Synthesis, X-ray structure and topology (AIM and Hirshfeld) analyses of the new square planar [Ag(pyridine-2-aldoxime)2]ClO4 complex. A comparative study with its nitrato analogue

The new homoleptic square planar complex [AgL2]ClO4·H2O; 1, where L is pyridine-2-aldoxime, is synthesized and characterized using elemental analysis, FTIR and NMR spectra as well as X-ray single crystal structure analysis. The ligand (L) acts as a bidentate ligand via the pyridine and oxime N-atoms while the perchlorate anion is not coordinated to the silver atom. The crystal structure of 1 is characterized by one-dimensional infinite hydrogen bond network with backbone build up by hydrogen bridge interactions between the water molecules, the OH groups of the aldoxime and the perchlorate anions. The structure of 1 is optimized using eight DFT methods. The B97D/def2-TZVP and PBEPBE/def2-TZVP are the best to predict the Agsingle bondN/Agsingle bondO distances and the coordination geometry around Ag(I) ion, respectively. Atoms in molecules (AIM) and Hirshfeld topology analyses were used to describe the Agsingle bondN/Agsingle bondO bonding nature and the possible intermolecular interactions, respectively, in comparison with the nitrato analogue [AgL(NO3)]; 2. The O⋯H, H⋯H, C⋯C and H⋯C are the most common intermolecular interactions occurred in both complexes. Only complex 2 showed significant Ag⋯O (2.720–2.731 Å) intermolecular interactions. AIM and NBO analyses explained that the ClO4− anion is weakly interacting with Ag(I) in 1 while the NO3− is coordinated via one of its O-atoms in 2.