Two polyoxometalate open framework (POMOF) materials have been synthesized using a secondary building unit (SBU) approach that facilitates the convergent assembly of multidimensional framework materials using a preassembled anionic SBU {P8W48}, with integrated “pore” 1 nm in diameter, and electrophilic manganese {Mn2+} linkers. This yields two new POMOFS with augmented hexagonal tiling (2 and 3), related to a known three-dimensional (3D) cubic array K18Li6[MnII8(H2O)48P8W48O184]·108H2O (1), K12[MnII14(H2O)30P8W48O184]·111H2O (2), and K8Li4[MnII14(H2O)26P8W48O184]·105H2O (3). These frameworks have been crystallized from aqueous Li-buffered solutions of {P8W48} and MnII(ClO4)2·6H2O via careful control of the synthetic strategy akin to a crystal engineering approach using cation and temperature control to isolate different material architectures shown by compounds 1−3.