The paddlewheel complex of 1,8-naphthyridine and palladium(II)

This work presents the synthesis of the tetracationic paddlewheel complex of 1,8-naphthyridine and palladium(II), [Pd₂(µ-napy)₄]X₄, (X = BF₄⁻ or PF₆⁻). Single-crystal X-ray diffraction confirms a D_4h symmetric paddlewheel structure encompassing the two Pd units in the metal core coordinated by four ditopic 1,8-naphthyridine ligands, featuring a relatively short Pd–Pd distance. Spectroscopic analyses combined with density-functional theory (DFT) provide insights into the nature of the Pd–Pd and Pd–Napy interactions as well as observed optical absorption frequencies.