Pseudohalogen compounds of astatine: Synthesis and characterization of At/I/-tricyanomethanide-and At/I/-azide-compounds

Reactions of At//⁺, At^o.H₂O, AtCl ₂ ^– and AtBr₂ with the pseudohalogenides tricyanomethanide and azide are described. Information on the compound formation of astatine with C/CN/ ₃ ^– and N ₃ ^– could be obtained on the basis of electromigration investigations under variation of the conditions /composition of the electrolyte, pH, exchange reactions of ligands/. For the reaction: At/H₂O/C/CN/₃]+C/CN/ ₃ ^– At/C/CN/₃/₂]+H₂O at 301 K and u=0.075 mol.l^–1 K₂=/675±25/ 1.mol^–1] and u^o=–/3.50±0.10/×10^–4 cm².s^–1.V^–1]. According to this astatine/I/-tricyanomethanide is classified between AtI ₂ ^– and At/SCN/ ₂ ^– . First investigations in azid-containing systems confirm the formation of astatine/I/-azide-compounds. Their composition is probably At/N₃/ ₂ ^– . There is no dependence of the ion mobility of astatine/I/-azide in the investigated range on azide concentration which is due to its high stability.