Frozen 1,3-alternate conformation of exhaustively methylated azacalix[4]arene in solution: Successful immobilization by small but yet sufficiently bulky O-methyl group

Chemistry Letters

Volumn 36, Issue 11, 2007, Pages 1374-1375

  Tsue, Hirohito ^a   Ishibashi, Koichi ^a   Tokita, Satoshi ^a   Matsui, Kazuhiro ^a   Takahashi, Hiroki ^a   Tamura, Rui ^a  

^a KYOTO UNIVERSITY   (Japan)

Author keywords

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Indexed keywords

EID: 36849021506     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2007.1374     Document Type: Article

References (21)

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19. The deviation of the estimated T¡ values is less than 5%.
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21. To evaluate electronic effect, NBO analysis at a B3LYP/6-31+G(d,p)// B3LYP/6-31+G(d,p) level was performed. It was found that ca. 0.24 electrons of each nitrogen lone pair migrated equally to the two adjacent benzene rings. In other words, the bridging nitrogen atoms partially conjugate with the benzene rings, suggesting that electronic effect also contributes to the stabilization of the 1,3-conformation of 1.