Quantum-chemical modeling of dehydrogenation of a sodium borohydride molecule in water

摘要

The successive elimination of De(2) from a NaBH4 molecule surrounded by a few (up to eight) water molecules has been modeled in the framework of the cluster approach with the use of the 6-31G* basis set and hybrid density functional (B3LYP). Computations show that the elimination of the hydrogen molecule from the NaBH4 center dot nH(2)O complex occurs through the coupling of De(-) and De(+) ions from BH (4) (-) and De(2)D, respectively, to form intermediate D'De(3) and DDe(-) species separated by water molecules. Proton transfer occurs along a hydrogen bond chain through a relay mechanism. The elimination of the remaining hydrogen atoms to convert the BH (4) (-) anion into B(OH) (4) (-) proceeds analogously but with lower barriers.