Paroxetine and Fluoxetine Hexafluorosilicate salts: Synthesis, crystal structure, Hirshfeld surface, and supramolecular analysis

Hexafluorosilicate salts of the antidepressant drugs Paroxetine (PRX) and Fluoxetine (FLX), [PRX](2)SiF6 and [FLX](2)SiF6 center dot H2O, are investigated herein by SCXRD, Hirshfeld surface analysis, and Infrared spectroscopy. By their crystal structures, it is possible to observe, for the first time, at least at the best of our knowledge, the formation of a supramolecular architecture of the (SiF6](2-) anion with protonated secondary amine groups. The [PRX](2)SiF6 crystallizes in the P2(1) space group and the [FLX](2)SiF6 center dot H2O in the P2(1)/c, as a hydrate racemate. While two conformers are present in the asymmetric unit of [PRX](2)SiF6, two enantiomers enclose the one of [FLX](2)SiF6 center dot H2O. Analysis of the crystal packing show that N-HF-Si (1.94-2.42 angstrom), C-HF-Si (2.36-2.62 angstrom), and C-Ha interactions are the main contributors toward the supramolecular architectures in these salts.