title: p-tert-Butylcalix[6]arene hexacarboxylic acid conformational switching and octahedral coordination with Pb(II) and Sr(II).
abstract: p-tert-Butylcalix[6]arene hexaacetic acid is in a symmetric cone conformation in CHCl3, but it becomes conformationally flexible in CHCl3/CH3CN (1 : 1). In this mixture the host has a strong binding affinity towards Pb(II) and instantly forms a complex of low symmetry--shortly thereafter structural reorganization occurs resulting in a high symmetry complex of Pb(II) in an octahedral cage of carboxylates. Sr(II) and Ba(II) display similar behavior over a longer period of time.
authors.affiliation: Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, 90840, CA, USA. michael.schramm@csulb.edu.
authors.forename: Birendra Babu
authors.initials: BB
authors.lastname: Adhikari
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ohto
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schramm