Nonahalogenodiantimon(III)ates; their preparation and the crystal structures of [Hpy]3[Sb2Cl9], [NMe4]3[Sb2Br9], and [NMe4]3[Sb2Br3Cl6]

Structure and phase transitions in [(CH3)4P]3[Sb2Br9] and [(CH3)4P]3[Bi2Br9]

“…This phenomenon is also observed in closely related compounds, e.g. ½ðCH 3 Þ 4 N 3 ½Sb 2 Br 9 [15] and ½ðCH 3 Þ 4 N 3 ½Bi 2 Br 9 [18,19]. It means that the M-X b -M angles (X b -bridging halogen atoms) and M-M distance increase with increasing X -X repulsion (Sb-Sb 3:933Å; Bi-Bi 4:010Å).…”

“…It is caused by the disorder forced on the tetramethylphosphonium cations by the trigonal space group symmetry. We should add that the pure refinements have been obtained previously for a similar type of compounds: ½ðCH 3 Þ 4 N 3 ½Sb 2 Br 9 (the final R ¼ 0:14), ½ðCH 3 Þ 4 N 3 ½Sb 2 Br 3 Cl 6 ðR ¼ 0:115Þ [15], crystallizing in the hexagonal symmetry.…”

“…In the case of tetramethylammonium halogenoantimonates(III) and halogenobismuthates(III) discrete ½M 2 X 9 3À anions appears for bromine or mixed halogen analogs like: ½ðCH 3 Þ 4 N 3 ½Sb 2 Br 9 ; ½ðCH 3 Þ 4 N 3 ½Sb 2 Br 3 Cl 6 [15]. Large organic cations and halogen atoms, and first of all, a lack of specific interactions of tetramethylammonium or tetramethylphosphonium cations with the anions may inhibit the formation of a polymeric anion.…”

Structural characterization, thermal, dielectric and vibrational properties of tris(allylammonium) hexabromoantimonate(III), (C3H5NH3)3SbBr6

“…Numerous structural studies show that these metal(III) halide complexes are characterized by a rich diversity of the anionic forms [4,5]. The anionic substructure, because of its large electric polarizability, was found to play an essential role in the generation of polar properties.…”

Unprecedented solid-state chemical reaction—from . From centrosymmetric to non-centrosymmetric crystal structure

“…Ferroelectric properties have been discovered in numerous halogenoantimonates(III) and halogenobismuthates(III) forming molecular-ionic crystals of the general formula R a M b X 3b + a (where R denotes organic cations, M ¼ Sb, Bi and X ¼ Cl, Br, I) [9][10][11]. A characteristic feature of these molecular-ionic solid complexes is a rich diversity of anionic substructures [12,13]. So far, more than 30 various anionic frameworks have been synthesized.…”