A two-step process that differs in important details from previous methods used to prepare ZnMn 2 O 4 nanoplate assemblies has been reported. This material was prepared by thermal transformation of metal-organic nanoparticles into metal-oxide nanoparticles based on the ''escape-by-crafty-scheme'' strategy. Firstly, the nanoscale mixed-metal-organic frameworks (MMOFs) precursor, ZnMn 2 -ptcda (ptcda ¼ perylene-3,4,9,10-tetracarboxylic dianhydride), containing Zn 2+ and Mn 2+ , was prepared by the designed soft chemical assembly of mixed metal ions and organic ligands at a molecular scale. In a second step, the MMOFs are thermally transformed into spinel structured ZnMn 2 O 4 with morphology inherited from the MMOFs precursors. The well-crystallized spinel structure can be formed by thermal treatment of ZnMn 2 -ptcda at 350 C, and is formed at temperatures $450 C using the co-precipitation method. This ''escape-by-crafty-scheme'' strategy can be extended to the preparation of other spinel metal-oxide nanoparticles, e.g. CoMn 2 O 4 , and NiMn 2 O 4 , with well-defined morphology inherited from the metal-organic precursors. The ZnMn 2 O 4 nanoplate assemblies thermally treated at 450 C have potential application in lithium ion batteries as anode materials, which show high specific capacity and good cyclability.

Co 3 O 4 with high capacities and energy density has potential applications to be electrode materials for lithium ion batteries, one of the most important power sources. For improving the cycling stability, the Co 3 O 4 nanostructures are required. Herein, we report successful construction of Co 3 O 4 hexagonal nanorings and nanoplates/nanoparticles via treating Co-based metal organic frameworks (MOFs) with organic amine. The studies show that the release rate of Co(II) to the reaction system and the spatial hindrance of the organic linkers of MOFs determine the final morphology of Co 3 O 4 . As an anode for lithium ion batteries, Co 3 O 4 hexagonal nanorings with 1370 mA h g À1 specific capacity after 30 cycles displayed higher reversible capacity and better stability than commercial Co 3 O 4 particles with only 117 mA h g À1 specific capacity after 30 cycles. The improved performance of Co 3 O 4 hexagonal nanorings could be attributed to the shortened transfer path for Li + afforded by the special morphology.It is expected that plentiful metal oxide nanostructures could be constructed from MOFs due to the available versatile categories of MOFs.