Solid-state materials for anion sensing in aqueous solution: highly selective colorimetric and luminescence-based detection of perchlorate using a platinum(ii) salt

The PF6− salt of a platinum(II) complex changes from yellow to red and becomes intensely luminescent upon exposure to aqueous ClO4−. The response is remarkably selective. Spectroscopic changes are consistent with anion exchange resulting in shortening of the intramolecular Pt⋯Pt distances between the square planar cations.