Synthesis and characterization of new oxazoline-based palladacycles with bridging or terminal imidate ligands. Crystal structures of [{Pd(μ-dibromomaleimidate)(Phox)}2], [Pd(dibromomaleimidate)(Phox)(PPh3)] and [Pd(glutarimidate)(Phox)(PPh3)] (Phox = 2-(2

The dinuclear hydroxo complex [{Pd(μ-OH)(Phox)}2] (I) (Phox = 2-(2-oxazolinyl)phenyl) reacts in a 1:2 molar ratio with several imidate ligands to yield new cyclometallated palladium complexes [{Pd(μ-NCO)(Phox)}2] containing asymmetric imidate –NCO– bridging units. [–NCO– = succinimidate (succ) (1), phtalimidate (phtal) (2), maleimidate (mal) (3), 2,3-dibromomaleimidate (2,3-diBrmal) (4) and glutarimidate (glut) (5)]. The reaction of these complexes with tertiary phosphines provides novel mononuclear N-bonded imidate derivatives of the general formula [Pd(imidate)(Phox)(PR3)] [R = Ph (a), 4-F–C6H4 (b) or CH2CH2CN (c)]. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, FAB, 1H, 13C and 31P). The single-crystal structures of compounds 4, 4a and 5a have been established.

Graphical abstractThe dinuclear hydroxo complex [{Pd(μ-OH)(Phox)}2] has been used in the preparation of new cyclometallated palladium complexes [{Pd(μ-NCO)(Phox)}2] containing asymmetric imidate –NCO– bridging units. [–NCO– = succinimidate, phthalimidate, maleimidate, 2,3-dibromomaleimidate and glutarimidate]. The reaction of these complexes with tertiary phosphines provides novel mononuclear N-bonded imidate derivatives of the general formula [Pd(imidate)(Phox)(PR3)]. The first X-ray crystal structures of complexes containing 2,3 dibromomaleimide as ligand, showing different coordination modes, are presented.Figure optionsDownload full-size imageDownload as PowerPoint slide