Role of Bridging Na+ Cations in the Packing of Na2[Pd(NH3)4]5(W7O24)2·16H2O and Na[Pd(NH3)4]2(HW7O24)·7H2O Structures

Two complex salts with heptatungstate anions and [Pd(NH3)4]2+ and Na+ cations are synthesized. In the structure of Na2[Pd(NH3)]5(W7O24)2·16H2O (a = 11.5703(3) A, b = 12.4653(4) A, c = 14.8201(5) A, α = 69.733(1)°, β = 97.231(1)°, γ = 75.816(1)°, space group P-1, V = 1937.8(1) A3, Z = 1), the Na+ cations link heptatungstate anions into dimers; the Na…O distances are 2.321–2.446 A. In the structure of Na[Pd(NH3)4]2(HW7O24)·7H2O (a = 11.1113(8) A, b = 17.9869(12) A, c = 17.8140(13) A, β = 96.974(2)°, space group P21/n, V = 3533.9(4) A3, Z = 4), the bridging Na+ cations link hydroheptatungstate anions into zigzag chains; the Na…O distances are 2.291–2.724 A.