Complexation of higher fullerenes by calix[5]arene-based host molecules.
The binding abilities of calix[5]arene-based host molecules for higher fullerenes (C76, C78, and C84) were investigated in organic solvents. The binding abilities of double-calix[5]arenes to higher fullerenes are high. In particular, their association constants to C76 and C78 in toluene reached at the order of 10(5) M(-1). In contrast, the binding abilities of simple calix[5]arenes decreased as increasing the size of the fullerenes. Accordingly, linking two calix[5]arenes with the covalent bonds creates the large cavities, complementary to higher fullerenes. The structure of the host-guest complex of double-calix[5]arene and C76 was discussed. The carbons of the polar end of C76 characteristically shifted upfield more than the other carbons in the host-guest complex, indicating that these polar carbons reside most deeply inside the cavity of the calix[5]arene.
Haino
Takeharu
T
Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama Higashi-Hiroshima 739-8526, Japan.
Fukunaga
Chigusa
C
Fukazawa
Yoshimasa
Y
D047250:Calixarenes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods; D037741:Fullerenes / Q000737:chemistry*; D007700:Kinetics; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008968:Molecular Conformation; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D013053:Spectrophotometry; D013237:Stereoisomerism; D013696:Temperature
D037741:Fullerenes; D046911:Macromolecular Substances; D012997:Solvents; D047250:Calixarenes; D002244:Carbon