Planar Four-Coordinate Boron: A Single, Flat Boron Atom as a Ligand for Four Metals


  • Financial support from the European Research Council (Advanced Investigator Grant to H.B.) is gratefully acknowledged.


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You may now kiss the boride: Four-coordinate boron, carbon, and nitrogen are almost always tetrahedral. The first examples of compounds with near-planar four-coordinate boron atoms have been prepared from trinuclear coordinatively unsaturated borido complexes. The two resultant tetranuclear complexes (see scheme) both feature near-planar four-coordinate boron atoms, with angle sums of 362.4° and 364.6°.