Halogen ligands exchange in palladium(II) acyclic diaminocarbene complexes and their stereochemistry.

Palladium(II) diaminocarbene complexes trans -[PdI 2 (CNXyl){C(NHXyl) = NHNHC(O)R}] ( 4a – h ) bearing iodide anionic ligands were synthesised via ligands exchange from the corresponding chloride species cis -[PdCl 2 (CNXyl){C(NHXyl) NHNHC(O)R}] ( 3a – h ) and KI in an acetone solution. Complexes 4a – h were isolated and characterized by HRESI + -MS, IR, 1 H and 13 C{ 1 H} NMR spectroscopies, and single-crystal X-ray diffraction (in the case of complexes 4a – e , 4g and 4h ). The entire synthesised compounds exhibit slightly distorted square planar geometry around the metal centre. The carbene and isocyanide ligands in the synthesised iodide complexes are in trans -position each other in contrast to the starting cis -dichloride species. [ABSTRACT FROM AUTHOR]