Unexpected formation of zinc bis[1,3-di(2-pyridyl)-2-azapropenide] during the thermolysis of methylzinc bis(2-pyridylmemyl)amide

The thermolysis of methylzinc bis(2-pyridylmethyl)amide (1) leads to the formation of gold-shining zinc bis[1,3-di(2-pyridyl)-2-azapropenide] (2) and colorless 1,2-di(2-pyridyl)ethane (3). The 1,3-di(2-pyridyl)-2-azapropenide ligand which forms from the bis(2-pyridylmethyl)amide anion by dehydrogenation shows a delocalization of the anionic charge within the whole substituent. This fact leads to C–C and C–N bond lengths as well as chemical shifts characteristic for aromatic systems.