HIGHLY OXIDATION RESISTANT INORGANIC-PORPHYRIN ANALOG POLYOXOMETALATE OXIDATION CATALYSTS .1. THE SYNTHESIS AND CHARACTERIZATION OF AQUEOUS-SOLUBLE POTASSIUM-SALTS OF ALPHA-2-P2W17O61(MN+.OH2)(N-10) AND ORGANIC-SOLVENT SOLUBLE TETRA-NORMAL-BUTYLAMMONIUM SALTS OF ALPHA-2-P2W17O61(MN+.BR)(N-11) (M = MN3+, FE3+, CO2+, NI2+, CU2+)

The synthesis and characterization of isolated, isomerically pure alpha-2-P2W17O61(Mn+.L)y- (Mn+ = Mn3+, Fe3+, Co2+, Ni2+, and Cu2+) as aqueous-soluble potassium salts (L = H2O) and organic-soluble tetra-n-butylammonium salts (L = Br-) are reported. These complexes have been characterized by P-31 NMR, elemental analysis, sedimentation equilibrium molecular weight, thermal gravimetric analysis (TGA), temperature-varied solid-state magnetic susceptibility studies, UV-visible spectroscopy, infrared spectroscopy (IR), and W-183 NMR. These compounds constitute the first isolated monosubstituted Dawson alpha-2-isomer complexes that have been prepared free of the alpha-1-isomer. Preliminary axial-base binding studies for alpha-2-[(n-C4H9)4N]7.3H0.7P2W17O61(Mn.Br) are reported and demonstrate that the ''pocket'' around the transition metal is actually somewhat hindered, but less so than in sterically congested porphyrins. Further studies show that alpha-2-[(n-C4H9)4N]7.3H0.7P2W17O61(Mn.Br) is not oxidatively degraded by 1500 equiv of PhIO even over 48 h. In an accompanying paper, oxidation catalysis by alpha-2-P2W17O61(M.L)y- is reported yielding olefin epoxidations and aliphatic and aromatic hydroxylations.