AbstractTreatment of Se(NSO)2with TeF4in CH2Cl2yields the compounds (4a) and (5b), while with TeBr4after six months (2d) is formed. An almost quantitative yield of Cl4Te2N4S2(6) is obtained from either Cl6Te2N2S (1a) and (CH3)3SiNSNSi(CH3)3in CH2Cl2at 20°C (2 d) or TeCl4and (CH3)3SiNSO (molar ratio 1:2) in CH2Cl2at 60°C (3 d). The use of (CH3)3SiOSi(CH3)3as solvent in the last mentioned procedure gives1aand small amounts of Cl2Te(NSO)2. Similarly, F2Te(NSO)2is prepared from TeF4and (CH3)3SiNSO in CH2Cl2. Dechlorination of1awith (C6H5)3Sb leads to (2a), which is also produced from TeCl4and [(CH3)3Si]2NSN[Si(CH3)3]2. When TeF4is used instead of TeCl4(molar ratio 3:1) the salt (7a) is formed. Similarly, (7b) is prepared from2aand AsF5or Ag+[AsF−6] in SO2. A new method for the preparation of bicyclic type1telluraheterocycles involves bromination of2ayielding Cl2Br4Te2N2S (1b). Dehalogenation with (C6H5)3Sb converts1binto (2b). When2bis treated with Br2in CH2Cl2an oxidative halogenation takes place with formation of Br6Te2N2S (1c). Metathetical exchange between2band Ag+[AsF−6] gives (7c). Isostructural S(NSO)2reacts with TeCl4for several weeks at 60°C in CH2Cl2to form S4N4. TeCl4and [S5N+5][Te3Cl−3], in contrast to the corresponding reaction with Se(NSO)2. The molecular structures of4a, 7b, 8, and [S5N+5][Te3Cl−13] have been determined by X‐ray diffraction methods. Spectroscopic data for all new compounds a