Chiral [Mo₈O₂₆]⁴– Polyoxoanion-Induced Three-Dimensional Architectures With Homochiral Eight-Fold Interpenetrated Metal–Organic Frameworks

A pair of novel chiral compounds based on homochiral 8-fold interpenetrated metal–organic frameworks (MOFs) and chiral polyoxometalates (POMs), formulated as d -[Cu(4,4′-bipy) 1.5 ] 4 [Mo 8 O 26 ] ( d - 1 ) and l -[Cu(4,4′-bipy) 1.5 ] 4 [Mo 8 O 26 ] ( l - 1 ) (4,4′-bipy = 4,4′-bipyridine), have been successfully synthesized and characterized by single crystal X-ray diffraction, infrared, thermogravimetric analysis, elemental analysis, and solid circular dichroism spectra. Structural analysis indicates that two compounds are enantiomers. The connection of copper cations and 4,4′-bipy ligands generates helical infinite chains, while adjacent chains are further linked by Cu–N bonds to form a three-dimensional interpenetrating framework with a (10,3)-a topology. Interestingly, the chiral [Mo 8 O 26 ] 4– polyanions are encapsulated in the chiral MOFs via sharing the oxygen atoms. Both d - and l -[Cu(4,4′-bipy) 1.5 ] 4 [Mo 8 O 26 ] crystallize in chiral space group C 222 1 . Additionally, two compounds represent new examples of chiral self-assembly.