| In Part I, it is demonstrated that stoichiometric amounts of phase transfer agents (quaternary ammonium salts) are sufficient for the complete transfer of the heteropoly anions XW(,11)O(,39)Z(OH(,2))('m-) (X = B, Si, Ge, P, and Z = CO('II), Co('III), Cu('II), Mn('II), Mn('III)), P(,2)W(,17)O(,61)Z(OH(,2))('n-) (Z = Co('II), Mn('II)), P(,2)W(,18)O(,68)Co(,4)(OH(,2))('10-) and SiW(,9)O(,37)Co(,3)(OH(,2))(,3)('10-) into nonpolar solvents such as benzene and toluene.; Dehydration of the nonpolar solutions (ca. 10('-2) M in polyanion) by passage of dry Ar or N(,2), vacuum, or the use of drying agents results in the complete or partial removal of the water molecules coordinated to Z. The ease of dehydration depends upon both X and Z and also varies with the overall charge of the anion.; Spectroscopic studies show that ligands like pyridine or Cl('-) coordinate to the unsaturated sites, forming more stable complexes than in water. Gaseous SO(,2) binds irreversibly to the cobalt and copper sites (except for P(,2)W(,18)Co(,4)('10-) where reversible behavior was observed), and on the basis of IR diagnostic features and theoretical considerations an S-bonded complex is suggested.; The XW(,11)O(,39)Mn('6-) (X = Si, Ge), anions form reversible oxygen adducts below -35(DEGREES)C and room temperature respectively when dried solutions are exposed to molecular oxygen. Visible, and ESR spectroscopy, magnetic measurements, and spin trapping experiments suggest the formation of a mononuclear "superoxo"-type of adduct. Upon standing or at higher temperatures the corresponding Mn('III) complexes are produced. The relative stability of the oxygen complexes appears to be related to the redox potential of Mn(II) which in turn depends upon X(P, Si, Ge, B).; In Part II, heteropoly molybdate complexes of some monophosphates of biological significance (adenosine monophosphate, uridine monophosphate, flavin mononucleotide, (beta)-glycerophosphate) were prepared and characterized. Analytical, spectroscopic and electrochemical results suggest that the complexes adopt the (RPO(,3))(,2)MoO(,15)('4-) structure. The polyphosphates P(,2)O(,7)('4-), adenosine diphosphate, and adenosine triphosphate under analogous conditions do not form stable complexes, but are hydrolyzed to orthophosphate. |
