First reductive dimerization of a polycyclic azine

The tptz molecule is reduced by potassium into its anion-radical in the compound K(tptz)2 (1), whereas it is reductively coupled by SmI2 and UI3(py)4 into the bis-triazinide ligand in the dinuclear complexes [Sm2(tptz–tptz)(DMF)8][I]4·3.5DMF (2·3.5DMF) and U2I6(tptz–tptz)(MeCN)2·2MeCN (3·2MeCN) where each metal ion occupies a pentadentate N5 cavity of the [tptz–tptz]2– ligand.