TY - JOUR
T1 - Achiral metastable crystals of sodium chlorate forming prior to chiral crystals in solution growth
AU - Niinomi, Hiromasa
AU - Yamazaki, Tomoya
AU - Harada, Shunta
AU - Ujihara, Toru
AU - Miura, Hitoshi
AU - Kimura, Yuki
AU - Kuribayashi, Takahiro
AU - Uwaha, Makio
AU - Tsukamoto, Katsuo
PY - 2013/12/4
Y1 - 2013/12/4
N2 - Chiral symmetry breaking in NaClO3 crystallization from an aqueous solution with perturbations has been of great interest. To understand the mechanism, several models focusing on the early stage of the crystallization have been proposed. However, they are ambiguous because the early stage has been barely explored directly. Here, we investigate the early stages of the crystallization process driven by droplet evaporation using a combination of direct in situ microscopic observations and cryogenic single-crystal XRD experiments. We demonstrate that an achiral crystal having P21/a symmetry, which is newly discovered for a solution growth, first appears in the droplet and then transforms into the chiral crystals. Additionally, determination of the lattice constants by XRD experiments (a = 8.42 Å, b = 5.26 Å, c = 6.70 Å, β = 109.71) revealed that the achiral phase should be identical to Phase III (a = 8.78 Å, b = 5.17 Å, c = 6.83 Å, β = 110), which is a high-temperature phase from a melt growth of NaClO3. We advocate further assessment of the achiral crystal and a new pathway for the formation of chiral crystals via crystalline phase transition from achiral Phase III.
AB - Chiral symmetry breaking in NaClO3 crystallization from an aqueous solution with perturbations has been of great interest. To understand the mechanism, several models focusing on the early stage of the crystallization have been proposed. However, they are ambiguous because the early stage has been barely explored directly. Here, we investigate the early stages of the crystallization process driven by droplet evaporation using a combination of direct in situ microscopic observations and cryogenic single-crystal XRD experiments. We demonstrate that an achiral crystal having P21/a symmetry, which is newly discovered for a solution growth, first appears in the droplet and then transforms into the chiral crystals. Additionally, determination of the lattice constants by XRD experiments (a = 8.42 Å, b = 5.26 Å, c = 6.70 Å, β = 109.71) revealed that the achiral phase should be identical to Phase III (a = 8.78 Å, b = 5.17 Å, c = 6.83 Å, β = 110), which is a high-temperature phase from a melt growth of NaClO3. We advocate further assessment of the achiral crystal and a new pathway for the formation of chiral crystals via crystalline phase transition from achiral Phase III.
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U2 - 10.1021/cg401324f
DO - 10.1021/cg401324f
M3 - Article
AN - SCOPUS:84889835204
VL - 13
SP - 5188
EP - 5192
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 12
ER -