title: UV-Vis, fluorescence and NMR spectroscopic investigations on inclusion properties of a designed tetrahomocalix[8]arene with fullerenes C60 and C70 in solution.
abstract: The present article reports the spectroscopic investigations on non-covalent interaction of fullerenes C(60) and C(70) with a macrocyclic receptor molecule, namely, 1,3,5,7-tetrahomo-p-tert-butylcalix[8]arene (1) in toluene. Jobs method of continuous variation reveals 1:1 stoichiometry for the fullerene complexes of 1. The most fascinating feature of the present study is that 1 binds selectively C(60) compared to C(70) as obtained from binding constant (K) data of C(60)-1 (K(C60-1)) and C(70)-1 (K(C70-1)) complexes which are enumerated to be 265,000 dm(3) mol(-1) and 63,43 dm(3) mol(-1), respectively, and selectivity in binding (K(C60-1)/K(C70-1)) is estimated to be 4.18 as obtained from UV-Vis study. Steady state fluorescence studies reveal quenching of fluorescence of 1 in presence of fullerenes and the K value of the C(60)-1 and C(70)-1 complexes are estimated to be 80,760 and 68,780 dm(3) mol(-1), respectively, with selectivity in binding (K(C60-1)/K(C70-1)) ~1.18. (1)H NMR analysis provides very good support in favor of strong binding between C(60) and 1. The high value of K value for C(60)-1 complex indicates that 1 forms an inclusion complex with C(60).
authors.affiliation: Department of Chemistry, The University of Burdwan, Golapbag, Burdwan, India.
authors.forename: Amal
authors.initials: A
authors.lastname: Halder
authors.forename: Suchitra
authors.initials: S
authors.lastname: Bhatt
authors.forename: Sandip K
authors.initials: SK
authors.lastname: Nayak
authors.forename: Subrata
authors.initials: S
authors.lastname: Chattopadhyay
authors.forename: Sumanta
authors.initials: S
authors.lastname: Bhattacharya
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014050:Toluene / Q000737:chemistry
chemical_list: D037741:Fullerenes; D012996:Solutions; C069836:fullerene C70; D047250:Calixarenes; D014050:Toluene; C069837:fullerene C60