The variations in hydrogen bonding in hexafluorosilicate salts of protonated methyl substituted pyridines and tetramethylethylenediamine

Abstract The synthesis and spectroscopic characterization of hexafluorosilicate salts with organic cations (R) 2 [SiF 6 ] (where R = 2-picolinium ( 1 ), 2,6-lutidinium ( 2 ) and 2,4,6-collidinium ( 3 )) and R[SiF 6 ]·2H 2 O (where R = tetramethylethylenediammonium ( 4 )) are reported. The salts were prepared by the reaction of methyl substituted pyridines or tetramethylethylenediamine with hydrogen fluoride solution and subsequent addition of silica. The crystal structures of 1 , 2 and 4 have been determined by single-crystal X-ray diffraction analysis. The effect of hydrogen bonding on the elongation of the Si F bonds is discussed.