Rational bottorritup construction of two-dimensional (2D) covalent or nonCovalent organic materials with precise structural control at the: atomic or molecular level remains a challenge. The design and synthesis of metal organic frameworks (MOFS) based on new building blocks is of great significance in achieving new types of 2D monolayer MOF films. Here, we demonstrate that a complexation between copper(II) ions and tri(beta-diketone) ligands yields a novel 2D MOF siyucture, either-inthe form of a powder.or.as a monolayer filth. It has been Characterized by Fourier transform infrared, Raman, ultraviolet-visible, X-ray photoelectron, and electron paramagnetic-resonance spectroscopies. Selected area electron diffraction and powder X-ray diffraction results show that the MOF is Crystalline and has a hexagonal structure. A MOF-based membrane has been prepared by vacuum filtration of an aqueous dispersion of the MOF powder onto a porous Anodisc filter having pore-size 0.02 mu m. The porous MOF membrane filters gold nanOparticies with a cutoff of similar to 2.4 nm.