[Te₈][NbOCl₄]₂containing an infinite chain-like {[Te–Te–Te–(Te₅)]²⁺}_npolycation

Abstract

The title compound, [Te(8)][NbOCl(4)](2), was obtained as translucent black crystals by reaction of elemental tellurium, niobium(V) chloride and niobium(V) oxychloride in the ionic liquid BMImCl (BMImCl is 1-butyl-3-methylimidazolium chloride). The synthesis was performed in argon-filled glass ampoules. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and consists of infinite {[Te(8)](2+)}(n) cations associated with pyramidal [NbOCl(4)](-) anions. The novel catena-octatellurium(2+) cation is composed of Te(5) rings that are linked via Te(3) units [Te-Te = 2.6455 (18)-2.8164 (19) Å]. The composition and purity of [Te(8)][NbOCl(4)](2) were further confirmed by energy-dispersive X-ray diffraction (EDX) analysis.

The 1D‐Polymeric (Te72+)n in (Te7)[MF6]2 (M=As, Sb, Nb, Ta) by Solvothermal, Microwave Assisted, and Electrochemical Synthesis

“…On the other hand, polymeric tellurium cations with bonds in the single bond range along the chain are numerous for tellurium and occur as different isomers of the polymeric heptatellurium(2+) in (Te 7 )[MOX 4 ]X (M=Nb, W; X=Cl, Br), [2] and in (Te 7 )[Be 2 Cl 6 ] [3] . Other polymeric tellurium cations like (Te 4 2+ ) n , (Te 6 2+ ) n , (Te 8 2+ ) n and (Te 10 2+ ) n have been obtained as (Te 4 )(Te 10 )[Bi 4 Cl 16 ], [3] (Te 6 )[MCl 6 ] with M=Zr, Hf, [4] (Te 8 )[U 2 Br 10 ], [5] (Te 8 )[Bi 4 Cl 14 ], [6] (Te 8 ) 2 [Ta 4 O 4 Cl 16 ] [7] and (Te 8 )[NbOCl 4 ] 2 [8] …”

“…) n have been obtained as (Te 4 )(Te 10 )[Bi 4 Cl 16 ], [3] (Te 6 )[MCl 6 ] with M = Zr, Hf, [4] (Te 8 )[U 2 Br 10 ], [5] (Te 8 )[Bi 4 Cl 14 ], [6] (Te 8 ) 2 [Ta 4 O 4 Cl 16 ] [7] and (Te 8 )[NbOCl 4 ] 2 . [8] Chalcogen polycations can be prepared by different methods: 1) in Lewis acidic melts like AlCl 3 /NaAlCl 4 , [9] 2) in solution, preferably in liquid SO 2 as solvent [10] or super acidic solution e. g. HF/AsF 5 , [11] 3) by gas phase deposition in chemical vapor transport reactions using volatile metal halides as oxidants towards the elemental chalcogens, 4) in ionic liquids, which, due to the low reactions temperatures, expanded the synthetic possibilities essentially. [12] Starting from elemental chalcogens, oxidation is necessary and in general by all routes, ionic compounds are obtained, whose anions, mostly halogenido metalates as weak conjugate bases of strong Lewis acidic metal halides, stabilize the "naked" polycationic clusters.…”

The Mixed‐Valence Catena‐Heteropolycation (Bi2S2)+

“…[25] Catena-polycations of group 16 elements have first been observed as parts of the subhalides Te 3 Cl 2 and Te 2 X (X = Cl, Br) by Kniep et al [32] Subsequently, Beck et al significantly expanded this compound class. [33][34][35][36][37][38][39][40][41] The chemical bonding in those chalcogen polycations is typically based on two-center two-electron (2c2e) bonds. Consequently, their structures combine the two-and three-fold connectivity of Ch atoms and Ch + cations, following the octet rule.…”

“…Subsequently, Beck et al. significantly expanded this compound class [33–41] . The chemical bonding in those chalcogen polycations is typically based on two‐center two‐electron (2c2e) bonds.…”

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

“…For example, (Te 7 2+ ) n exists in two modifications, as a folded band in Te 7 [WOX 4 ] 2 (X = Cl, Br) and Te 7 [Be 2 Cl 6 ] and as strands of connected six-membered rings in Te 7 [AsF 6 ] 2. The cationic tellurium strand (Te 8 2+ ) n occurs as two differently folded chains of connected six-membered rings in Te 8 [Bi 4 Cl 14 ], Te 8 [U 2 Br 10 ], and Te 8 [NbOCl 4 ] 2 . A combination of two different polymeric tellurium strands is present in (Te 4 )(Te 10 )­[Bi 4 Cl 16 ] .…”