Ungewöhnliche H-Brückenbindungen in Natriumhydroxidmonohydrat: Röntgen- und Neutronenbeugung an NaOH · H2O bzw. NaOD · D2O

Unusual H-Bonds in Sodium Hydroxide Monohydrate: X-Ray and Neutron Diffraction on NaOH · H₂O and NaOD · D₂O, respectively X-ray data revealed the structure of NaOH · H₂O including the H positions. Neutron diffraction on microcrystalline NaOD · D₂O was used for comparison of H with D positions: The compound crystallizes in a layer-type structure with the sequence …? /O Na O O Na O/ …? closely related to that of hydrargillite Al(OH)₃ with …? /O 2/3 Al O O 2/3 Al O/ …?. Between OH^? ions as acceptors and H₂O molecules mäandric, one-dimensional infinite strong H-bonds occur with d(O…?O) = 2.66 Å and 2.69 Å. These lie within O-layers that coordinate Na⁺ ions. Bridge-bonds between OH^? ions as donors and H₂O molecules as acceptors connect the /O Na O/-layers with d(O…?O) = 3.18 Å.