Synthesis and characterization of Re-V, Re-VI and Re-VII complexes of the [alpha(2)-P2W17O61](10-) isomer

Rhenium-(V), -(VI) and -(VII) complexes of the [alpha(2)-P2W17O61](10-) iso mer, a mono-lacunary derivative of the [alpha-P2W18O61](6-) (Wells-Dawson) ion have been prepared and characterized by multinuclear NMR spectroscopy, electrospray mass spectrometry and electron paramagnetic resonance spectros copy, among other techniques. The molecules have the formulation [alpha(2)- ReOP2W17O61](n-), where n = 7,6,5 for Re-V, Re-VI and Re-VII, respectively. W-183 NMR spectroscopy for the Re-V and Re-VII analogs shows that the mole cules have C-s symmetry as expected for substitution in the alpha(2) site. Simulations of the X-band and Q-band EPR spectra of the Re-VI analog, using C-s symmetry, allow determination of the g, hyperfine and quadrupole coupl ing tensors. X-Band, Q-band and W-band EPR spectroscopy show extreme variat ions in linewidths due to random strains or distortions of the complex.