FLUXIONAL BEHAVIOR OF CATIONIC CIS-BIS(ETHER-PHOSPHANE)PALLADIUM(II) COMPLEXES - P-31-DNMR SPECTROSCOPIC INVESTIGATIONS, LINE-SHAPE ANALYSIS, AND DETERMINATION OF REARRANGEMENT BARRIERS

Reaction of X2Pd(P is similar to O)2 (X = Cl:1a-g, k-n, p; X = Br:1'; X = I:k'', 1'', o'') with stoichiometric amounts of AgClO4 results in the formation of the monochelate complexes cis-[ClPd(P is similar to O )(P and O)][ClO4] (2a-g, k-n, p, 1', 1'') (P is similar to O: eta1-P-c oordinated; P and O: eta2-O,P-chelated). In the case of compounds 1 o, 1 k'', and 1 o'', which are provided with less basic etherphosphanes, the halide-bridged dimers [(mu-X)Pd(P is similar to O)2]2[ClO4]2 (3 o , k'', o'') are obtained. Temperature-dependent P-31{H-1}-NMR spectra of the fluxional complexes 2a-g, k-n, p, 1', 1'' lead to DELTAG(not-eq ual) values. By using a modified version of DNMR5, computer-generated spectra of 2a, b, f, k, 1, p, 1', 1'' were obtained and fitted to the experimental spectra. Graphic application of the Eyring equation to th e kinetic data afforded the thermodynamic parameters DELTAH(not-equal) DELTAS(not-equal), and DELTAG(not-equal). The DELTAS(not-equal) value s are in agreement with an associative exchange mechanism for 2a, b, f , 1, p, 1', 1'' and with a dissociative exchange mechanism for 2k. 2k and 3 o crystallize in the monoclinic and triclinic space group P2(1)/ c and P1BAR with Z = 4 and Z = 2, respectively.