at Google ScholarTitle data
Butterhof, Christian ; Bärwinkel, Kilian ; Senker, Jürgen ; Breu, Josef:
Polymorphism in co-crystals: a metastable form of the ionic co-crystal 2 HBz·1 NaBz crystallised by flash evaporation.
In: CrystEngComm.
Vol. 14
(2012)
Issue 20
.
- pp. 6744-6749.
ISSN 1466-8033
DOI: https://doi.org/10.1039/C2CE25562F
Abstract in another language
While polymorphism is a wide spread phenomenon, the number of reported polymorphic co-crystals is still very limited. Here we report the synthesis and structural characterisation of such a rare case of polymorphism with a co-crystal of benzoic acid (HBz) and sodium benzoate (NaBz). Flash evaporation yielded a new polymorph of this ionic co-crystal with a stoichiometry of 2 HBz·1 NaBz. The thermodynamic relationship between the known and the new polymorph was determined to be of enantiotropic nature. At room temperature, this new form B is metastable. While the known form A is composed of one dimensional tapes, form B is built from infinite rods. The coordination sphere of sodium, however, in both forms is octahedral and the packing around it is dense.