Cyanoscorpionate Ligands: Agostic Interactions in a Series of Metal Complexes Containing the Tris(4‐cyano‐3‐phenylpyrazolyl)borate and Bis(4‐cyano‐3‐phenylpyrazolyl)borate Ligands

Scorpionate chemistry has long featured sandwich complexes with two trispyrazolylborate (Tp) or two bispyrazolylborate (Bp) ligands coordinated to a transition metal. Less common are complexes in which one Tp and one Bp ligand are coordinated to the metal. We report herein five such complexes of Ni II , Mn II , Co II , or Fe II involving Tp and Bp ligands comprising either 3‐phenyl‐4‐cyanopyrazole or 3‐phenylpyrazole, as well as a related Co II complex with two Tp ligands, one of which is coordinated in a κ 2 fashion. All complexes feature an agostic interaction with a B–H hydrogen atom.