Synthesis and Structural Study of Some Pyrimidinium Hexafluoridosilicates.

The synthesis and spectroscopic characterization of some pyrimidinium hexafluoridosilicate salts with the formula (RH)2[SiF]6 (where R = 2-aminopyrimidine (1), cytosine (2) and 5-cyanocytosine (3)) is obtained in the reaction of SiO2 with hydrofluoric acid solution and subsequent addition of 2-aminopyrimidine, cytosine or 4-amino-2-chloropyrimidine-5-carbonitrile. The crystal structures of 1 and 3 have been determined by single-crystal X‒ray diffraction analysis. The combination of N‒H···F hydrogen bonds along with π‒π interactions between aromatic rings resulted in supramolecular architecture of cations and anions in the solid state.