Acyclic and heterocyclic tellurathianitrogen compounds: a review on recent publications

Intensive and broad studies of chemical reactions concerning X(NSO)2 (X=Se, Te), X2Te(NSO)2 (X=F, Cl, Br) and X′2Te(NSC)2X′2 (X′=F, Cl) provides besides new interesting compounds also valuable intermediates for a better understanding of reaction pathways in chalcogen–nitrogen chemistry. Based on the mechanism elucidated for the formation of [+]2[MF6−]2 or [Cl][SbCl6−] from Se(NSO)2 and MF5 (M=As, Sb, Nb) or Se(NSO)2 and SbCl5 respectively an interpretation of the reaction sequences of other procedure such as Te(NSO)2+SbCl5 or e.g. Cl2Te(NSO)2 with MCl3 (M=Ga, Al, Fe) could be provided. It was proved that a desulfurisation process is responsible for transforming Cl2Te(NSO)2 and derivated products in the presence of MCl3 into [(Cl2Te)2N+][MCl4−] and [Cl+][MCl4−]. The results gained in these studies led directly to the synthesis of [+][TeCl5−], the first ring with three cummulated nitrogen atoms. In order to learn more about the possible structures of Cl2Te(NSN)2TeCl2, careful and intensive investigations proved the formation of the cage N[Te(Cl)NSN]3. A thorough reinvestigation of the original synthesis of the cage yielded S4N4 as an additional product and by varying the stoichiometry between the educts TeCl4 and (CH3)3SiNSNSi(CH3)3 important intermediates could be detected and isolated. They provided the base for understanding the consecutive steps during the procedure between educts and to yield products. Fluorine substituted acyclic, cyclic, neutral and ionic chalcogen–nitrogen compounds are described as well as relationship among themselves and related compounds. Interesting and valuable correlations are presented and evaluated.