What is "trisborane"

Tris(pentafluorophenyl)borane, sometimes referred to as "BCF", is the chemical compound (CF)B. It is a white, volatile solid. The molecule consists of three pentafluorophenyl groups attached in a "paddle-wheel" manner to a central boron atom; the BC core is planar. It has been described as the “ideal Lewis acid” because of its versatility and the relative inertness of the B-C bonds. Related fluoro-substituted boron compounds, such as those containing B-CF groups, decompose with formation of B-F bonds.