Reactivity of a Distannylene toward Potassium Graphite: Synthesis of a Stannylidenide Anion

The synthesis and characterization of the stannylidenide anion [LSn:]− (L = 2,6-(CHNBut)2C6H3) supported by the 2,6-diiminophenyl ligand is described. The reaction of the chlorostannylene [LSnCl] (2) with excess KC8 in diethyl ether at room temperature afforded the distannylene [LSn:]2 (3). The treatment of 3 with 2 equiv of KC8 in tetrahydrofuran (THF) resulted in the cleavage of the SnI–SnI bond in 3 to afford the potassium stannylidenide [LSnK·THF] (4). The molecular structure of compound 4 as determined by single-crystal X-ray diffraction analysis shows that the K atom is η5-coordinated to the low-valent tin heterocycle. Moreover, the negative charge at the Sn atom in compound 4 is stabilized by an electron delocalization in the low-valent tin heterocycle.