10.1021/om0306123.s001 Mark R. St.-J. Foreman Mark R. St.-J. Foreman Anthony F. Hill Anthony F. Hill P. White P. White David J. Williams David J. Williams Polyazolyl Chelate Chemistry. 13. An Osmaboratrane<sup>1</sup> American Chemical Society 2004 crystal structure Na benzene elimination boron 13. methimazolyl osmium Osmaboratrane 1 Polyazolyl Chelate Chemistry formation Cl transannular dative bond mt osmaboratrane 2004-02-16 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Polyazolyl_Chelate_Chemistry_13_An_Osmaboratrane_sup_1_sup_/3349930 The reaction of [Os(C<sub>6</sub>H<sub>5</sub>)Cl(CO)(PPh<sub>3</sub>)<sub>2</sub>] with Na[HB(mt)<sub>3</sub>] (mt = methimazolyl) results in benzene elimination and the formation of the first osmaboratrane [B(mt)<sub>3</sub>Os(CO)(PPh<sub>3</sub>)](<i>Os</i>→<i>B</i>), the crystal structure of which reveals a somewhat long transannular dative bond between osmium(0) and boron(III).