Nitrogen- versus carbon-coordination of the alpha-cyano-stabilized phosphorous ylide Ph3P=C(H)CN. X-ray crystal structure of (Pd(dmba)(P(OMe)3)(N-triple bond-C-C(H)=PPh3))(ClO4)

X-ray crystallography, infrared and nuclear magnetic resonance spectroscopic analyses were done to characterize the cationic derivatives of (Pd(dmba)(P(OMe)3)(N-triple bond-C-C(H)=PPh3))(ClO4) in which the ylide ligand is N-coordinated to the Pd(super II) center and trans to the ortho-metalated C6H4 group, in an 'end-on nitrile' coordination mode. The reaction of the cationic (Pd(CN)(NCMe)2)+ with Ph3P=C(H)CN in a 1:2 molar ration yielded bis(ylide) complexes in which one ylide is N-coordinated and the other is C-coordinated. When the reaction was done in a 1:1 molar ratio, the products contained the ylide which served as a C,N-bridging system.