two polymorphs for the salt [4-(4-acetylphenyl)piperazin-1-ium][2-amino-4-nitrobenzoate], a monoclinic form (2; modelled asP21/nwith Z′=4) formed directly from the reaction mixture, and a triclinic form (1; Z′=1) isolated from recrystallisation. Relatively minor differences are noted in the conformations of the anions and of the cations, mainly relating to the twist of, respectively, the carboxylate groups and piperazin-1-ium rings with respect to the phenyl rings they are connected to. The key feature of the packing of both forms is the formation of charge-assisted ammonium-N–H···O (carboxylate) hydrogen bonds which lead to cyclic 12-membered {···HNH ···OCO}2synthons in the case of1but, supramolecular chains in2. The three-dimensional architecture in the crystal of1is further stabilised by amine-N–H···O (nitro) and amine-N–H···O (acetyl) hydrogen bonds, leading to double-layers in the bc-plane, which are linked along thea-axis by methylene-C–H···O (carboxylate) and π-stacking interactions. The combination of ammonium-N–H···O (carboxylate) and amine-N–H···O (carboxylate, acetyl) hydrogen bonds consolidate the three-dimensional packing in the crystal of2. The greater crystal density, packing efficiency and calculated lattice energy for1compared with2, suggest the former to be the thermodynamically most stable crystal. An analysis of the Hirshfeld surfaces for1and2reveal distinctive features that differentiate between the constituents of the two forms and between the ions comprising the asymmetric unit of2.


2016 ◽  
Vol 72 (12) ◽  
pp. 1700-1709 ◽  
Author(s):  
Mukesh M. Jotani ◽  
Hadi D. Arman ◽  
Pavel Poplaukhin ◽  
Edward R. T. Tiekink

The common feature of the molecular structures of the title compounds, [Zn(C5H10NS2)2(C5H5NO)], (I), and [Zn(C4H8NOS2)2(C5H5NO)], (II), are NS4donor sets derived fromN-bound hydroxypyridyl ligands and asymmetrically chelating dithiocarbamate ligands. The resulting coordination geometries are highly distorted, being intermediate between square pyramidal and trigonal bipyramidal for both independent molecules comprising the asymmetric unit of (I), and significantly closer towards square pyramidal in (II). The key feature of the molecular packing in (I) is the formation of centrosymmetric, dimeric aggregates sustained by pairs of hydroxy-O—H...S(dithiocarbamate) hydrogen bonds. The aggregates are connected into a three-dimensional architecture by methylene-C—H...O(hydroxy) and methyl-C—H...π(chelate) interactions. With greater hydrogen-bonding potential, supramolecular chains along thecaxis are formed in the crystal of (II), sustained by hydroxy-O—H...O(hydroxy) hydrogen bonds, with ethylhydroxy and pyridylhydroxy groups as the donors, along with ethylhydroxy-O—H...S(dithiocarbamate) hydrogen bonds. Chains are connected into layers in theacplane by methylene-C—H...π(chelate) interactions and these stack along thebaxis, with no directional interactions between them. An analysis of the Hirshfeld surfaces clearly distinguished the independent molecules of (I) and reveals the importance of the C—H...π(chelate) interactions in the packing of both (I) and (II).


2016 ◽  
Vol 72 (8) ◽  
pp. 1219-1222
Author(s):  
Md. Serajul Haque Faizi ◽  
Musheer Ahmad ◽  
Akram Ali ◽  
Vadim A. Potaskalov

The molecular shape of the title compound, C16H12O7, is bent around the central CH2—O bond. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 87.78 (7)°. In the crystal, each molecule is linked to three others by three pairs of O—H...O hydrogen bonds, forming undulating sheets parallel to thebcplane and enclosingR22(8) ring motifs. The sheets are linked by C—H...O hydrogen bonds and C—H...π interactions, forming a three-dimensional network.


2019 ◽  
Vol 234 (3) ◽  
pp. 165-175 ◽  
Author(s):  
Yee Seng Tan ◽  
Hao Zhe Chun ◽  
Mukesh M. Jotani ◽  
Edward R.T. Tiekink

Abstract The crystal and molecular structures of the one-dimensional coordination polymer [Zn(S2COEt)2(4LH2)]n (1) and binuclear [Zn(S2COCy)2]2(4LH2) (2) are described, where 4LH2 is N,N′-bis(pyridin-4-ylmethyl)ethanediamide. In 1, the Zn(S2COEt)2 entities are linked by bidentate bridging 4LH2 ligands through the pyridyl-N atoms to generate a twisted supramolecular chain. As a result of monodentate xanthate ligands, the N2S4 donor set defines a distorted tetrahedral coordination geometry and, crucially, allows the participation of the non-coordinating sulfur atoms in supramolecular association. Thus, in the crystal amide-N–H···O(amide) and amide-N–H···S(thione) hydrogen bonds link chains into a three-dimensional architecture. The substitution of the ethyl group in the xanthate ligand with a cyclohexyl group results in very different structural outcomes. In 2, a binuclear molecule is observed with the coordination geometry for zinc being defined by chelating xanthate ligands and a pyridyl-N atom with the NS4 donor set defining a highly distorted geometry. In the molecular packing, amide-N–H···S(thione) hydrogen bonds stabilise a supramolecular chain along the a-axis and these are connected into a three-dimensional arrangement by methylene-C–H···O and methylene-C–H···π(pyridyl) interactions. The relative importance of the specified intermolecular interactions and weaker, contributing contacts has been revealed by an analysis of the calculated Hirshfeld surfaces of 1 and 2.


