Boron, not boring

Alexander Boldyrev and colleagues at Utah State University, Logan, working with Lai-Sheng Wang and colleagues at Brown University in Providence, Rhode Island have synthesized a planar boron compound that has the highest coordination number of any flat molecule, squeezing ten spoke-like bonds to boron atoms into a wheel. This astounding feat of engineering not only breaks previous records for such compounds but offers new insights into bonding, coordination and the development of boron chemistry. Theoretical chemist Pekka Pyykkö of the University of Helsinki, Finland, is impressed. "At a deeper, quantum mechanical level, I find the electronic structure entirely logical and a pretty example on the eighteen-electron (18e) rule," he says.