日本語AIでPubMedを検索
低温及び高温条件下でのL-アスパラギン一水和物に対するFe(III)の影響を調べた
Effect of Fe (III) on L-asparagine monohydrate investigated under low- and high-temperature conditions.
PMID: 32682278 DOI: 10.1016/j.saa.2020.118643.
抄録
鉄ドープL-アスパラギン一水和物(LAM:Fe)結晶のラマンスペクトルを17Kから490Kまでの温度変化下で調べた。振動スペクトルを用いて、温度変化における結晶の安定性に及ぼすFe(III)イオンの影響について議論した。分子間及び分子内振動モードの振る舞いから、2つの相転移とアモルファス相転移を示唆した。これらの効果は、ラマンデータを非常によく裏付ける粉末X線回折測定によっても明らかになった。さらに、すべての相の格子定数を決定し、低温では結晶は構造転移を起こし、高温では斜方晶(P222空間群)から単斜晶(P2空間群)へと構造が変化し、分解が始まるためにアモルファス相へと変化することを確認した。最後に、微分走査熱量分析を用いてLAM:Feの構造安定性を調べた結果、ラマン及びX線回折データとよく一致した。
Raman spectra of Fe-doped L-asparagine monohydrate (LAM:Fe) crystal were studied under several temperatures varying from 17 to 490 K. The effect of Fe (III) ion on the stability of the crystal in changing temperature through the vibrational spectra was discussed. The behavior of inter and intra-molecular vibration modes has indicated two phase transitions and an amorphous transformation. These effects were also clarified by X-ray powder diffraction measurements which corroborate very well the Raman data. In addition, we have determinated the lattice parameters of all phases and verified that under low temperature conditions the crystal undergoes a conformational transition whereas under high temperatures its structure transforms from the orthorhombic (P222-space group) to the monoclinic (P2-space group) symmetry and, after this process, it goes to an amorphous phase due to the start of the decomposition. Finally, differential scanning calorimetry analysis was utilized as complementary technique to investigate the structural stability of LAM:Fe and results are in a good agreement with the Raman and the X-ray diffraction data.
Copyright © 2020 Elsevier B.V. All rights reserved.