p-フェニレンおよびエチニレン単位から成る形状固有の分子構成要素の柔軟性
Gunnar Jeschke1, Muhammad Sajid, Miriam Schulte
1Laboratory for Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland. gunnar.jeschke@phys.chem.ethz.ch
Journal of the American Chemical Society
|July 2, 2010
まとめ
研究者は,パルス電子パラマグネティック共振 (EPR) を使用して,ナノスケープの分子における脊椎の柔軟性を研究しました. エチニレンおよびp-フェニレン単位を持つオリゴマーは,溶媒特性によって影響される柔軟性においてわずかな違いを示した.
科学分野:
- ポリマー化学のポリマー化学について
- マテリアルサイエンス 材料科学
- ナノテクノロジー ナノテクノロジー
背景:
- エチニレンおよびp-フェニレン単位は,ナノスケープの分子のための重要な構成要素です.
- 脊椎の柔軟性は,分子形状,機械的,電子的性質を決定的に影響する.
- エンドツーエンドの距離分布は,骨幹の柔軟性を特徴づける.
研究 の 目的:
- オリゴ (p-フェニレンエチニレン) とオリゴ (p-フェニレンブタディニレン) の骨幹の柔軟性に関する一貫した粗粒型モデルを開発する.
- 脊髄配列,長さ,スピンラベルの柔軟性に対する影響を調査する.
- オリゴ (p-フェニレンエチニレン) とオリゴ (p-フェニレンブタディニレン) の柔軟性を比較する.
主な方法:
- 異なるp-フェニレン/エチニレン配列と,極性タグを使用したスピンラベルを持つ4つのオリゴーマーセットの合成.
- パルス電子パラマグネティック共振 (EPR) 距離測定は,端から端までの距離分布を決定します.
- 粗粒度モデリングとワームのような鎖と原子模擬との比較.
主要な成果:
- 骨幹の柔軟性に関する一貫した粗粒型モデルが得られた.
- オリゴ ((p-フェニレンブタディニレン) は,オリゴ ((p-フェニレンエチニレン) よりもわずかに高い柔軟性を示した.
- エンドツーエンドの距離分布は,溶媒のガラス化移行温度に依存していることが示された.
結論:
- ハーモニックセグメンテッドチェーンモデルは,バックボーンの柔軟性を正確に記述しています.
- 298 Kでの持続長さは,ポリフェニレンエチニレン (13.8 ± 1.5) nm,ポリフェニレンブタディニレン (11.8 ± 1.5) nmと予測されました.
- 柔軟性は,広範囲の温度範囲で調和曲折モデルと定量的に一致しています.
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