Bis(triethylammonium) hexachlorostannate (IV): crystal structure and hydrogen bonding

Abstract

The crystal structure of (Et3NH)2SnCl6 at room temperature consists of a monoclinically distorted antifluorite packing of Et3NH+ and SnCl62− ions. Each anion has two cations centrosymmetrically associated with it through bifurcated hydrogen bonds to four of the Cl atoms, leaving two of the six chlorines unengaged. The bifurcation is nearly symmetric and the [Formula: see text] group is nearly planar. Infrared spectra of undeuterated and partially deuterated polycrystalline (Et3NH)2SnCl6 show that the NH stretching vibration is essentially uncoupled while the corresponding ND vibration undergoes a complex Fermi resonance resulting in a multiplet in the spectrum of even weakly deuterated material. The hydrogen bonding in (Et3NH)2SnCl6 is stronger than in the corresponding ammonium compound. A negative temperature coefficient of the NH and ND stretching frequencies is consistent with the bifurcation of the hydrogen bond. If a low-temperature transition exists, it was not evident in the NH and ND stretching absorptions.