Cyclic tellurium imides

The discovery of cyclic imides of the heavier chalcogens is a relatively recent development. The ring systems that have been structurally characterized all have bulky substituents attached to the nitrogen atoms, viz., Se3(NR)2 (74, R= Bu, Ad),30,152 Se3(N Bu)3 (75),160 Se Bu (76)208 and Se9(N Bu)6 (77).208 The only known cyclic tellurium imide is Te3(NtBu)3.150... 

The corresponding tellurium diimide BuNTe( -N Bu)2TeN Bu (10.7) may be obtained in good yields from the reaction of lithium tert-butylamide with TeCU in THE (Eq. 10.3). °" In toluene solution this reaction also produces the cyclic tellurium(II) imide (TcN Bu)3. The dimer 10.7 is obtained as an orange solid, which can be purified by vacuum sublimation at ca. 90°C. 

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