TY - JOUR
T1 - The structure-directing amine changes everything
T2 - Structures and optical properties of two-dimensional thiostannates
AU - Filsø, Mette
AU - Chaaban, Iman
AU - Al Shehabi, Amer
AU - Skibsted, Jørgen
AU - Lock, Nina
PY - 2017
Y1 - 2017
N2 - Two different two-dimensional thiostannates (SnS) were synthesized using tris(2-aminoethyl)amine (tren) or 1-(2-aminoethyl)piperidine (1AEP) as structure-directing agents. Both structures consist of negatively charged thiostannate layers with charge stabilizing cations sandwiched in-between. The fundamental building units are Sn 3 S 4 broken-cube clusters connected by double sulfur bridges to form polymeric (Sn 3 S 7 2-) n honeycomb hexagonal layers. The compounds are members of the R-SnS-1 family of structures, where R indicates the type of cation. Despite consisting of identical structural units, the band gaps of the two semiconducting compounds were found to differ substantially at 2.96 eV (violet-blue light) and 3.21 eV (UV light) for tren-SnS-1 and 1AEP-SnS-1, respectively. Aiming to explain the observed differences in optical properties, the structures of the two thiostannates were investigated in detail based on combined X-ray diffraction, solid-state 13 C and 119 Sn MAS NMR spectroscopy and scanning electron microscopy studies. The compound tren-SnS-1 has a hexagonal structure consisting of planar SnS layers with regular hexagonal pores and disordered cations, whereas 1AEP-SnS-1 has an orthorhombic unit cell with ordered cations, distorted hexagonal pores and non-planar SnS layers. In the formation of 1AEP-SnS-1, an intramolecular reaction of the structure-directing piperidine takes place to form an N-heterobicyclic cation through in situ C-H activation. Hirshfeld surface analysis was used to investigate the interaction between the SnS layers and cations in 1AEP-SnS-1 and revealed that the most nucleophilic part of the SnS sheets is one of the two crystallographically distinct double sulfur bridges.
AB - Two different two-dimensional thiostannates (SnS) were synthesized using tris(2-aminoethyl)amine (tren) or 1-(2-aminoethyl)piperidine (1AEP) as structure-directing agents. Both structures consist of negatively charged thiostannate layers with charge stabilizing cations sandwiched in-between. The fundamental building units are Sn 3 S 4 broken-cube clusters connected by double sulfur bridges to form polymeric (Sn 3 S 7 2-) n honeycomb hexagonal layers. The compounds are members of the R-SnS-1 family of structures, where R indicates the type of cation. Despite consisting of identical structural units, the band gaps of the two semiconducting compounds were found to differ substantially at 2.96 eV (violet-blue light) and 3.21 eV (UV light) for tren-SnS-1 and 1AEP-SnS-1, respectively. Aiming to explain the observed differences in optical properties, the structures of the two thiostannates were investigated in detail based on combined X-ray diffraction, solid-state 13 C and 119 Sn MAS NMR spectroscopy and scanning electron microscopy studies. The compound tren-SnS-1 has a hexagonal structure consisting of planar SnS layers with regular hexagonal pores and disordered cations, whereas 1AEP-SnS-1 has an orthorhombic unit cell with ordered cations, distorted hexagonal pores and non-planar SnS layers. In the formation of 1AEP-SnS-1, an intramolecular reaction of the structure-directing piperidine takes place to form an N-heterobicyclic cation through in situ C-H activation. Hirshfeld surface analysis was used to investigate the interaction between the SnS layers and cations in 1AEP-SnS-1 and revealed that the most nucleophilic part of the SnS sheets is one of the two crystallographically distinct double sulfur bridges.
KW - Hirshfeld surface analysis
KW - light absorption
KW - single-crystal diffraction
KW - solid-state NMR spectroscopy
KW - solvothermal synthesis
KW - two-dimensional thiostannates
UR - http://www.scopus.com/inward/record.url?scp=85031310452&partnerID=8YFLogxK
U2 - 10.1107/S2052520617010630
DO - 10.1107/S2052520617010630
M3 - Journal article
C2 - 28980999
AN - SCOPUS:85031310452
SN - 2052-5206
VL - 73
SP - 931
EP - 940
JO - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
JF - Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
ER -