From 3D channelled frameworks to 2D layered structures in molecular salts of l-serine and dl-serine with oxalic acid

Abstract

L-Serine and DL-serine have been treated with oxalic acid under different experimental conditions, e.g. crystallization from solution and slurry, kneading and dry mixing, yielding the molecular salts [L-serH]₂[ox]·2H₂O forms I and II, [L-serH][Hox] and [DL-serH]₂[ox]·2H₂O, all fully characterized by powder or single crystal X-ray diffractions; the relationship between the different crystal forms, relative thermal stability, dependence on relative humidity and possible interconversions have all been explored.