Synthesis and Properties of Endohedral Aza[60]fullerenes: H2O@C59N and H2@C59N as Their Dimers and Monomers

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• 作者：Yoshifumi Hashikawa ; Michihisa Murata ; Atsushi Wakamiya ; Yasujiro Murata
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：March 30, 2016
• 年：2016
• 卷：138
• 期：12
• 页码：4096-4104
• 全文大小：639K
• ISSN：1520-5126

文摘

The macroscopic-scale syntheses of the first endohedral aza[60]fullerenes X@C₅₉N (X = H₂O, H₂) were achieved in two different ways: (1) synthesis from endohedral fullerene H₂O@C₆₀ as a starting material and (2) molecular surgical synthesis from a C₅₉N precursor having a considerably small opening. In the neutral state of H₂O@C₅₉N, we expected the H-bonding interaction or repulsive N–O interaction between entrapped H₂O and a nitrogen atom on the C₅₉N cage. However, an attractive electrostatic N–O interaction was suggested from the results of variable temperature NMR, nuclear magnetic relaxation times (T₁, T₂), and density functional theory (DFT) calculations. Upon the reaction with acetone via cationic intermediate C₅₉N⁺, we found a difference in reaction rates between H₂O@C₅₉N and H₂@C₅₉N dimers (observed reaction rates: k′(H₂O)/k′(H₂) = 1.74 ± 0.16). The DFT calculations showed thermal stabilization of C₅₉N⁺ by entrapped H₂O through the electrostatic interaction.