Crystal structure of bis­{2-[5-(3,4,5-tri­meth­oxyphenyl)-4H-1,2,4-triazol-3-yl]pyridine}palladium(II) bis­(tri­fluoro­acetate) tri­fluoro­acetic acid disolvate

In the Pd^II complex, two substituted 3-(pyridin-2-yl)-1,2,4-triazole ligands in the neutral form coordinate to the metal atom through the pyridine-N and triazole-N atoms in a trans-configuration.

The new palladium(II) complex, [Pd(C₁₆H₁₆N₄O₃)₂](CF₃COO)₂·2CF₃COOH, crystallizes in the triclinic space group P

with the asymmetric unit containing half the cation (Pd^II site symmetry C i ), one tri­fluoro­actetate anion and one co-crystallized tri­fluoro­acetic acid mol­ecule. Two neutral chelating 2-[5-(3,4,5-tri­meth­oxy­phen­yl)-4H-1,2,4-triazol-3-yl]pyridine ligands coordinate to the Pd^II ion through the triazole-N and pyridine-N atoms in a distorted trans-PdN₄ square-planar configuration [Pd—N 1.991 (2), 2.037 (2) Å; cis N—Pd—N 79.65 (8), 100.35 (8)°]. The complex cation is quite planar, except for the methoxo groups (δ = 0.117 Å for one of the C atoms). The planar configuration is supported by two intra­molecular C—H⋯N hydrogen bonds. In the crystal, the π–π-stacked cations are arranged in sheets parallel to the ab plane that are flanked on both sides by the tri­fluoro­acetic acid–tri­fluoro­acetate anion pairs. Apart from classical N/O—H⋯O hydrogen-bonding inter­actions, weak C—H⋯F/N/O contacts consolidate the three-dimensional architecture. Both tri­fluoro­acetic moieties were found to be disordered over two resolvable positions with a refined occupancy ratio of 0.587 (1):0.413 (17) and 0.530 (6):0.470 (6) for the protonated and deprotonated forms, respectively.