trans-Diaquabis(l-phenylalaninato-κ2N,O)nickel(II)

In the title compound, [Ni(C9H10NO2)2(H2O)2], the coordination geometry around the NiII ion can be described as distorted octahedral, with two N atoms and two O atoms from phenylalaninate ligands in the basal plane and two aqua O atoms at the axial sites. The crystal packing is stabilized by intermolecular O—H...O and N—H...O hydrogen bonds

Diaquabis( L

L-Phenylalanine reacts with nickel-exchanged zeolite Y to form diaquabis(L-phenylalaninato)nickel(II), which is encapsulated in the pores of the zeolite. In this zeolite-encapsulated form, the nickel derivative functions as an efficient catalyst when cyclohexene, toluene and ethyl benzene are oxidized by hydrogen peroxide in the presence of sodium bicarbonate (as co-catalyst). The catalyst was readily recovered from the reaction mixture, and it could be re-used for other three runs without noticeable loss of activity. The heterogeneous catalyst exhibited significantly higher activity and selectivity compared with diaquabis(L-phenylalaninato)nickel(II) itself