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The results of recent developments in tellurium- and selenium-nitrogen chemistry are presented with emphasis on the preparation, characterization and properties. Wherever possible, the chemistry of cyclic compounds is separated from acyclic species, which are classified according to their oxidation state. Besides conventional methods, e.g. the metathetical reaction between TeX4 (X = F, Cl) or SeX4 (X = Cl) and silylamines such as [R3Si)nNR3-n or R3SiNSNSiR3 etc., two synthons X(NSO)2 (X = Se, Te) that play an important role in Se-N, Te-N and S-N heterocyclic chemistry are described here. For a better understanding, possible reaction pathways for synthesis with Te(NSO)2 or Se(NSO)2 are discussed and evidence for these mechanisms is provided. Attention is also paid to compounds with SeN double bonds. Carbon-, phosphorus- and metal-containing Se-N as well as Te-N heterocycles are dealt with rather restrictively. Vibrational, mass spectroscopic and NMR data are given for important molecules.

The results of recent developments in tellurium- and selenium-nitrogen chemistry are presented with emphasis on the preparation, characterization and properties. Wherever possible, the chemistry of cyclic compounds is separated from acyclic species, which are classified according to their oxidation state. Besides conventional methods, e.g. the metathetical reaction between TeX4 (X = F, Cl) or SeX4 (X = Cl) and silylamines such as [R3Si)nNR3-n or R3SiNSNSiR3 etc., two synthons X(NSO)2 (X = Se, Te) that play an important role in Se-N, Te-N and S-N heterocyclic chemistry are described here. For a better understanding, possible reaction pathways for synthesis with Te(NSO)2 or Se(NSO)2 are discussed and evidence for these mechanisms is provided. Attention is also paid to compounds with SeN double bonds. Carbon-, phosphorus- and metal-containing Se-N as well as Te-N heterocycles are dealt with rather restrictively. Vibrational, mass spectroscopic and NMR data are given for important molecules.

New Routes for the Formation of Te–N Bonds – Synthesis, Structure, and Properties of Cl6Te2N2S Besides Cl2 (1), the reaction of Se(NSO)2 with TeCl4 leads to the formation of [Se2N2S]22+[TeCl5-]2 (2) and the bicyclic heterocycle Cl6Te2N2S (3). The latter is also accessible by treating Se(NSO)2 with TeCl3+AsF6-. Another product of this reaction is the well-known salt [Se2N2S]22+[AsF6-] 2. Treatment of TeCl4 with Me3SiNSO in CH2Cl2 provides 3 on a preparative scale. Its structure has been determined by X-ray crystallography.

Synthesis, Structures, and Properties of Cl2TeSeN2S and [Se2N2S]22+ [XSO3−]2 (X = F, CF3) Treatment of Se(NSO)2 with TeCl4 provides the colvalent five-membered ring species (1). Reaction of Se(NSO)2 with XSO3H (X = F or CF3) leads to bis(1,3,4,2,5-thiadiselenadiazolium) cations with the anions FSO3− (2a) and CF3SO3− (2b). X-ray structure analyses for 1 and 2b are presented.

Synthesis, Structures, and Properties of Cyclothiaselenazenium Cations [[Se2N2S]22+, [XSe2N2S]+, [Se2N2S]2+, [S3SeN5]+as well as Cl2Se2N2S and SeSN2 and SeSN2 ṁ TiCl4 Bis(sulfinylamino)selane (1), prepared from Se2Cl2 and (CH3)3SiNSO, reacts with Lewis acids such as MF5 (M = As, Sb, Nb) and BF3 to form bis(1,3,4,2,5-thiadiselenadiazolium) cations (3) with counter anions AsF-6 (3a), SbF-6 (3b), NbF-6 (3c), BF-4 (3d). Treatment of Se2Cl2 with LiN[Si(CH3)3]2 leads to [(CH3)3Si]2NSexN[Si(CH3)3]2 (x = 1, 2a: 2, 2b). From 2a and 2a and SeCl4 explosive Se4N4 is obtained. Chlorination of 3a and 3c gives [ClSe2N2S]+[MF6]- (M = As, 4a, and Nb, 4c). Analogous bromination of 3a provides [BrSe2N2S]+ [AsF6]- (4b). This type of chlorinated five-membered rings is also obtained directly from 1 and SbCl5 and PCl5 or SeCl4. The products isolated are [ClSe2N2S]+ [SbCl6]- (4d) and [ClSe2N2S]+Cl- (4e). – A covalent species 5, isomeric to 4e, is obtained from 1 and POCl3, and a four-membered ring SeSN2 ṁ TiCl4 (6) from 1 and TiCl4. When 3a or 1 is treated with a two- or threefold excess of AsF5 the stable dication [Se2N2S]2+ (7) is formed. It arises also from 4e and AgAsF6. Attempts to replace TiCl4 in 6 by AsF5 lead to [SeS3N5]+ [AsF6]- (8) with a bicyclic structure for the cation. X-ray structure analyses for 1, 4c, 4d, 4e, 5, and 8 are performed.

The first five-membered chalcogen–nitrogen ring system, containing two Te atoms, Cl2[graphic omitted], has been prepared either by dechlorination of Cl6Te2N2S with Ph3Sb or by reaction of S[N(SiMe3)2]2 with TeCl4; treatment of Cl2[graphic omitted] with AsF5 in liquid SO2 leads to the formation of [Cl[graphic omitted]]+[AsF6]–, and the molecular structure of this salt has been determined by X-ray crystallography.