Molecular E4 Moieties

Historically, Te4 was the first of the dications to be observed already in 1798 (red solution of Te in concentrated sulfuric add), yet the E4 structure was only assigned in the 1960s. The number of known structures increases with increasing weight of the chalcogen thus, while only two 84 structures  

Solid-state structure with contacts below 350 pm of the cation Te/ Te4[AsFg]2(S02) (see ref 31) 

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