Optical sensing of aqueous nitrate anion by a platinum(ii) triimine salt based solid state material

Abstract

Selective and quantitative measurement of aqueous nitrate (NO₃⁻) anion is achieved using solid [Pt(Cl-4-tpy)Cl]ClO₄ salt (Cl-4-tpy = 4-chloro-2,2′:6′2′′-terpyridine), and as the salt supported on controlled porous glass. This detection method relies on the color change of the Pt(II) complex from yellow to red and intense luminescence response upon ClO₄⁻ exchange with NO₃⁻ due to concomitant enhancement of Pt⋯Pt interactions. The spectroscopic response is highly selective for NO₃⁻ over a large range of halides and oxoanions.