塩で良い:中性pHでの水性環開きメタテシスポリメリゼーション
Jeffrey C Foster1, Marcus C Grocott1, Lucy A Arkinstall1
1School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Journal of the American Chemical Society
|July 17, 2020
まとめ
水性環開きメタテシスポリメリゼーション (ROMP) は,ルテニウム触媒を無効化するクロライドイオンに敏感です. 塩化塩を加えると,モノメアの変換と制御が促進され,水中の二ブロック共ポリマー合成が可能になる.
科学分野:
- ポリマー化学
- 緑の化学
- 材料科学
背景:
- 水性環開きメタテシスポリメリゼーション (ROMP) は,環境に優しいポリマー合成を提供します.
- 水溶性ルテニウム触媒は,クロスメタテシス (CM) とリングクロージングメタテシス (RCM) で知られているが,その水中のROMP性能はあまり理解されていない.
- 水性ROMPにおける触媒の振る舞いを理解することは,バイオマクロ分子機能化やナノ粒子調製などのアプリケーションに不可欠です.
研究 の 目的:
- pH,塩添加物,および触媒の負荷が水中のROMPに与える影響を調査する.
- 水中のROMPで触媒の無効化の原因を判断する.
- 効率的な水性ROMPとコポリマー合成のための条件を最適化します.
主な方法:
- 異なるpH,塩化物濃度,および触媒負荷下で水中のROMPを研究した.
- 触媒の無効化メカニズムを分析し,Ru- ((OH)) 複合体の形成を提案した.
- ROMP誘発セルフアセンブリ (ROMPISA) を使って合成された二ブロック共ポリマー.
主要な成果:
- 水中のROMPは塩化物の濃度に対して敏感であり,低濃度では単体変換と触媒の寿命が短縮される.
- ルテニウム中心の水酸化物または水による塩化物リガンドの移位は,触媒の無効化を引き起こす.
- 塩化物塩 (NaCl,KCl,テトラブチアモニウム塩化物) を加えることで,ROMPの変換と制御が著しく改善された.
- ディブロック共ポリマーがROMPISAで90%の水で1モル%の触媒で成功して合成されました.
結論:
- 塩素イオンは,水中のROMPにおけるルテニウム触媒の安定化に不可欠である.
- 最適な水性ROMP条件により,ポリマーとコポリマーの効率的な合成が可能になります.
- 中性pHの水性ROMPは,生物学的介質での応用のための新しい可能性を開きます.
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