スピン・クロスオーバー・デンドリマー:熱スピン移行の世代数依存の協力性
Tsuyohiko Fujigaya1, Dong-Lin Jiang, Takuzo Aida
1Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Journal of the American Chemical Society
|April 14, 2005
まとめ
トライアゾールユニットを持つデンドリティック協調ポリマーは,熱スピン移行を示します. デンドロン生成数が増加すると,ポリメリゼーションと移行温度が低下しますが,スピン移行の急激さは異なりますが,G1trzFeが最も急激な変化を示しています.
科学分野:
- コーディネーションポリマー化学
- マテリアルサイエンス 材料科学
- 超分子化学とは
背景:
- 焦点トリアゾール単位を持つポリ ((ベンジルエーテル) デンドロンが合成されました.
- これらのデンドロンとの鉄 (II) 複合体は,デンドリート協調ポリマーを形成する.
- これらのポリマーは,熱スピン移行を示します.
研究 の 目的:
- デンドロン生成数の,デンドリット協調ポリマーのスピントランジション特性に対する影響を調査する.
- これらの新材料の構造と熱的振る舞いを特徴づける.
主な方法:
- トリアゾール単位 (Gntrz, n=0-2) を含むポリ (ベンジルエーテル) デンドロンの合成.
- (MeSO3) 2Feと反応して,デンドリート協調ポリマー ([Fe(Gntrz) 3) ((MeSO3) 2.2H2O) を形成する.
- カロリメトリーとX線 difraktionを用いた熱スピン移行の分析.
主要な成果:
- スピン・クロスオーバー温度 (Tc) は,デンドロン生成が増加するにつれて減少した (n=0:335 K,n=1:315 K,n=2:300 K).
- ポリメリゼーションの平均度数は,生成が増加するにつれて減少した (n=0:20,n=1:10,n=2:3).
- G1trzFeは狭い幅 (10K) を示し,G0trzFe (30K) とG2trzFe (50K) はより広い移行を示した.
- X線 difraktionと熱計は,ディスク型の柱状のコア・シェル・アセンブリを明らかにした.
結論:
- デンドリット単位の生成数は,スピン移行温度と協調ポリマーにおけるポリメリゼーションの程度に影響します.
- スピン移行の急激さは,世代番号にのみ依存するものではありません.
- dendritic coordination polymersは,物質科学における潜在的応用を持つ,オーダーされた超分子構造を形成する.
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