Multifunctional Anthracene-Based Ni-MOF with Encapsulated Fullerenes: Polarized Fluorescence Emission and Selective Separation of C-70 from C-60

We report an anthracene-based Ni-MOF [Ni(II) metal-organic framework, {[Ni(/mu(2)-L)(2)Cl-2]center dot x(C6H6)y(MeOH)}(n) (1), L = anthracene-9,10-diyIbis(methylene)diisonicotinate whose crystal structure reveals the presence of hexagonal channels with a pore size of 1.4 nm that can accommodate guests such as C-60 and C-70. Both confocal fluorescence and Raman microscopy results are in agreement with a homogeneous distribution of fullerenes throughout the single crystals of 1. Efficient energy transfer from 1 to the fullerenes was observed, which emitted partially polarized fluorescence emission. Stronger binding between 1 and C-70 versus C-60 was confirmed from HPLC analysis of the dissolved material and provides a basis for the selective retention of C-70 in liquid chromatography columns packed with 1.