A new metal cation probe 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 was confirmed using single crystal X-ray diffraction analyses. Subsequent photophysical study showed yellow-green emission at approximately 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 a highly sensitive phosphorescence probe.