Supplementary Material for Organic & Biomolecular Chemistry This journal is ' The Royal Society of Chemistry 2005 1 Electronic supplementary information Thiacalix[4]arene derivatives as radium ionophores: a study on the requirements for 226 Ra 2+ extraction Fijs W. B. van Leeuwen, Hans Beijleveld, Aldrik H. Velders, Jurriaan Huskens, Willem Verboom, and David N. Reinhoudt Contents 1 2D 1 H NMR spectra 2 - Compound 2 (Figure S1) 2 - Compound 5 (Figure S2) 3 - Compound 7 (Figure S3) 4 - Complex [Ba(5)Pic] (Figure S4) 5 Extraction equilibria and stoichiometries used to obtain extraction constants 5 - Singly charged ionophores, 1: 1 stoichiometry (2 and 5) 6 Extraction curves M 2+ cations (Figure S5) 7 - Di- or trivalently charged ionophores, 1: 1 stoichiometry - (3a,b, 4a,b, 6, and 7) 9 Extraction curves M 2+ cations (Figure S6) 9 Extraction curves 226 Ra 2+ cations (Figure S7) 10 - Tetravalent charged ionophore, 1: 2 stoichiometry (8) 11 Extraction curves M 2+ cations (Figure S8) 11 Extraction curves 226 Ra 2+ cations (Figure S9) 14 References 14