pi-2-Methylallylpalladium(II) complexes containing a nine-membered chelate ring with an azine diphosphine ligand: Crystal structure of [(eta(3)-2-MeC(3)H(4))Pd{E,Z-PPh(2)CH(2)C(Bu(t))=N-N=C(Bu(t))CH(2)PPh(2)}]Cl

Treatment of the azine diphosphine Z,Z-PPh(2)CH(2)C(Bu')=N-N=C(Bu')CH(2)PPh(2) (1) with 0.5 equiv. of [{(eta(3)-2-MeC(3)H(4))PdCl}(2)] gave the cationic palladium(II) complex [(eta(3)-2-MeC(3)H(4))Pd{PPh(2)CH(2)C(Bu')=N-N=C(Bu')CH(2)PPh(2)}]Cl (2a), containing a nine-membered chelate ring with the azine in the E,Z-configuration, The crystal structure of 2a shows that the E,Z-azine backbone C-C=N-N=C-C is essentially planar and the methylallyl ligand is non-planar. The corresponding PF6 salt 2b was prepared using NH4PF6 in EtOH. The proton NMR spectra of 2b were temperature dependent, and at 243 K the slow exchange limiting spectrum was obtained in which all four CH2P protons were inequivalent, as were the four allylic protons with (4)J(HsynHsyn)=2.2 Hz. Proton, P-31{H-1} and C-13{H-1} NMR data are given. Crystals of 2a are monoclinic, space group P2(1)/n with a=10.3449(8), b=18.457(2), c=21.705(2) Angstrom, beta=101.140(7)degrees and Z=4, R(1)=0.0495 for 5769 observed reflections with I>2.0 sigma (I).