Yoshida K, Osuka A. β,β-(1,4-Dithiino)subporphyrin Dimers Capturing Fullerenes with Large Association Constants.
Chemistry 2016;
22:9396-403. [PMID:
27238619 DOI:
10.1002/chem.201601152]
[Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Indexed: 11/07/2022]
Abstract
β,β-(1,4-Dithiino)subporphyrin dimers 7-syn and 7-anti were synthesized by the nucleophilic aromatic substitution reaction of 2-bromo-3-(4-methoxyphenylsulfonyl)subporphyrin 4 with 2,3-dimercaptosubporphyrin 5 under basic conditions followed by axial arylation. Additions of C60 or C70 to a dilute solution of 7-anti (ca. 10(-6) m) in toluene did not cause appreciable UV/Vis spectral changes, while similar additions to a concentrated solution (ca. 10(-3) m) resulted in precipitation of complexes. In contrast, dimer 7-syn captured C60 and C70 in different complexation stoichiometries in toluene; a 1:1 manner and a 2:1 manner, respectively, with large association constants; Ka =(1.9±0.2)×10(6) m(-1) for C60 @7-syn, and K1 =(1.6±0.5)×10(6) and K2 =(1.8±0.9)×10(5) m(-1) for C70 @(7-syn)2 . These association constants are the largest for fullerenes-capture by bowl-shaped molecules reported so far. The structures of C60 @7-anti, C70 @7-anti, C60 @7-syn, and C70 @7-syn have been determined by single-crystal X-ray diffraction analysis.
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