Molecular sensing behavior of the first Mn(I)-compound of di-2-pyridylketone-p-nitrophenylhydrazone (dpknph), fac-[Mn(CO)3(dpknph)Br]

Optical and thermodynamic measurement on fac-Mn(CO)3(dpknph)Br in polar solvents reveal reversible interconversion between two intense electronic states and use as an optical sensor. Group 12 metal ions in concentration as low as 1.0 × 10−9 M can be detected and determined using fac-Mn(CO)3(dpknph)Br in polar solvents.