Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate
Crystallography reveals two polymorphs for the salt [4-(4- acetylphenyl)piperazin-1-ium][2-amino-4-nitrobenzoate], a monoclinic form (2; modelled as P21/n with Z' = 4) formed directly from the reaction mixture, and a triclinic form (1; Z' = 1) isolated from recrystallisation. Relatively m...
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| Format: | Article |
| Language: | English |
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De Gruyter for Oldenbourgh Verlag
2019
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| Online Access: | http://eprints.sunway.edu.my/988/ http://eprints.sunway.edu.my/988/1/Tiekink%20Supramolecular%20Z%20Kristallogr%202019%20234%2043%20final%20version.pdf |
| _version_ | 1848801965259096064 |
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| author | Jotani, Mukesh M. Wardell, James L. Tiekink, Edward R. T. * |
| author_facet | Jotani, Mukesh M. Wardell, James L. Tiekink, Edward R. T. * |
| author_sort | Jotani, Mukesh M. |
| building | SU Institutional Repository |
| collection | Online Access |
| description | Crystallography reveals two polymorphs for the salt [4-(4-
acetylphenyl)piperazin-1-ium][2-amino-4-nitrobenzoate], a monoclinic form (2; modelled as P21/n with 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}2 synthons in the case of
1 but, supramolecular chains in 2. The three-dimensional architecture in the crystal of 1 is 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 the a-axis by methylene-C10‒H…O(carboxylate) and -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 of 2. The greater crystal
density, packing efficiency and calculated lattice energy for 1 compared with 2, suggest the former to be the thermodynamically most stable crystal.
An analysis of the Hirshfeld surfaces for 1 and 2 reveal distinctive features that differentiate between the constituents of the two forms and between the ions comprising the asymmetric unit of 2. |
| first_indexed | 2025-11-14T21:15:50Z |
| format | Article |
| id | sunway-988 |
| institution | Sunway University |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T21:15:50Z |
| publishDate | 2019 |
| publisher | De Gruyter for Oldenbourgh Verlag |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | sunway-9882020-10-07T08:55:53Z http://eprints.sunway.edu.my/988/ Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate Jotani, Mukesh M. Wardell, James L. Tiekink, Edward R. T. * QD Chemistry Crystallography reveals two polymorphs for the salt [4-(4- acetylphenyl)piperazin-1-ium][2-amino-4-nitrobenzoate], a monoclinic form (2; modelled as P21/n with 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}2 synthons in the case of 1 but, supramolecular chains in 2. The three-dimensional architecture in the crystal of 1 is 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 the a-axis by methylene-C10‒H…O(carboxylate) and -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 of 2. The greater crystal density, packing efficiency and calculated lattice energy for 1 compared with 2, suggest the former to be the thermodynamically most stable crystal. An analysis of the Hirshfeld surfaces for 1 and 2 reveal distinctive features that differentiate between the constituents of the two forms and between the ions comprising the asymmetric unit of 2. De Gruyter for Oldenbourgh Verlag 2019 Article PeerReviewed text en http://eprints.sunway.edu.my/988/1/Tiekink%20Supramolecular%20Z%20Kristallogr%202019%20234%2043%20final%20version.pdf Jotani, Mukesh M. and Wardell, James L. and Tiekink, Edward R. T. * (2019) Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate. Zeitschrift fur Kristallographie, 234 (1). pp. 43-57. ISSN 0044-2968 (In Press) |
| spellingShingle | QD Chemistry Jotani, Mukesh M. Wardell, James L. Tiekink, Edward R. T. * Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title | Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title_full | Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title_fullStr | Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title_full_unstemmed | Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title_short | Supramolecular association in the triclinic (Z′ = 1) and monoclinic (Z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| title_sort | supramolecular association in the triclinic (z′ = 1) and monoclinic (z′ = 4) polymorphs of 4-(4-acetylphenyl)piperazin-1-ium 2-amino4-nitrobenzoate |
| topic | QD Chemistry |
| url | http://eprints.sunway.edu.my/988/ http://eprints.sunway.edu.my/988/1/Tiekink%20Supramolecular%20Z%20Kristallogr%202019%20234%2043%20final%20version.pdf |