Metal Complexes of pi-Expanded Ligand (7): Syntheses, Structures and Properties of Pt(II) Complexes Containing the Isomeric 1-and 2-Alkyliminomethyl Pyrene Ligands

A [O,N] bidentate pi-expanded ligand system, (E)-1-(n-octylimino)methylpyren-2-ol (2), was newly synthesized via a six-step synthesis from pyrene. The ligand2reacts with [PtCl2(PhCN)(2)] in chlorobenzene and the presence of a base at reflux for 2 h under the formation of (2(Pt)) complex with a yield of 70%. The molecular structure of (2(Pt)), studied by common spectroscopic methods and X-ray diffraction, shows a square planar geometry with a trans-configuration of the ligands. The molecular structure, absorption spectra, electrochemical properties, and phosphorescence characteristics of the (2(Pt)) complex are discussed, emphasizing the comparison with those of the previously reported Pt complex (1(Pt)) containing the isomeric ligands of2, (E)-2-(n-octylimino)methylpyren-1-ol. The DFT calculations of the two Pt complexes are carried out and exhibit a clear explanation of the relationship between their physico-chemical characteristics.