Reactivity of Tetrahalo- and Difluorodiboranes(4) toward Lewis Basic Platinum(0): Bis(boryl), Borylborato, and Doubly Boryl-Bridged Platinum Complexes

摘要

The reaction of the tetrahalodiboranes(4) B2F4, B2Cl4, and B2Br4 with a Lewis basic platinum(0) complex led to the isolation of the cis-bis(difluoroboryl) complex cis-[(Cy3P)(2)Pt(BF2)(2)] (1) and the novel borylborato complexes trans-[(Cy3P)(2)Pt{B(X)-BX3}] (2, X = Cl; 3, X = Br), respectively. The trans influence of the borylborato group was found to be one of the strongest ever observed experimentally. Furthermore, the reactivity of little-explored diaryldifluorodiboranes(4) F2B-BMes(2) and the new derivative F2B-BAn(2) (An = 9-anthryl) toward a range of platinum(0) complexes was investigated. Reactions with relatively nonbulky platinum(0) complexes led to the formation of unsymmetrical cis-bis(boryl) complexes cis-[(R3P)(2)Pt(BF2)(BMes(2))] (6, R = Me; 7, R = Et) as well as the first example of a fourfold-unsymmetrical bis(boryl) complex, [(Me3P)(Cy3P)Pt(BF2)(BMes(2))] (12). The use of a more bulky Pt complex provided access to the unprecedented dinuclear bis(boryl) complexes [{(iPr(3)P)Pt}(2)(mu-BF2)(mu-BAr2)] (8, Ar = Mes; 9, Ar = An), which feature two different mu(2)-bridging boryl ligands.