2D NOESY OF PALLADIUM PI-ALLYL COMPLEXES - REPORTER LIGANDS, COMPLEX DYNAMICS, AND THE X-RAY STRUCTURE OF [PD(ETA-3-C4H7)(BPY)](CF3SO3) (BPY = BIPYRIDINE)

Cationic Complexes of the type Pd(eta-3-C4H7)(N N)+ (C4H7 = CH2C(CH3)CH2; N N = a variety of nitrogen chelates) have been studied by H-1 2D NOESY. The strengths and weaknesses of the concept of reporter ligands are discussed, and the allyl C-H rehybridization found in earlier studies is confirmed for the eta-3-(2-methylallyl) ligand. Aspects of the dynamics of these cations are discussed. Calculations for Pd(eta-3-C4H7)(bpy)+ (bpy = bipyridine), based partially on the solution NOE results, afford a solution structure, which is in good agreement with the structure (CF3SO3 anion) determined by X-ray diffraction methods. The complex crystallized in the space group P2(1)/c with a = 7.185 (1) angstrom, b = 16.762 (1) angstrom, c = 14.811 (1) angstrom, beta = 95.593 (9)degrees, V = 1775.3 angstrom 3, and Z = 4. Selected bond distances: Pd-N(1) = 2.089 (2) angstrom, Pd-N(2) = 2.085 (3) angstrom, Pd-C(7) = 2.095 (4) angstrom, Pd-C(8) = 2.123 (4) angstrom, and Pd-C(9) = 2.112 (4) angstrom. From both the solution and solid-state structures we find distances from the bipyridine ortho proton, H(6), to the allyl syn and anti protons to be ca. 2.8-2.9 and 3.1-3.5 angstrom, respectively.