Oxoborane

In chemistry, an oxoborane is any chemical compound containing a boron atom with a terminal oxygen atom (a −B=O functional group). The compound class is of some relevance to academic research. The parent compound, HBO, itself called "oxoborane", together with derivatives F B O , ClBO, BrBO, HOBO and MeBO have been detected in matrix isolation or in the gaseous phase at high temperature. ^{[1] [2]} In these compounds the boron and oxygen form a triple bond prone to cyclotrimerization to boroxines.

Derivatives

Although monomeric oxoboranes have not been isolated, derivatives have been described.

A Lewis acid-stabilized adduct of an oxoborane is (NacNacB=O^.AlCl₃. ^[3] In this compound the oxygen atom is coordinated to aluminium chloride. The BO bond length is 130 pm (compare to 136 pm in regular boronic acids). Related systems are known. ^[4]

In trans-[(Cy₃P)₂PtBr(BO)], platinum is coordinated to the BO unit. ^[5] In this compound the BO bond length is 120 picometers.

References

1. Inorganic chemistry, Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman
2. Westcott, S. A. (2010), BO Chemistry Comes Full Circle. Angewandte Chemie International Edition, 49: 9045–9046. doi : 10.1002/anie.201003379
3. Synthesis and Characterization of a Coordinated Oxoborane: Lewis Acid Stabilization of a Boron−Oxygen Double Bond Dragoslav Vidovic, Jennifer A. Moore, Jamie N. Jones, and Alan H. Cowley J. Am. Chem. Soc., 2005, 127 (13), pp 4566–4567 doi : 10.1021/ja0507564
4. Wang, Y., Hu, H., Zhang, J. and Cui, C., Comparison of Anionic and Lewis Acid Stabilized N-Heterocyclic Oxoboranes: Their Facile Synthesis from a Borinic Acid. Angewandte Chemie, n/a. doi : 10.1002/ange.201007417
5. Oxoboryl Complexes: Boron−Oxygen Triple Bonds Stabilized in the Coordination Sphere of Platinum Holger Braunschweig, Krzysztof Radacki and Achim Schneider Science 16 April 2010 Vol. 328 no. 5976 pp. 345-347 doi : 10.1126/science.1186028