4-[Bis(4-fluorophenyl)methyl]piperazin-1-ium 2-(2-phenylethyl)benzoate

The asymmetric unit of the title salt, C17H19F2N2 +.C15H13O2 −, derived from a 1,4-diaza­cyclo­hexane derivative and a carb­oxy­lic acid, contains two formula units. The cation is protonated at the secondary amine functionality. The six-membered heterocycles adopt chair conformations. The fluorophenyl rings in the two cations make dihedral angles of 77.21 (19) and 78.8 (2)° while the aromatic rings in the anions enclose angles of 69.5 (2) and 69.9 (2)°. In the crystal, classical N—H⋯O hydrogen bonds as well as C—H⋯F and C—H⋯O contacts connect the entities into layers parallel to ac

Crystal structures of two C,N-disubstituted acetamides: 2-(4-chlorophenyl)-N-(2-iodophenyl)acetamide and 2-(4-chlorophenyl)-N-(pyrazin-2-yl)acetamide

BN thanks the UGC (India) for financial assistance through a BSR one-time grant for the purchase of chemicals.In the crystal of 2-(4-chloro­phen­yl)-N-(2-iodo­phen­yl)acetamide, C14H11ClINO, molecules are linked by a combination of N—H⋯O and C—H⋯O hydrogen bonds to form a C(4)C(4)[R21(7)] chain of rings and chains of this type are linked by a combination of C—Cl⋯π(arene) and C—I⋯π(arene) inter­actions to form deeply puckered twofold inter­woven sheets. In the crystal of 2-(4-chloro­phen­yl)-N-(pyrazin-2-yl)acetamide, C12H10ClN3O, mol­ecules are linked into complex sheets by N—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds, and by C—H⋯π(arene) inter­actions.Publisher PDFPeer reviewe

3-Chloro-N-(4-meth­oxy­phen­yl)propanamide

The title compound, C10H12ClNO2, is a halogenated derivative of a secondary amide bearing an aromatic substituent. The C(=O)—N(H)—Car—Car torsion angle of −33.70 (18)° rules out the presence of resonance spanning the amide as well as the aromatic system. In the crystal, classical N—H⋯O hydrogen bonds, as well as C–H⋯O contacts connect the mol­ecules into chains propagating along the a axis

Reinvestigation of the crystal structure of it N-(4-chlorobenzylidene)-2-hydroxyaniline : a three-dimensional structure containing O—H···N, O—H···O and C—H···π(arene) hydrogen bonds

MG thanks the UGC (India) for the award of a Rajeev Gandhi fellowship.The molecule of the title compound, C13H10ClNO, (I), which contains an intramolecular O—H···N hydrogen bond, is almost planar: the dihedral angle between the two aryl rings is only 3.31 (9)°. The molecules of (I) are linked into sheets by two C—H···π(arene) hydrogen bonds and the sheets are linked into a three-dimensional structure by O—H···O hydrogen bonds. Comparisons are made with the structures of a number of related compounds.Publisher PDFPeer reviewe

Order versus disorder in two isomorphous pyrazolone-substituted di­ethyl propane­dioates prepared using a three-component one-pot reaction under solvent-free conditions

Funding for this research was provided by: University Grants Commission, New Delhi.Two new substituted propane­dioate esters have been synthesized using a three-component solvent-free thermal reaction between diethyl propane­dioate (diethyl malonate), 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and an aryl azide, forming two new C—C bonds in a single step. The products diethyl (RS)-2-[(4-bromo­phen­yl)(5-methyl-3-oxo-2-phenyl-2,3-di­hydro-1H-pyrazol-4-yl)meth­yl]propane­dioate, C24H25BrN2O5 (I), and diethyl (RS)-2-[(4-chloro­phen­yl)(5-methyl-3-oxo-2-phenyl-2,3-di­hydro-1H-pyrazol-4-yl)meth­yl]propane­dioate, C24H25ClN2O5 (II), are isomorphous, with Z′ = 2 in space group P21/n. The two independent mol­ecules in compound (I) are both fully ordered, while each of the independent mol­ecules in compound (II) is disordered, but in different ways. In one mol­ecule of (II), the N-phenyl ring is disordered over two sets of atomic sites having occupancies 0.635 (10) and 0.365 (10), and in the other mol­ecule the ester function is disordered over two sets of atomic sites having occupancies 0.690 (5) and 0.310 (5). In both structures, the two independent mol­ecules adopt different conformations and, in each structure, the mol­ecules are linked into complex sheets by a combination of N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds. Comparisons are made with some related structures.Publisher PDFPeer reviewe

