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
Abstract
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.
Citation
Chinthal , C H , Kavitha , C N , Yathirajan , H S , Foro , S & Glidewell , C 2021 , ' 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 ' , Acta Crystallographica Section E Crystallographic Communications , vol. 77 , no. 1 , pp. 5-13 . https://doi.org/10.1107/S2056989020015649
Publication
Acta Crystallographica Section E Crystallographic Communications
Status
Peer reviewed
ISSN
2056-9890Type
Journal article
Rights
Copyright © 2020 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Description
HSY thanks the University Grants Commission, New Delhi for the award of a BSR Faculty Fellowship for three years.Collections
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