Crystal structure of a pyrazine-2,3-dicarboxamide ligand and of its silver(I) nitrate complex, a three-dimensional coordination polymer

Acta Crystallographica Section E: Crystallographic Communications

Cati, D.S.¹  Stoeckli-Evans, H.² 

[1] Debiopharm International S.A., Chemin Messidor 5-7, CP 5911, CH-1002 Lausanne, Switzerland;Institute of Physics, University of Neuchâtel, rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland

关键词: CRYSTAL STRUCTURE;    CARBOXAMIDE;    PYRAZINE;    PYRIDINE;    SILVER(I);    AG-AG BOND;    THREE-DIMENSIONAL COORDINATION POLYMER;    HYDROGEN BONDING;   

DOI  :  10.1107/S2056989017006387

学科分类：数学（综合）

来源: International Union of Crystallography

【 摘 要 】

The title ligand, C18H16N6O2·2H2O (L1) [N2,N3-bis­(pyridin-4-ylmeth­yl)pyrazine-2,3-dicarboxamide], crystallized as a dihydrate. The mol­ecule is U-shaped with the carboxamide groups being cis to one another, making a dihedral angle of 81.6 (5)°. The terminal pyridine rings are inclined to one another by 58.5 (4)°. There is an intra­molecular N—H⋯Npyrazine hydrogen bond present, forming an S(5) ring motif. In the crystal, adjacent mol­ecules are linked by N—H⋯Ocarboxamide hydrogen bonds, forming a chain along [001]. A chain of hydrogen-bonded water mol­ecules is linked to the chain of (L1) mol­ecules by O—H⋯N hydrogen bonds, forming columns propagating along the c axis. The columns are linked by C—H⋯O and C—H⋯N hydrogen bonds, forming a three-dimensional supra­molecular structure. The reaction of ligand (L1) with silver(I) nitrate led to the formation of a new three-dimensional coordination polymer, {[Ag(C18H16N6O2)]NO3}n, poly[[[μ4-N2,N3-bis­(pyridin-4-ylmeth­yl)pyrazine-2,3-dicarboxamide]­silver(I)] nitrate] (I). The asymmetric unit is composed of half of one silver ion, located on a twofold rotation axis, half a ligand mol­ecule and half a positionally disordered nitrate anion located about a twofold rotation axis. The full mol­ecule of the ligand is generated by twofold rotational symmetry, with this twofold axis bis­ecting the Car—Car bonds of the pyrazine ring and the Ag—Ag bond. The carboxamide groups are now trans to one another, making a dihedral angle of 65.8 (4)°. The two terminal pyridine rings are inclined to one another by 6.6 (3)°. Two ligands wrap around an Ag—Ag bond of 3.1638 (11) Å, forming a figure-of-eight-shaped complex mol­ecule. Each silver ion is coordinated by two pyridine N atoms and by two carboxamide O atoms of neighbouring mol­ecules, hence forming a three-dimensional framework. The nitrate anion is linked to the framework by N—H⋯O and C—H⋯O hydrogen bonds.

【 授权许可】

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