Cr2O72− inside Zr/Hf-based metal–organic frameworks: highly sensitive and selective detection and crystallographic evidence

The (4,8)-connected Zr/Hf-MOFs exhibit excellent performances in the detection of Cr₂O₇²⁻ and the exact location and configuration of Cr₂O₇²⁻ inside the MOFs were revealed by single-crystal X-ray diffraction studies for the first time.