Mixed Pentele-Chalcogen Cationic Chains from Aluminum and Gallium Halide Melts

Abstract

The reactions of tellurium or selenium with bismuth or antimony in chloridogallate and iodidoaluminate melts in the presence of group 15 trihalides as weak oxidants yielded the compounds (Sb2Te2)[GaCl4] (1), (Sb2Te2)I[AlI4] (2), (Bi2Te2)Cl[GaCl4] (3a), (Bi2Se2)Cl[GaCl4] (3b), (Sb3Te4)[GaCl4] (4), and (SbTe4)[Ga2Cl7] (5). In the crystal structures one-dimensional polymeric cations (Sb2Te2(+))n (1), (Sb2Te2(2+))n (2), (Bi2Te2(2+))n (3a), (Bi2Se2(2+))n (3b), (Sb3Te4(+))n (4), and (SbTe4(+))n (5) are present. The polymeric cationic strands in 2, 3a, 3b, and 4 consist of pentele/chalcogen dumbbells, which are connected to ladder-shaped bands. The strands in 1 and 5 consist of condensed rings that involve four-membered Sb2Te2 rings for 1, and five-membered SbTe4 rings for 5. The counteranions are the weakly coordinating [GaCl4](-), [AlI4](-), and [Ga2Cl7](-) in addition to Cl(-) and I(-) anions, which are coordinated to the atoms of the cations. The crystal structures of 1-4 are characterized by a statistical disorder in the anions with alternatively occupied positions for the Al and Ga atoms. For 4 superstructure reflections appear in the diffractions patterns, indicating a partial order. A correct assignment of the Sb and Te positions in the cation of 5 was achieved by periodic quantum-chemical calculations, which were performed via a Hartree-Fock density functional theory hybrid method. A clear preference of the 4-fold coordinated site was obtained for Sb.

Se4CuX, Te4CuX and Cu2Se7X2 (X=GaCl4) — Coordination compounds of neutral infinite chalcogen chains

“…CuCl and CuCl 2 were added to take the role of adjuvants without being incorporated in the final products as already observed for several cases [15][16][17]. The formation of (Sb 2 Te 4 )[GaCl 4 ] 2 [18] with a prism shaped (Sb 2 Te 4 ) 2+ cluster as the second product in similar yield in the reaction leading to 2 proves this approach.…”

β‐[SbI2][AlI4] – A Second Polymorph of Diiodidoantimony‐Tetraiodido Aluminate with a Polymeric Structure

“…β‐[SbI 2 ][AlI 4 ] ( 1 ) was first observed as a byproduct in the syntheses of (Sb 2 Te 2 )I[AlI 4 ] . Phase pure 1 is obtained by reacting a 1:1 mixture of SbI 3 and AlI 3 at 190 °C.…”

“…Al was described with the all‐electron basis set 86–21G* . The Hartree‐Fock density functional theory hybrid method PW1PW was applied as in our previous study of (SbTe 4 + ) n clusters . Integral accuracy parameters were set to strict values (10 –9 for Coulomb integrals and 10 –18 for Exchange compared to the default values 10 –7 and 10 –14 , respectively).…”