4-[(1E)-3-(2,6-Dichloro-3-fluoro­phen­yl)-3-oxoprop-1-en-1-yl]benzonitrile

In the title mol­ecule, C16H8Cl2FNO, the benzene rings form a dihedral angle of 78.69 (8)°. The F atom is disordered over two positions in a 0.530 (3):0.470 (3) ratio. The crystal packing exhibits π–π inter­actions between dichloro-substituted rings [centroid–centroid distance = 3.6671 (10) Å] and weak inter­molecular C—H⋯F contacts

Six 1-halobenzoyl-4-(2-methoxyphenyl)piperazines having Z' values of one, two or four; disorder, pseudosymmetry, twinning and supramolecular assembly in one, two or three dimensions

HSY thanks the University Grants Commission, New Delhi for the award of a BSR Faculty Fellowship for three years.Six 1-halobenzoyl-4-(2-methoxyphenyl)piperazines have been prepared using carbodiimide-mediated coupling reactions between halobenzoic acids and N-(2-methoxyphenyl)piperazine. The molecules of 1-(4-fluorobenzoyl)-4-(2-methoxyphenyl)piperazine, C18H19FN2O2 (I), are linked into a chain of rings by a combination of C-H···O and C-H···π(arene) hydrogen bonds. 1-(4-Chloro-benzoyl)-4-(2-methoxyphenyl)piperazine, C18H19ClN2O2 (II), crystallizes in the space group Pca21 with Z' = 4 and it exhibits both pseudosymmetry and inversion twinning: a combination of six C-Six 1-halobenzoyl-4-(2-meth­oxy­phen­yl)piperazines have been prepared using carbodi­imide-mediated coupling reactions between halo­benzoic acids and N-(2-meth­oxy­phen­yl)piperazine. The mol­ecules of 1-(4-fluoro­benzo­yl)-4-(2-meth­oxy­phen­yl)piperazine, C18H19FN2O2 (I), are linked into a chain of rings by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds. 1-(4-Chloro­benzo­yl)-4-(2-meth­oxy­phen­yl)piperazine, C18H19ClN2O2 (II), crystallizes in the space group Pca21 with Z′ = 4 and it exhibits both pseudosymmetry and inversion twinning: a combination of six C—H⋯O and two C—H⋯π(arene) hydrogen bonds generate a three-dimensional assembly. In 1-(4-bromo­benzo­yl)-4-(2-meth­oxy­phen­yl)piperazine, C18H19BrN2O2 (III), which also crystallizes in space group Pca21 but with Z′ = 2, the bromo­benzoyl unit in one of the mol­ecules is disordered. Pseudosymmetry and inversion twinning are again present, and a combination of three C—H⋯O and one C—H⋯π(arene) hydrogen bonds generate a two-dimensional assembly. A single C—H⋯O hydrogen bond links the mol­ecules of 1-(4-iodo­benzo­yl)-4-(2-meth­oxy­phen­yl)piperazine, C18H19IN2O2 (IV), into simple chains but in the isomeric 3-iodo­benzoyl analogue (V), which crystallizes in space group P212121 with Z′ = 2, a two-dimensional assembly is generated by a combination of four C—H⋯O and two C—H⋯π(arene) hydrogen bonds; pseudosymmetry and inversion twinning are again present. A single C—H⋯O hydrogen bond links the mol­ecules of 1-(2-fluoro­benzo­yl)-4-(2-meth­oxy­phen­yl)piperazine, C18H19FN2O2 (VI), into simple chains. Comparisons are made with the structures of some related compounds.H center dot center dot center dot O and two C-H center dot center dot center dot pi(arene) hydrogen bonds generate a three-dimensional assembly. In 1-(4-bromobenzoyl)4-(2-methoxyphenyl)piperazine, C18H19BrN2O2 (III), which also crystallizes in space group Pca2(1) but with Z' = 2, the bromobenzoyl unit in one of the molecules is disordered. Pseudosymmetry and inversion twinning are again present, and a combination of three C-H···O and one C-H···π(arene) hydrogen bonds generate a two-dimensional assembly. A single C-H···O hydrogen bond links the molecules of 1-(4-iodobenzoyl)-4-(2-methoxyphenyl)piperazine, C18H19IN2O2 (IV), into simple chains but in the isomeric 3-iodobenzoyl analogue (V), which crystallizes in space group P212121 with Z' = 2, a two-dimensional assembly is generated by a combination of four C-H··· O and two C-H ···π(arene) hydrogen bonds; pseudosymmetry and inversion twinning are again present. A single C-H ···O hydrogen bond links the molecules of 1-(2-fluorobenzoyl)-4-(2-methoxyphenyl)piperazine, C18H19FN2O2 (VI), into simple chains. Comparisons are made with the structures of some related compounds.Publisher PDFPeer reviewe

