title: Synthesis and specific fluoride binding properties of expanded dithiacalixphyrins.
abstract: Expanded dithiacalixphyrins with the N(2)S(2) core containing two sp(3) and three sp(2) meso-carbons have been prepared by condensation of one equivalent of butene-2,3-diyl-bisthiophene-2,5-diyl-bis(p-methoxyphenylmethanol) with one equivalent of 5,5'-dialkyldipyrromethane under mild acid catalyzed conditions in decent yields. The expanded dithiacalixphyrins were characterized by HR-MS, 1D and 2D NMR techniques and the structure of one of the expanded dithiacalixphyrin macrocycles was solved by X-ray crystallography. The crystal structure analysis indicated that the macrocycle is highly distorted and attains a boat shaped structure. The expanded thiacalixphyrins showed a specific sensing ability for F(-) ions over other anions as judged from absorption, NMR and mass spectral studies.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Powai, Mumbai 400076, India. ravikanth@chem.iitb.ac.in.
authors.forename: Emandi
authors.initials: E
authors.lastname: Ganapathi
authors.forename: Tamal
authors.initials: T
authors.lastname: Chatterjee
authors.forename: Mangalampalli
authors.initials: M
authors.lastname: Ravikanth