New Thiostannates Synthesized Under Solvothermal Conditions: Crystal Structures of (trenH)₂Sn₃S₇ and {[Mn(tren)]₂Sn₂S₆}

Abstract

The two new thiostannate compounds (trenH) 2 Sn 3 S 7 (1) and {[Mn(tren)] 2 Sn 2 S 6 } (2) (tren = tris-2-aminoethylamine) were obtained under solvothermal conditions. Compound 1 crystallizes in the hexagonal space group P6 3 /mmc with a = 13.2642(19), c = 19.078(3) Å, V = 2906.9(7) Å 3 . The layered [Sn 3 S 7 ] 2− anion is constructed by Sn 3 S 4 semi-cubes sharing common edges. The layers are characterized by large hexagonal pores with dimensions of about 11 × 11 Å 2 . Compound 2 crystallizes in the triclinic space group P1 with lattice parameters a = 7.6485(7), b = 8.1062 (7), c = 12.1805(11) Å, α = 97.367(11), β = 103.995(11), γ = 108.762(10) • , V = 676.17(10) Å 3 . The [Sn 2 S 6 ] 4− anion is composed of two edge-sharing SnS 4 tetrahedra and joins two Mn 2+ -centered complexes by Mn-S bond formation. The Mn 2+ cation is in a trigonal-bipyramidal environment of four N atoms of the tren ligand and one S atom of the thiostannate anion. Both compounds are semiconductors with a band gap of 2.96 eV for 1 and of 2.75 eV for 2.

Light absorption engineering of a hybrid (Sn3S72−)n based semiconductor – from violet to red light absorption

“…3). The pattern for the pristine phase matches the phase reported in the literature33. In addition, an impurity of the SnO 2 precursor is present; the concentration of SnO 2 in a representative Sn 3 S 7 (trenH) 2 sample was estimated to be 8 wt% by Rietveld refinement (Fig.…”

“…It is proposed by Pienack et al . that the molecular cations are present as protonated tren (trenH + ) in agreement with elemental analysis33. In the synthesis of other R-SnS-1 type materials, however, it was reported that the synthesis template may undergo intramolecular structural changes during the solvothermal reaction34.…”

“…The molecular cations are statically disordered in the crystal structure of Sn 3 S 7 (trenH) 2 33, and the nature of the embedded cationic species has not been verified in previous studies. It is proposed by Pienack et al .…”

“…1). The thiostannate layers in Sn 3 S 7 (trenH) 2 may be described in the hexagonal space group P6 3 / mmc with unit cell dimensions of a  = 13.3 Å and c  = 19.1 Å33. The thiostannate layers stack in an ABAB sequence along the c -axis.…”

“…In order to investigate the effect on the unit cell of the ion exchange, powder diffraction data were modelled by Le Bail fitting using the unit cell of pristine Sn 3 S 7 (trenH) 2 as starting model33. The unit cell c -axis decreases with the dye content, revealing that the distance between the thiostannate layers decreases upon dye exchange (Table 1 and Fig.…”