| Abstract: | Synthesis and Structure of New Sodium Hydrogen Sulfates Na(H3O)(HSO4)2, Na2(HSO4)2(H2SO4), and Na(HSO4)(H2SO4)2 Three acidic sodium sulfates have been synthesized from the system sodium sulfate/sulfuric acid and have been crystallographically characterized. Na(H3O)(HSO4)2 ( A ) crystallizes in the space group P21/c with the unit cell parameters a = 6.974(2), b = 13.086(2), c = 8.080(3) Å, α = 105.90(4)°, V = 709.1 Å3, Z = 4. Na2(HSO4)2(H2SO4) ( B ) is orthorhombic (space group Pna21) with the unit cell parameters a = 9.970(2), b = 6.951(1), c = 13.949(3) Å, V = 966.7 Å3 and Z = 4. Na(HSO4)(H2SO4)2 ( C ) crystallizes in the triclinic space group P1 with the unit cell parameters a = 5.084(1), b = 8.746(1), c = 11.765(3) Å, α = 68.86(2)°, β = 88.44(2)°, γ = 88.97(2)°, V = 487.8 Å3 and Z = 2. All three compounds contain SO4 tetrahedra as HSO4? anions and additionally in B and C in form of H2SO4 molecules. The ratio H:SO4 determines the connectivity degree in the hydrogen bond system. In A , there are zigzag chains and dimers additionally connected via oxonium ions. Complex chains consisting of cyclic trimers (two HSO4? and one H2SO4) are present in B . In structure C , several parallel chains are connected to columns due to the greater content of H2SO4. Sodium cations show a distorted octahedral coordination by oxygen in all three structures, the NaO6 octahedra being “isolated” (connected via SO4 tetrahedra only) in A . Pairs of octahedra with common edge form Na2O10 dimeric units in C . Such double octahedra are connected via common corners forming zigzag chains in B . |