Crystal structures of N,N-dimethyl-(2-(2,2-diphenyl)-2-prop-2-ynyloxy)acetoxy)ethylamine and N,N-dimethyl-(2-(2,2-diphenyl)-2-prop-2-ynyloxy)acetoxy)ethylammonium 2,4,6-trinitrophenolate

The N,N-dimethylethylamminium unit in N,N-dimethyl-[2-(2,2-diphenyl)-2-prop-2-ynyloxyacetoxy]ethylamine, C21H23NO3 (I), is disordered over two sets of atomic sites having occupancies of 0.880 (3) and 0. 120 (3), but there are no direction-specific interactions between the molecules of (I). The cation in N,N-dimethyl-[2-(2,2-diphenyl)-2-prop-2-ynyloxyacetoxy]ethylammonium 2,4,6-trinitrophenolate (picrate), C21H24NO3+·C6H2N3O7- (II), shows a similar type of disorder, with occupancies of 0.654 (11) and 0.346 (11), although the overall conformation of the cation in (II) is different from that in the neutral (I). The component ions are are linked by an almost planar three-centre N—H···(O)2 hydrogen bond, and the ion pairs are further linked by a combination of three C—H···O hydrogen bonds to form sheets. Comparisons are made with some related structures.Publisher PDFPeer reviewe

Two 3-amino-1H-pyrazol-2-ium salts containing organic anions, and an orthorhombic polymorph of 3-amino-1H-pyrazol-2-ium nitrate

HSY thanks the University Grants Commission, New Delhi for the award of a BSR Faculty Fellowship for three years.Co-crystallization from methanol of 3-amino-1H-pyrazole with 3,5-dinitro-benzoic acid produces 3-amino-1H-pyrazol-2-ium 3,5-dinitrobenzoate mono-hydrate, C3H6N3+.C7H3N2O6-center dot H2O, (I), while similar co-crystallization of this pyrazole with an equimolar quantity of fumaric acid produces bis(3-amino-1H-pyrazol- 2-ium) fumarate-fumaric acid (1/1), 2C(3)H(6)N(3)(+)center dot C4H2O42-center dot C4H4O4, (II). The reaction of 3-amino-1H-pyrazole with a dilute solution of nitric acid in methanol yields a second, orthorhombic polymorph of 3-amino-1H-pyrazol-2-ium nitrate, C3H6N3+center dot NO3-, (III). In each of (I)-(III), the bond distances in the cation provide evidence for extensive delocalization of the positive charge. In each of (I) and (II), an extensive series of O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds links the components into complex sheets, while in the structure of (III), the ions are linked by multiple N-H center dot center dot center dot O hydrogen bonds into a threedimensional arrangement. Comparisons are made with the structures of some related compounds.Publisher PDFPeer reviewe

Crystal structure of ebastinium 3,5-dinitrobenzoate

BKS thanks the UGC for the award of a Rajiv Gandhi National Fellowship.Ebastine, 4-(benzhydryloxy)-1-[4-(4-tert-butylphenyl)-4-oxobutyl]piperidine, reacts with 3,5-dinitrobenzoic acid in methanol solution to give the title 1:1 salt, ebastinium 3,5-dinitrobenzoate, C32H40NO2+·C7H3N2O6-. In the cation, the disubstituted aryl ring exhibits orientational disorder over two sets of atomic sites having occupancies 0.706(4) and 0.294(6), with a dihedral angle of 41.2(5)° between the two orientations: the bulky Ph2CH—O– substituent occupies an axial site on the piperidine ring. The two ions in the selected asymmetric unit are linked by a nearly linear N—H···O hydrogen bond and this, in combination with two C—H···O hydrogen bonds, links the ions into complex sheets.Publisher PDFPeer reviewe