The crystal structure of 1-(2-iodobenzoyl)-4-(pyrimidin-2-yl)piperazine : a three-dimensional hydrogen-bonded framework, augmented by π-π stacking interactions and I···N halogen bonds

HSY is grateful to the UGC, New Delhi for the award of a BSR Faculty Fellowship for three years.In 1-(2-iodo­benzo­yl)-4-(pyrimidin-2-yl)piperazine, C15H 15IN 4O, the central piperazine ring adopts an almost perfect chair conformation with the pyrimidine substituent in an equatorial site. The planar amide unit makes a dihedral angle of 80.44 (7)° with the phenyl ring. A combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds links the mol­ecules into a complex three-dimensional network structure, augmented by a π– π stacking inter­action and an I⋯N halogen bond, all involving different pairs of inversion-related mol­ecules. Comparisons are made with the structures of a number of related compounds.Publisher PDFPeer reviewe

Three closely related 1-[(1,3-benzodioxol-5-yl)methyl]-4-(halobenzoyl)piperazines : similar molecular structures but different intermolecular interactions

HSY is grateful to the UGC, New Delhi for the award of a BSR Faculty Fellowship for three years. BKS thanks the UGC for the award of a Rajeev Gandhi Fellowship.In each of the compounds 1-[(1,3-benzodioxol-5-yl)methyl]-4-(3-fluoro­benzo­yl)piperazine, C19H 19FN 2O 3 (I), 1-[(1,3-benzodioxol-5-yl)methyl]-4-(2,6-di­fluoro­benzo­yl)piperazine, C19H 18F 2N 2O 3 (II), and 1-[(1,3-benzodioxol-5-yl)methyl]-4-(2,4-di­chloro­benzo­yl)piperazine, C19H 19Cl 2N 2O 3 (III), the piperazine rings adopt a chair conformation with the (1,3-benzodioxol-5-yl)methyl substituent occupying an equatorial site: the five-membered rings are all slightly folded across the O⋯O line leading to envelope conformations. The dihedral angle between the planar amidic fragment and the haloaryl ring is 62.97 (5)° in (I) but 77.72 (12)° and 75.50 (5)° in (II) and (III), respectively. Despite their similarity in constitution and conformation, the supra­molecular inter­actions in (I)–(III) differ: in (I), a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds links the mol­ecules into a three-dimensional framework structure, but there are no hydrogen bonds of any sort in either (II) or (III), although the structure of (III) contains a short Cl⋯Cl contact between inversion-related pairs of mol­ecules.Publisher PDFPeer reviewe

Co-crystallization of 3,5-dinitrobenzoic acid with two antipsychotic agents : a simple 1:1 salt with trihexyphenidyl and a 1:2 acid salt containing a very short O-H···O hydrogen bond with chlorprothixene

HSY is grateful to the UGC, New Delhi, for the award of a BSR Faculty Fellowship for three years.Co-crystallization of racemic 1-cyclo­hexyl-1-phenyl-3-(piperidin-1-yl)propan-1-ol (trihexyphenid­yl) with 3,5-di­nitro­benzoic acid gives a simple 1:1 salt, namely 1-(3-cyclo­hexyl-3-hy­droxy-3-phenyl­prop­yl)piperidin-1-ium 3,5-di­nitro­benzoate, C20H 32NO +·C 7H 3N 2O 6 −, (I), whereas a similar co-crystallization using (Z)-3-(2-chloro-9 H-thioxanthen-9-yl)- N, N-di­methyl­propan-1-amine (chlorprothixene) gives a 1:2 acid salt, namely (Z)-3-(2-chloro-9 H-thioxanthen-9-yl)- N, N-di­methyl­propan-1-aminium hydrogen bis­(3,5-di­nitro­benzoate), C18H 19ClNS +·[H(C 7H 3N 2O 6) 2] −, (II), the anion of which contains a very short O—H⋯O hydrogen bond, with dimensions O—H = 1.04 (3) Å, H⋯O = 1.41 (3) Å, O⋯O = 2.4197 (15) Å and O—H⋯O = 161 (3)°. In the cation of (I), the cyclo­hexyl and piperidyl rings both adopt chair conformations, whereas in the cation of (II), the central heterocyclic ring adopts a boat conformation, so that the dihedral angle between the two aryl rings is 41.56 (4)°. A combination of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds links the ions of (I) into a complex chain of rings, and these chains are linked into sheets by π– π stacking inter­actions between inversion-related pairs of anions. In compound (II), a different combination of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds links the ions into sheets. Comparisons are made with some related structures.Publisher PDFPeer reviewe

Methyl 1-methyl-1H-indole-3-carboxyl­ate

The title indole derivative, C11H11NO2, was synthesized from 1-methyl-1H-indole-3-carb­oxy­lic acid and methanol. The mol­ecule is planar as it is situated on a mirror plane present in the space group Pbcm. In the crystal, mol­ecules form three kinds of inter­molecular C—H⋯O hydrogen bonds, resulting in a sheet structure in the ab plane. Parallel sheets inter­act by C—H⋯π stacking, stabilizing the crystal packing