Synthesis of the MIL-101 framework has been attempted from different trivalent metal ions, rather than Cr, like: Fe, Al, V, Ti, Sc, and Mn. In addition, the amino-functionalized form has been successfully reported for some of them.
Hydroxyl-functionalized homo- and co-polyimides 6FDA–(DAM) x –(HAB) y (with x : y molar ratio of 1 : 0; 2 : 1; 1 : 1; 1 : 2) and two metal–organic frameworks (MOFs), MIL-53(Al) and NH 2 -MIL-53(Al) were synthesized for preparation of mixed matrix membranes (MMMs).