Structure-bandgap tunability of metal halide perovskites: Synthesis, spectral, single crystal X-ray structural, BVS, CShM and Hirshfeld surface analysis of piperidinium hexahalostannates(IV)

[NH3(CH2)4NH3]SnX4 (X = Br, I): Dion–Jacobson type 2-D perovskites with short interlayer spacing

“…The Sn–Br bond distances (2.579–2.625 Å) are consistent with those of other hybrid Sn( iv ) bromides. 29,30 The [SnBr 6 ] 2− octahedra are only slightly distorted as we do not expect distortion in Sn( iv ) ions due to the lack of 5s 2 lone pairs. The H atoms of the –NH 3 + terminals form N–H⋯Br hydrogen bonds with the octahedra (the shortest N⋯Br distance of 3.535 Å).…”