Abstract
The reaction of tBu(2)P(O)H with Bis(2)AlH (Bis = CH(SiMe(3))(2)) afforded the adduct tBu(2)P(H)-O-Al(H)Bis(2) (3). It slowly releases H(2) to form the first oxygen-bridged geminal Al/P frustrated Lewis pair tBu(2)P-O-AlBis(2). It is capable of reversibly binding molecular hydrogen to afford 3, shown by NMR and H/D scrambling experiments, and forms a 1,2-adduct with CO(2). Importantly, the H(2) adduct 3 reduces CO(2) in a stoichiometric reaction leading to the formic acid adduct tBu(2)P(H)-O-Al(CO(2)H)Bis(2). The formation of the different species was explored by density functional theory calculations which provide support for the experimental results. All products were characterized by NMR spectroscopy as well as X-ray diffraction experiments and elemental analyses.