Synthesis of a Carbodicyclopropenylidene: A Carbodicarbene based Solely on Carbon.

The first carbodicarbene stabilized by flanking cyclopropenylidenes is reported. Tetraphenylcarbodicyclopropenylidene (2) is accessed by deprotonation of the corresponding triafulvene cyclopropenium salt, and has been spectroscopically characterized in [D8 ]THF solution at -60 °C. Main-group and transition-metal complexes of 2 have been accessed, and have revealed the high sigma donating ability, and exclusive η(1) binding of this neutral all carbon ligand. Variable temperature NMR spectroscopy studies reveal varying degrees of free rotation in the flanking cyclopropenylidene groups of 2 in its coordination compounds.