Reactions of 1-((2-hydroxy-5-R-phenylimino)methyl)naphthalen-2-ols (H
2L
n,
n = 1–3 for R = H, Me, Cl, respectively) with [Pd(PPh
3)
2Cl
2] and Et
3N in toluene under reflux produced three new mononuclear square-planar palladium(II) complexes with the general formula [Pd(L
n)(PPh
3)] (
, R = H;
, R = Me;
, R = Cl). All the complexes were characterized using
elemental analysis, solution conductivity and various spectroscopic (infrared, UV–visible and NMR) measurements. Molecular structures of
were confirmed using single-crystal X-ray diffraction analysis. In each complex, the fused 5,6-membered chelate rings forming phenolate-O, azomethine-N and naphtholate-O donor (L
n)
2− and the PPh
3 form a square-planar ONOP coordination environment around the metal centre. Infrared and NMR spectroscopic features of
are consistent with their molecular structures. Electronic spectra of the three complexes display several strong primarily ligand-centred absorption bands in the range 322–476 nm. All the complexes were found to be effective catalysts for
carbon–
carbon cross-coupling reactions of arylboronic acids with aromatic and heteroaromatic aldehydes to form the corresponding diaryl ketones. Copyright