Room-Temperature Synthesis of [BMIm][Sn5O2Cl7] with infinity(1) (Sn2OCl2) Strands in a Saline [BMIm][SnCl3] Matrix

The novel tin(II) oxychloride [BMIm][Sn5O2Cl7] (BMIm = 1-butyl-3-methylimidazolium) is obtained by the room-temperature reaction (25 degrees C) of black SnO and SnCl2 in [BMIm]Cl/SnCl2 as an ionic liquid. The title compound can be described as composed of noncharged, infinite infinity(1)(Sn2OCl2) strands that are embedded in a saline matrix of [BMIm](+) and [SnCl3](-). The infinity(1)(Sn2OCl2) strands consist of a backbone of edge-sharing OSn4/2 tetrahedra, which represent one-dimensional (1D) strands cut out of the layer-type structure of SnO. In [BMIm][Sn5O2Cl7], the infinity(1)(Sn2OCl2) strands, which mimic a 1D semiconductor, are terminated by chlorine atoms, whereas they are interconnected by oxygen atoms in the 2D semiconductor SnO. The view of the noncharged infinity(1)(Sn2OCl2) strands in a saline [BMIm][SnCl3] matrix is validated by dissolution experiments. Thus, electron microscopy and Raman spectroscopy show a deconstruction of [BMIm][Sn5O2Cl7] single crystals after treatment with chloroform with a dissolution of [BMIm][SnCl3], the formation of SnCl2 needles, and tin oxide as a solid remain.