“Ship in a bottle” complexes as precursors for preparing nano-oxide materials

Abstract

Amine nickel(II) complexes can exhibit not only unique structural-directing role in the crystallization of open-framework aluminophosphate lattice but also act as precursors for obtaining very fine nano-oxide particles. The constraints imposed by pore openings of the lattice seem to be crucial in the prevention of agglomeration of nano particles. Thermal decomposition of two diamine nickel(II) complexes captured inside AlPO4-34 and AlPO4-5 frameworks leads to crystallization of nickel(II) oxide particles with the cubic structure (JCPDF # 78-0643) outside the channels. The homogeneously dispersed particles do not interact with the host lattice nor deform it. The size of the crystallites shows a dependence on the host structural type. The nickel oxide particles crystallized in the chabazite matrix are up to 5 nm whereas the particles formed on the AlPO4-5 surface are of about 10 nm in size. This can be explained by differences in the pore openings of the aluminophosphate host.