Two palladium(II) complexes based on Schiff base ligands: synthesis, characterization, luminescence, and catalytic activity

Abstract

Two Pd(II) complexes involving Schiff base ligands, namely, [Pd(L1)2] (1), [Pd2(L2)Cl2] (2) [HL1 = 2-((2,6-diisopropylphenylimino)methyl)-4,6-dibromophenol, L2 = N-(4-isopropylbenzylidene)-2,6-diisopropylbenzenamine] have been synthesized using solvothermal methods and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction, UV–vis absorption spectra, and single-crystal X-ray diffraction. Complex 1 is a mononuclear cyclometalated Pd(II) complex, whereas complex 2 is a μ-chloro-bridged dinuclear. Both 1 and 2 display photoluminescence in the solid state at 298 K and possess fluorescence lifetimes (τ 1 = 86.40 ns, τ 2 = 196.21 ns, τ 3 = 1,923.31 ns at 768 nm for 1, τ 1 = 69.92 ns, τ 2 = 136.40 ns, τ 3 = 1,714.26 ns at 570 nm for 2). The Suzuki reactions of 4-bromotoluene with phenylboronic acid by complexes 1–2 have also been studied.