Two novel selenidostannates from mixed structure-directing systems: the large ten-membered ring of [Sn3Se4] semicubes and the 3D [Sn4Se9]n2n− with multi-channels

Ionothermal syntheses, characterization and properties of two selenidostannate compounds with two- or three-dimensional (D) skeletons by utilizing the synergistic structure-directing effects of the ionic liquid (IL) [Bmmim]Cl (Bmmim = 1-butyl-2,3-dimethylimidazolium) and in-situ generated metal–amine complexes (MACs), namely, 2D-(Bmmim)2[Ni(teta)(en)][Sn3Se7]2 (1, teta = triethylenetetramine, en = ethylenediamine) and 3D-(Bmmim)1.5(dienH)0.5Ni(dien)2[Sn4Se9]2 (2, dien = diethylenetriamine) are presented. Single-crystal X-ray diffraction analyses revealed that compound 1 possesses a lamellar anionic [Sn3Se7]n2n− structure comprising a large ten-membered ring with a window size of 24.85 × 13.38 Å when considering the [Sn3Se4] semicube as a member. While 2 features a 3D [Sn4Se9]n2n− framework with orthogonally intersecting channels where the three different types of cations are filled. The successful isolation of these two compounds demonstrated again that the mixed SDA strategy is promising for the synthesis of novel crystalline selenidostannates.