title: Organization of lower rim O-alkylated p-phosphonic acid calix[4]arenes.
abstract: Lower rim O-methyl, -n-butyl, and n-octadecyl calix[4]arenes bearing p-phosphonic acid groups on the upper rim have been prepared in high yield, compounds 12-14. Where possible the compounds have been characterized in the solid state using X-ray diffraction, or as the precursor phosphate esters or a cesium salt. The cone conformation ethyl phosphate ester for the octadecyl compound crystallizes in a bi-layer 39.1 A thick which approaches the 40 A of biological membranes. The 1,3-alternate cone conformation of the cesium salt of the O-methyl phosphonic acid has a metal ion coordinated to two methoxy groups, four O-P (two from neighboring calixarenes), and two eta(3)-C(3) moieties from two 1,3-disposed aromatic rings. MALDI-TOF spectra of compounds 12-14 show successive peaks corresponding to 15, 33 and 16 calixarene units, which is consistent with the intra-molecular H-bonding capabilities of the di-protic phosphonic acid groups where the calixarenes are arranged into layers, including bilayers.
authors.affiliation: Centre for Strategic Nano-Fabrication, School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, W.A. 6009, Australia. Department of Chemistry, Washington University, St. Louis, MO 63130, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Clark
authors.forename: Mohamed
authors.initials: M
authors.lastname: Makha
authors.forename: Alexandre N
authors.initials: AN
authors.lastname: Sobolev
authors.forename: Dian
authors.initials: D
authors.lastname: Su
authors.forename: Henry
authors.initials: H
authors.lastname: Rohrs
authors.forename: Michael L
authors.initials: ML
authors.lastname: Gross
authors.forename: Colin L
authors.initials: CL
authors.lastname: Raston