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Crystal structures of N-(pyridin-2-ylmeth-yl)pyrazine-2-carboxamide (monoclinic polymorph) and N-(pyridin-4-ylmeth-yl)pyrazine-2-carboxamide.

Cati DS, Stoeckli-Evans H - Acta Crystallogr Sect E Struct Rep Online (2014)

Bottom Line: Monatsh.Within the sheets there are π-π inter-actions involving neighbouring pyrazine rings [inter-centroid distance = 3.711 (15) Å].Adjacent sheets are linked via parallel slipped π-π inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.6395 (17) Å], forming a three-dimensional structure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Debiopharm International S.A., Chemin Messidor 5-7, CP 5911, CH-1002 Lausanne, Switzerland.

ABSTRACT
The title compounds, C11H10N4O (HL1) and C11H10N4O (HL2), are pyridine 2-ylmethyl and 4-ylmethyl derivatives, respectively, of pyrazine-2-carboxamide. HL1 was measured at 153 K and crystallized in the monoclinic space group P21/c with Z = 4. There has been a report of the same structure measured at room temperature but assumed to crystallize in the triclinic space group P-1 with Z = 4 [Sasan et al. (2008 ▶). Monatsh. Chem. 139, 773-780]. In HL1, the pyridine ring is inclined to the pyrazine ring by 61.34 (6)°, while in HL2 this dihedral angle is 84.33 (12)°. In both mol-ecules, there is a short N-H⋯N inter-action involving the pyrazine carboxamide unit. In the crystal of HL1, mol-ecules are linked by N-H⋯N hydrogen bonds, forming inversion dimers with an R 2 (2)(10) ring motif. The dimers are linked via bifurcated-acceptor C-H⋯O hydrogen bonds, forming sheets lying parallel to (102). The sheets are linked via C-H⋯N hydrogen bonds, forming a three-dimensional structure. In the crystal of HL2, mol-ecules are linked by N-H⋯N and C-H⋯N hydrogen bonds to form chains propagating along [010]. The chains are linked via C-H⋯O hydrogen bonds, forming sheets lying parallel to (100). Within the sheets there are π-π inter-actions involving neighbouring pyrazine rings [inter-centroid distance = 3.711 (15) Å]. Adjacent sheets are linked via parallel slipped π-π inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.6395 (17) Å], forming a three-dimensional structure.

No MeSH data available.


A view of the mol­ecular structure of HL1, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The short intra­molecular N—H⋯N inter­action is shown as a dashed line (see Table 1 ▶ for details).
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fig1: A view of the mol­ecular structure of HL1, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The short intra­molecular N—H⋯N inter­action is shown as a dashed line (see Table 1 ▶ for details).

Mentions: The mol­ecular structure of ligand HL1 is illustrated in Fig. 1 ▶. HL1 was measured at 153 K and crystallized in the monoclinic space group P21/c with Z = 4. The β angle is 91.461 (11)° and the systematic absences, the Rint value (0.0348) and the successful refinement {R1 [I > 2σ(I)] = 0.0319} clearly show that at 153 K the space group is monoclinic P21/c. The same structure measured at room temperature was reported to crystallize in the triclinic space group P with Z = 4 (Sasan et al., 2008 ▶). However, the three cell angles are close 90 (2)° [α = 91.802 (6), β = 89.834 (7), γ = 91.845 (6)°] and the crystal used was a very narrow needle. The final R1 [I > 2σ(I)] factor was rather high at 0.0699, hence it is possible that the choice of crystal system and space group are incorrect. However, this could not be confirmed when analysing the coordinates using the AddSymm routine in PLATON (Spek, 2009 ▶).


Crystal structures of N-(pyridin-2-ylmeth-yl)pyrazine-2-carboxamide (monoclinic polymorph) and N-(pyridin-4-ylmeth-yl)pyrazine-2-carboxamide.

Cati DS, Stoeckli-Evans H - Acta Crystallogr Sect E Struct Rep Online (2014)

A view of the mol­ecular structure of HL1, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The short intra­molecular N—H⋯N inter­action is shown as a dashed line (see Table 1 ▶ for details).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120586&req=5

fig1: A view of the mol­ecular structure of HL1, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The short intra­molecular N—H⋯N inter­action is shown as a dashed line (see Table 1 ▶ for details).
Mentions: The mol­ecular structure of ligand HL1 is illustrated in Fig. 1 ▶. HL1 was measured at 153 K and crystallized in the monoclinic space group P21/c with Z = 4. The β angle is 91.461 (11)° and the systematic absences, the Rint value (0.0348) and the successful refinement {R1 [I > 2σ(I)] = 0.0319} clearly show that at 153 K the space group is monoclinic P21/c. The same structure measured at room temperature was reported to crystallize in the triclinic space group P with Z = 4 (Sasan et al., 2008 ▶). However, the three cell angles are close 90 (2)° [α = 91.802 (6), β = 89.834 (7), γ = 91.845 (6)°] and the crystal used was a very narrow needle. The final R1 [I > 2σ(I)] factor was rather high at 0.0699, hence it is possible that the choice of crystal system and space group are incorrect. However, this could not be confirmed when analysing the coordinates using the AddSymm routine in PLATON (Spek, 2009 ▶).

Bottom Line: Monatsh.Within the sheets there are π-π inter-actions involving neighbouring pyrazine rings [inter-centroid distance = 3.711 (15) Å].Adjacent sheets are linked via parallel slipped π-π inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.6395 (17) Å], forming a three-dimensional structure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Debiopharm International S.A., Chemin Messidor 5-7, CP 5911, CH-1002 Lausanne, Switzerland.

ABSTRACT
The title compounds, C11H10N4O (HL1) and C11H10N4O (HL2), are pyridine 2-ylmethyl and 4-ylmethyl derivatives, respectively, of pyrazine-2-carboxamide. HL1 was measured at 153 K and crystallized in the monoclinic space group P21/c with Z = 4. There has been a report of the same structure measured at room temperature but assumed to crystallize in the triclinic space group P-1 with Z = 4 [Sasan et al. (2008 ▶). Monatsh. Chem. 139, 773-780]. In HL1, the pyridine ring is inclined to the pyrazine ring by 61.34 (6)°, while in HL2 this dihedral angle is 84.33 (12)°. In both mol-ecules, there is a short N-H⋯N inter-action involving the pyrazine carboxamide unit. In the crystal of HL1, mol-ecules are linked by N-H⋯N hydrogen bonds, forming inversion dimers with an R 2 (2)(10) ring motif. The dimers are linked via bifurcated-acceptor C-H⋯O hydrogen bonds, forming sheets lying parallel to (102). The sheets are linked via C-H⋯N hydrogen bonds, forming a three-dimensional structure. In the crystal of HL2, mol-ecules are linked by N-H⋯N and C-H⋯N hydrogen bonds to form chains propagating along [010]. The chains are linked via C-H⋯O hydrogen bonds, forming sheets lying parallel to (100). Within the sheets there are π-π inter-actions involving neighbouring pyrazine rings [inter-centroid distance = 3.711 (15) Å]. Adjacent sheets are linked via parallel slipped π-π inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.6395 (17) Å], forming a three-dimensional structure.

No MeSH data available.