Dimethylphosphinato and Dimethylarsinato Complexes of Palladium(II), [Pd(Me 2 PO 2 ) 2 ] 3 and Pd(Me 2 AsO 2 ) 2 , and their Adducts

The complexes [Pd(Me 2 PO 2 ) 2 ] 3 and Pd(Me 2 AsO 2 ) 2 were prepared from the corresponding acids and palladium(II) acetate. Their structures were deduced by IR and NMR spectroscopy. Addition of pyridine and 2,2′‐bipyridine to [Pd(Me 2 PO 2 ) 2 ] 3 gave the adducts Pd(Me 2 PO 2 ) 2 py 2 and Pd(Me 2 PO 2 ) 2 bipy, which were characterized by 1 H NMR spectroscopy. Addition of nicotinic acid and nicotinamide in water gave the adducts Pd(Me 2 PO 2 ) 2 L 2 , whereas in methanol the adducts Pd(Me 2 PO 2 ) 2 L were obtained. The cacodylate containing complex formed the adducts Pd(Me 2 AsO 2 ) 2 py and Pd(Me 2 AsO 2 ) 2 bipy 1/2 , which are unstable in CDCl 3 . Triphenylphosphine deoxygenated both Pd(Me 2 MO 2 ) 2 complexes, but the palladium(II) containing products could not be isolated. The expected Pd(Me 2 P–O) 2 reacted further and gave many products, whereas the anticipated Pd(Me 2 As–O) 2 did not bind triphenylphosphine.