This paper presents the case studies on the syntheses and characterization of three third-row transition metal complexes, all of them are associated with at least one functionalized 2-pyridyl pyrazolate chelates. Each of these complexes possesses distinctive central metal atom and shows highly efficient phosphorescent emission ranging from red, green and blue of the visible spectrum. Their photophysical properties are briefly discussed, including the assignment of their fundamental absorption and emission characteristics. Finally, performance data on fabrication of phosphorescent OLEDs using these complexes as emitters are presented.