Two new C,N,N-type ligands (HL 2 and HL 3), containing a C phenyl, a N pyridyl, and a N imidazolyl donor, and their cycloplatinated complexes, [Pt(L 2)Cl] (1), [Pt(L 3)Cl] (2), [Pt(L 2)(PPh 3)] + (3) and [Pt(L 3)(PPh 3)] + (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 protonation/deprotonation of the acidic 1-imidazolyl-NH moieties on the ligands. All the cycloplatinated complexes (both protonated and deprotonated forms) possessed two-photon excitability with two-photon absorption cross-sections ranging from 6.0 to 30.0 GM (protonated forms) and from 16.2 to 24.9 GM (deprotonated forms).
Scopus Subject Areas
- Inorganic Chemistry