The gallium(III)-containing heteropolytungstates [Ga-4(H2O)(10)-(beta-XW9O33)(2)](6-) (X = As-III, 1; Sb-III, 2) were synthesized in aqueous acidic medium by reaction of Ga3+ ions with the trilacunary, lone-pair-containing XW9O33)(2)](9-). Polyanions 1 and 2 are isostructural and crystallized as the hydrated sodium salts Na-6[Ga-4(H2O)(10)(beta-AsW9O33)(2)]center dot 28H(2)O (Na-1) and Na-6[Ga-4(H2O)(10)(beta-SbW9O33)(2)]center dot 30H(2)O (Na-2) in the monoclinic space group P2(1)/c, with unit cell parameters a = 16.0218(12) angstrom, b = 15.2044(10) angstrom, c = 20.0821(12) A, and beta = 95.82(0)degrees, as well as a = 16.0912(5) angstrom, b = 15.2178(5) angstrom, c = 20.1047(5) angstrom, and beta = 96.2(0)degrees, respectively. The corresponding tellurium(IV) derivative [Ga-4(H2O)(10)(beta-TeW9O33)(2)](4-) (3) was also prepared, by direct reaction of sodium tungstate, tellurium(IV) oxide, and gallium nitrate. Poly anion 3 crystallized as the mixed rubidium/sodium salt Rb2Na2[Ga-4(H2O)(10)(beta-TeW9O33)(2)]center dot 28H(2)O (RbNa-3) in the triclinic space group P (1) over bar with unit cell parameters a = 12.5629(15) angstrom, b = 13.2208(18) angstrom, c = 15.474(2) angstrom, alpha = 80.52(1)degrees, beta = 84.37(1)degrees, and gamma = 65.83(1)degrees All polyanions 1-3 were characterized in the solid state by single-crystal XRD, FT-IR, TGA, and elemental polyanion 2 was also characterized in solution by W-183 NMR and UV vis spectroscopy. Polyanion 2 was used as a homogeneous catalyst toward adenosine triphosphate (ATP) and the DNA model" substrate 4-nitrophenylphosphate, monitored by H-1 and P-31 NMR spectroscopy. The encapsulated gallium(III) centers in 2 promote the Lewis acidic synergistic activation of the hydrolysis of ATP and DNA model substrates at a higher rate in near-physiological conditions. A strong interaction of 2 with the P O bond of ATP was evidenced by changes in chemical shift values and line broadening of the P-31 nucleus in ATP upon addition of the polyanion.