Reactions of bis[diphenyl-3-(4-methoxyphenylsydnonyl)]phosphine palladium chloride and amines and crystal analysis of its amine adducts

Reactions of bis[diphenyl-3-(4-methoxyphenylsydnonyl)]phosphine palladium chloride and amines yielded trans-amminedichloropalladium complexes, which were characterized by spectroscopic techniques (compounds 5–9) and X-ray diffraction (compounds 5 and 7). Bond lengths of PC(10), P-(16) decrease more than that of P-(1) after the complex is formed, suggesting that the phenyl rings are able to contribute more electron density to phosphorus for binding with Pd(II) than the sydnone ring. The equilibrium constants and rate constants for the reaction between complex 4 and amines depend not only on the basicity but also on the steric size of amines used.