Cleavage of Two Hydrogen Molecules by Boryldisilenes.

Activation of H2 by compounds of main-group elements has received considerable attention. Herein, we report synthesis of novel monoboryl- and monoamino-substituted disilenes and their characterization by a combination of NMR spectroscopy and single-crystal X-ray diffraction analysis. The monoboryldisilene reacts with two molecules of H2 to provide the corresponding trihydridodisilane and hydroborane, whereas the aminodisilene does not react with H2 under the same conditions. The present results together with our previous results indicate that the presence of the boryl-substituent on the Si=Si double bond is essential to activate the H2 molecule. The low lying empty 2p orbital on the boron atom that interacts effectively with the π*(Si=Si) orbital could be responsible for the activation of H2 .