Cu(I)-MOF: naked-eye colorimetric sensor for humidity and formaldehyde in single-crystal-to-single- crystal fashion

A porous Cu(I)-MOF was constructed from CuI and 1-benzimidazolyl-3,5-bis(4-pyridyl) benzene. This Cu(I)-MOF can be a highly sensitive naked-eye colorimetric sensor to successively detect water and formaldehyde species in a single-crystal-to-single-crystal fashion. Solid-state guest-responsive luminescence is also used to monitor the sensing process.