An Approach to the Synthesis of Polyoxometalate Encapsulating Different Kinds of Oxoanions as Heteroions: Bisphosphitopyrophosphatotriacontamolybdate [(HPO3)(2)(P2O7)Mo30O90](8-)

Maeda S; Goto T; Takamoto M; Eda K; Himeno S; Takahashi H; Hori T

Inorganic Chemistry, Vol.47, No.23, 11197-11201, 2008

Maeda S, Goto T, Takamoto M, Eda K, Himeno S, Takahashi H, Hori T

A yellow [(HPO3)(2)(P2O7)Mo30O90](8-) anion was prepared as a tetrapropylammonium (Pr4N+) salt from a 50 mM Mo-VI-2 mM P2O74--4 mM HPO32--0.95 M HCl-60% (v/v) CH3CN system at ambient temperature. The (Pr4N)(8)[(HPO3)(2)(P2O7)Mo30O90] salt crystallized in the orthorhombic space group P-nma (No. 62), with a = 30.827(2) angstrom, b = 22.8060(15) angstrom, c = 30.928(2) angstrom, V = 21743(3) angstrom(3), and Z = 4. The structure contained a (P2O7)Mo12O42 fragment derived from the removal of each corner-shared Mo3O13 unit in a polar position from a [(P2O7)Mo18O54](4-) structure, and each side of the (P2O7)Mo12O42 fragment was capped by a B-type (HPO3)Mo9O24 unit. The [(HPO3)(2)(P2O7)Mo30O90](8-) anion was characterized by voltammetry and IR, UV-vis, and P-31 NMR spectroscopy. Unlike the Keggin and Dawson anions and the parent [(P2O7)Mo18O54](4-) anion, the [(HPO3)(2)(P2O7)Mo30O90](8-) anion exhibited two-electron redox waves in CH3CN with and without acid.