Solution NMR studies of supramolecular complexes of [60]- and [70]fullerenes with mono O-substituted calix[6]arene.
Supramolecular complexation of [60]- and [70]fullerenes with 37-allyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert butyl)calix[6]arene (I) has been studied in CCl(4) medium by NMR spectrometric method. All of the complexes are found to be stable with 1:1 stoichiometry. Formation constants (K) of the above supramolecular complexes have been determined from systematic variation of NMR chemical shifts of specific protons of I in the presence of [60]- and [70]fullerenes. Trends in the K value suggest that [70]fullerene binds more strongly with I relative to [60]fullerene. Both PM3 and ab initio calculations reveal that the intermolecular interaction in the [70]fullerene/I complex proceeds through quite deep energy minima.
Bhattacharya
Sumanta
S
Department of Chemistry, The University of Burdwan, Golapbag, Burdwan 713 104, India. sum_9974@rediffmail.com
Chattopadhyay
Subrata
S
Nayak
Sandip K
SK
Banerjee
Manas
M
D047250:Calixarenes / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry*; D012996:Solutions
D037741:Fullerenes; D010636:Phenols; D012996:Solutions; C476540:calix(6)arene; C069836:fullerene C70; D047250:Calixarenes; C069837:fullerene C60