Hexafluorosilicates with heterocyclic cations are convenient models for the estimation of H-bonds influence on structural characteristics and properties of this onium salts. As a part of our systematic investigation here we describe results of X-ray structure analysis and solubility data determination of the hexafluorosilicates (4,4´-DipyH2)SiF6 (I) and (2-Br-6- CH3C5H3NH)2SiF6·H2O (II). Colourless crystals of the compounds I and II were separated as products of the interaction of hexafluorosilicic acid with corresponding amine. Crystal structures of I and II (a, c) and fragments of crystal packing in I and II (b, d) are presented below.figureBoth structures are built from the H-bonded units consisting of the SiF6 2– anion and cations. Structure II also includes the water molecule. Complex I represents example of the structure in the form of 1D chain, in which 4,4´-DipyH2 2+ cations and SiF6 2– anions joined through strong N(1)H···F(3) bonds (N···F 2.694(2) Å). In the SiF6 2– anion the SiF bond lengths are between 1.6749(11) and 1.7054(10) Å. The fluorine atoms in the longer Si(1)F(3) bond participates in the H-bond. The crystal structure II is stabilized by the network of H-bonding O(1W)H···F(1) (O···F 2.805(8) Å), O(1W)H···Br(1) (O···Br 3.00(4) Å), O(1W)H···F(3) (O···F 2.779(7) Å), N(1)H···O(1W) (N···O 2.709(9) Å). The solubility data of I, II and (2,2´-DipyH2)SiF6 (III) in water (mol. %, 25 °C): 0,36, 2,01, 10,58. Some relationship between solubility data and interionic H-bonds characteristics of onium hexafluorosilicates will be discussed.