Two new C, N, N-type ligands (HL2 and HL3), containing a Cphenyl, a Npyridyl, and a Nimidazolyl donor, and their cycloplatinated complexes,[Pt (L2) Cl](1),[Pt (L3) Cl](2),[Pt (L2)(PPh3)]+(3) and [Pt (L3)(PPh3)]+(4), have been successfully synthesized and characterized. Spectroscopic and 3MLCT luminescent properties of these Pt (II) cyclometalated complexes were found to be pH dependent. This was attributed to the ...