Interaction of free functional group with platinum(II) center in cyclometalated complexes: A structural and photophysical property investigation

Flexible multidentate ligands containing N,P-donors, 2-[N-(diphenylphosphino)methyl]amino-pyridine (L1), 2-[N-bi-(diphenylphosphino) methyl]amino-pyridine (L2), 2-[N-(diphenylphosphino)methyl]amino-7-methyl-1,8-naphthyridine (L3) and 4-[(N-diphenylphosphino)methyl]amino-pyridine) (L4) as well as their mono- and dinuclear cyclometalated platinum(II) complexes [Pt(C^N^N)L1]ClO4 (HC^N^N=6-phenyl-2,2′-bipyridine), [Pt2(C^N^N)2L1](ClO4)2, [Pt2(C^N^N)2L2](ClO4)2, [Pt(C^N^N)L3]ClO4 and [Pt2(C^N^N)2L4](ClO4)2 were synthesized and characterized. The non-radiative decay process of these photoexcited platinum(II) complexes can be systematically tuned by controlling the intramolecular interaction between the N-donor of auxiliary ligands and the platinum(II) center.