Crystal structure and Hirshfeld surface analysis of bis-[hydrazinium(1+)] hexa-fluorido-silicate: (N2H5)2SiF6.

In the title inorganic mol-ecular salt, (N2H5)2SiF6, the silicon atom at the centre of the slightly distorted SiF6 octa-hedron [range of Si-F distances = 1.6777 (4)-1.7101 (4) Å] lies on a crystallographic inversion centre. In the crystal, the ions are connected by N-H⋯N and N-H⋯F hydrogen bonds; the former link the cations into [010] chains and the latter (some of which are bifurcated or trifurcated) link the ions into a three-dimensional network. The two-dimensional fingerprint plots show that F⋯H/H⋯F inter-actions dominate the Hirshfeld surface (75.5%) followed by H⋯H (13.6%) and N⋯H/H⋯N (8.4%) whereas F⋯F (1.9%) and F⋯N/N⋯F (0.6%) have negligible percentages. The title compound is isostructural with its germanium-containing analogue.

Butane-1,4-di-ammonium hexa-fluoro-silicate.

The title compound, [NH3(CH2)4NH3](2+)·SiF6 (2-), is a hybrid built from an organic butane-1,4-di-ammonium dication linked to a hexa-fluoro-silicate mineral anion. Both ions posses inversion symmetry. In the anion the Si atom is located on an inversion center, while in the cation the center of inversion is situated at the mid-point of the central -CH2-CH2- bond. The Si atom is surrounded by six F atoms, forming a slightly distorted SiF6 (2-) octa-hedron. These octa-hedra are linked to the organic cations through N-H⋯F hydrogen bonds, forming a three-dimensional network.

Hexane-1,6-di-ammonium hexa-fluoro-silicate.

The asymmetric unit of the title organic-inorganic molecular salt, C6H18N2 (2+)·SiF6 (2-), consists of one anion and one cation together with half of each of two cations and two anions located on inversion centres. The SiF6 (2-) octa-hedral anions are arranged to form sheets parallel to (011), which are linked into a three-dimensional network by the organic cations through N-H⋯F hydrogen bonds.

catena-Poly[heptyl-enedi-ammonium [[tetra-chloridobismuthate(III)]-µ-chlorido]].

The title organic-inorganic hybrid compound, {(C7H20N2)[BiCl5]} n , consists of distorted corner-joined [BiCl6] octa-hedra forming zigzag polymeric anionic chains parallel to [001], separated by columns of heptyl-enedi-ammonium cations. The asymmetric unit contains two crystallographically independent bis-muth metal atoms, one of which lies on an inversion centre and the other on a twofold axis. In the crystal, the polymeric chains and cations are linked by N-H⋯Cl hydrogen bonds, forming undulating layers parallel to (110).

The infrared and Raman spectra of ethylammonium hexafluorosilicate [C2H5NH3]2SiF6.

The X-rays powder diffraction pattern of [C2H5NH3]2SiF6 was obtained and indexed on the basis of a hexagonal unit cell. The vibrational spectra (IR and Raman) of this compound were recorded and discussed in relation to the above-mentioned crystal structure. The vibrational spectra of the cations indicate that they are disordered and hydrogen bonded to the anions. On the opposite, the Raman spectrum of the anions could be interpreted in terms of ordered groups. The combination bands observed in the 2300-1800 cm(-1) spectral region in the IR spectrum indicate that this compound may contain C-NH3 groups.

Structure and vibrational study of the trimethylammonium hexafluorosilicate [(CH3)3NH]2SiF6 compound.

The X-ray powder diffraction pattern of [(CH(3))(3)NH](2)SiF(6) was obtained and indexed on the basis of a centred cubic unit cell with the P4(1)32 as the likely space group. The Infrared and Raman spectra of this compound have been recorded at room temperature and discussed in relation to the crystal structure. In this salt, the bands corresponding to the cation vibrational modes show that the symmetry of these cations is distorted from the free C(3v) one and that they are strongly hydrogen-bonded to the respective anions. However, the spectra of the anions can be interpreted in term of ordered groups as indicated by the splitting of the bands corresponding to some degenerate vibrational modes. The harmonic frequencies, corresponding to the (CH(3))(3)NH-SiF(6)-NH(CH(3))(3) optimised geometry, were calculated using the SCF semi-empirical MNDO-PM3 method.