Synthesis, crystal structure and photophysical properties of a novel Pt(II) complex with multi-functionalized cyclometalating ligand

A novel Pt(II) complex [(L)PtCl] (HL = 4-{p-[N-(4-(9-carbazole))butyl-N-phenyl] aniline}-6-phenyl-2,2′-bipyridine) has been synthesized and verified by 1H NMR, elemental analysis and X-ray crystallography. The crystal (C44H35N4ClPt, Mr = 850.30) belongs to monoclinic system, space group P2(1)/c, with a = 21.864(6), b = 9.306(3), c = 17.240(5) Å, β = 96.483(6)°, Z = 4, V = 3485.3(16) Å3, DC = 1.620 g/cm3, μ(Mo-Kα) = 4.141 mm− 1, F(000) = 1688, R1 = 0.0591, wR2 = 0.0976. The coordinate geometry of the Pt atom is a distorted square planar configuration. The complex molecules are stacked by a weak π–π interaction in a head-to-tail fashion along the b axis to form 1D chain and the alternating 1D chains are packed to form the 2D lamellar system. The complex shows an intense metal-to-ligand charge transfer (1MLCT) (dπ(Pt) → π*(L)) transitions (ε ∼ 2 × 104 dm3 mol− 1 cm− 1) at 448 nm in the UV–Vis absorption spectrum and a strong phosphorescence at 592 nm in CH2Cl2 solution at room temperature. An intramolecular energy transfer process from the carbazole unit to the arylamine-modified [(C^N^N)PtCl] emissive center exists in the complex.

Graphical abstractThe tri-component C^N^N Pt (II) complex: the neutral-charged C^N^N Pt (II) halide with aniline and carbazole functionalized cyclometalating ligand form 1D chains in a head-to-tail fashion along the b axis by weak π–π interactions and 2D lamellar system. The complex shows a intense metal-to-ligand charge transfer (1MLCT) (dπ(Pt) → π*(L)) transitions at 448 nm in the UV–Vis absorption spectrum and a strong phosphorescence at 592 nm in CH2Cl2 solution at room temperature.Figure optionsDownload full-size imageDownload as PowerPoint slide