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Crystal structure of a second triclinic polymorph of 2-methyl-pyridinium picrate.

Gomathi J, Kalaivani D - Acta Crystallogr E Crystallogr Commun (2015)

Bottom Line: Acta Cryst.CrystEngComm, 16, 4508-4538].It is inter-esting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

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Affiliation: PG and Research Department of Chemistry, Seethalakshmi Ramaswami College, Tiruchirappalli 620 002, Tamil Nadu, India.

ABSTRACT
The title mol-ecular salt, C6H8N(+)·C6H2N3O7 (-) (systematic name: 2-methyl-pyridinium 2,4,6-tri-nitro-phenolate), crystallizes with two cations and two anions in the asymmetric unit. In the crystal, the cations are linked to the anions via bifurcated N-H⋯(O,O) hydrogen bonds, generating R 1 (2)(6) graph-set motifs. Numerous C-H⋯O hydrogen bonds are observed between these cation-anion pairs, which result in a three-dimensional network. In addition, weak aromatic π-π stacking between the 2-methyl-pyridinium rings [inter-centroid distance = 3.8334 (19) Å] and very weak stacking [inter-centroid distance = 4.0281 (16) Å] between inversion-related pairs of picrate anions is observed. The title salt is a second triclinic polymorph of the structure (also with Z' = 2) reported earlier [Anita et al. (2006). Acta Cryst. C62, o567-o570; Chan et al. (2014 ▸). CrystEngComm, 16, 4508-4538]. In the title compound, the cations and anions display a chequerboard arrangement when viewed down [100], whereas in the first polymorph, (010) layers of alternating cations and anions are apparent in a [100] view. It is inter-esting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

No MeSH data available.


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ORTEP view of the title molecular salt with displacement ellipsoids drawn at 40% probability.
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Fap1: ORTEP view of the title molecular salt with displacement ellipsoids drawn at 40% probability.


Crystal structure of a second triclinic polymorph of 2-methyl-pyridinium picrate.

Gomathi J, Kalaivani D - Acta Crystallogr E Crystallogr Commun (2015)

ORTEP view of the title molecular salt with displacement ellipsoids drawn at 40% probability.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645006&req=5

Fap1: ORTEP view of the title molecular salt with displacement ellipsoids drawn at 40% probability.
Bottom Line: Acta Cryst.CrystEngComm, 16, 4508-4538].It is inter-esting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

View Article: PubMed Central - HTML - PubMed

Affiliation: PG and Research Department of Chemistry, Seethalakshmi Ramaswami College, Tiruchirappalli 620 002, Tamil Nadu, India.

ABSTRACT
The title mol-ecular salt, C6H8N(+)·C6H2N3O7 (-) (systematic name: 2-methyl-pyridinium 2,4,6-tri-nitro-phenolate), crystallizes with two cations and two anions in the asymmetric unit. In the crystal, the cations are linked to the anions via bifurcated N-H⋯(O,O) hydrogen bonds, generating R 1 (2)(6) graph-set motifs. Numerous C-H⋯O hydrogen bonds are observed between these cation-anion pairs, which result in a three-dimensional network. In addition, weak aromatic π-π stacking between the 2-methyl-pyridinium rings [inter-centroid distance = 3.8334 (19) Å] and very weak stacking [inter-centroid distance = 4.0281 (16) Å] between inversion-related pairs of picrate anions is observed. The title salt is a second triclinic polymorph of the structure (also with Z' = 2) reported earlier [Anita et al. (2006). Acta Cryst. C62, o567-o570; Chan et al. (2014 ▸). CrystEngComm, 16, 4508-4538]. In the title compound, the cations and anions display a chequerboard arrangement when viewed down [100], whereas in the first polymorph, (010) layers of alternating cations and anions are apparent in a [100] view. It is inter-esting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

No MeSH data available.


Related in: MedlinePlus