Author(s):  
H. Purandara ◽  
Sabine Foro ◽  
B. Thimme Gowda

The title acylhydrazone derivative, C17H19N3O3S, containing an amino acid moiety and electron-donating substituents attached to both the phenyl rings, crystallized with two independent molecules (AandB) in the asymmetric unit. The molecules are bent at the S atom, with C—SO2—NH—CH2torsion angles of −67.3 (2) and 67.7 (3)° in moleculesAandB, respectively. Further, the dihedral angles between the sulfonylglycine segments and thep-toluenesulfonyl rings are 76.1 (1) and 85.8 (1)° in moleculesAandB, respectively. The central hydrazone segments and the toluene rings attached to them are almost co-planar with their mean planes being inclined to one another by 5.2 (2) (moleculeA) and 2.9 (2)° (moleculeB). The dihedral angles between the benzene rings are 86.83 (12) (moleculeA) and 74.00 (14)° (moleculeB). In the crystal, theAmolecules are linked by a pair of N—H...O hydrogen bonds, forming inversion dimers with anR22(8) ring motif. The dimers are linkedviathree N—H...O hydrogen bonds involving theBmolecules, forming chains along [100] and enclosingR22(12) andR44(16) ring motifs. The chains are linkedviaC—H...O hydrogen bonds and a C—H...π interaction, forming sheets parallel to (010). There is a further C—H...π interaction and a slipped parallel π–π interaction [inter-centroid distance = 3.8773 (16) Å] between the sheets, leading to the formation of a three-dimensional framework.


Author(s):  
Trung Vu Quoc ◽  
Duong Tran Thi Thuy ◽  
Thuan Dang Thanh ◽  
Thanh Phung Ngoc ◽  
Vuong Nguyen Thien ◽  
...  

The synthesis, spectroscopic data and crystal and molecular structures of four 3-(3-phenylprop-1-ene-3-one-1-yl)thiophene derivatives, namely 1-(4-hydroxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H10O2S, (1), 1-(4-methoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C14H12O2S, (2), 1-(4-ethoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C15H14O2S, (3), and 1-(4-bromophenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H9BrOS, (4), are described. The four chalcones have been synthesized by reaction of thiophene-3-carbaldehyde with an acetophenone derivative in an absolute ethanol solution containing potassium hydroxide, and differ in the substituent at the para position of the phenyl ring: –OH for 1, –OCH3 for 2, –OCH2CH3 for 3 and –Br for 4. The thiophene ring in 4 was found to be disordered over two orientations with occupancies 0.702 (4) and 0.298 (4). The configuration about the C=C bond is E. The thiophene and phenyl rings are inclined by 4.73 (12) for 1, 12.36 (11) for 2, 17.44 (11) for 3 and 46.1 (6) and 48.6 (6)° for 4, indicating that the –OH derivative is almost planar and the –Br derivative deviates the most from planarity. However, the substituent has no real influence on the bond distances in the α,β-unsaturated carbonyl moiety. The molecular packing of 1 features chain formation in the a-axis direction by O—H...O contacts. In the case of 2 and 3, the packing is characterized by dimer formation through C—H...O interactions. In addition, C—H...π(thiophene) interactions in 2 and C—H...S(thiophene) interactions in 3 contribute to the three-dimensional architecture. The presence of C—H...π(thiophene) contacts in the crystal of 4 results in chain formation in the c-axis direction. The Hirshfeld surface analysis shows that for all four derivatives, the highest contribution to surface contacts arises from contacts in which H atoms are involved.


2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.


2018 ◽  
Vol 74 (12) ◽  
pp. 1891-1894
Author(s):  
Priya Antony ◽  
S. Antony Inglebert ◽  
Jerald V. Ramaclus ◽  
S. John Sundaram ◽  
P. Sagayaraj

The title molecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S−·H2O, (II), are stilbazole, or 4-styrylpyridine, derivatives. The cation, (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic molecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetrahedral coordination sphere. In (II), the anion consists of a 4-methoxybenzenesulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π–π stacking interactions involving the pyridinium and benzene rings, with centroid–centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-methoxybenzenesulfonate anions are bridged by Owater—H...Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C—H...O hydrogen bonds, forming slabs lying parallel to the ab plane.


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