Design and synthesis of iridium(III) azacrown complex: application as a highly sensitive metal cation phosphorescence sensor

A new metal cation probe 1 bearing a central Ir(iii) element and 1-aza-15-crown-5-ether substituted pyridyl pyrazolate as the chelate was synthesized. The octahedral molecular structure of 1 was confirmed using single crystal X-ray diffraction analyses. Subsequent photophysical study showed yellow-green emission at ∼560 nm in both fluid solution and solid state at room temperature. Remarkable differentiation in spectral properties upon metal cation (e.g. Ca²⁺) complexation makes complex 1 a highly sensitive phosphorescence probe.