Palladium(II) complexes of N-[(2-pyridyl)methyliden]-α(or β)-aminonaphthalene: Single crystal X-ray structure of di-chloro-N-[{(2-pyridyl)methyliden}-β-aminonaphthalene]palladium(II), Pd(β-NaiPy)Cl2, spectra and DFT, TD-DFT study

Palladium(II) complexes of N-[(2-pyridyl)methyliden]-α(or β)-aminonaphthalene (α or β-NaiPy) are reported in this work. They are spectroscopically characterized along with some mixed ligand complexes, using diimine and azoimine functions. The single crystal X-ray structure of [Pd(N-(2-pyridyl)methyliden-β-aminonaphthalene)Cl2] has been determined. Luminescence properties of the complexes exhibit a ligand centered π–π∗ emission. Quantum yields (ϕ) have been calculated and it has been observed that the complexes of α-NaiPy show higher ϕ values than the complexes of β-NaiPy. Lifetime measurements suggest bi-exponential decay and the average fluorescence lifetime varies from 1.4 to 6.8 ns. The spectroscopic properties are correlated with DFT and TD-DFT calculations in two complexes, Pd(β-NaiPy)X2 (X = Cl, I) and they are compared with the free ligand results.

Graphical abstract(N-[(2-Pyridyl)methyliden]-α(and β)-aminonaphthalene (α/β-NaiPy)) are used to prepare palladium(II) complexes. The structures of the complexes are established by spectroscopic (FTIR, UV–Vis, NMR) studies and in one case by the single crystal X-ray diffraction technique. Ligands and complexes are photoluminescent. They exhibit decay following a bi-exponential route and lifetime in ns units.Figure optionsDownload full-size imageDownload as PowerPoint slide