Supplementary information 1 Supplementary Information p-tert-Butylcalix[6]arene hexacarboxylic acid conformational switching and octahedral coordination with Pb(II) and Sr(II) Birendra Babu Adhikari, a,b Keisuke Ohto b and Michael P. Schramm* a a Department of Chemistry and Biochemistry, California State University, Long Beach 1250 Bellflower Blvd., Long Beach, 90840, CA, USA; Fax: (+)1-562-985-8557; E-mail: michael.schramm@csulb.edu b Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, 1-Honjo, 840-8502, Saga, Japan Table of contents General Information .......................................................................................................................................2 Figure SI1. 1H NMR spectra of 3 in different solvents. ................................................................................4 Figure SI2. 300 MHz 1 H NMR spectra of 3 in presence of 0.5 equivalent Pb(II) at the time of mixing.......5 Figure SI3. 300 MHz 1 H NMR spectra of 3 in presence of 1.0 equivalent Pb(II) at the time of mixing.......6 Figure SI4. 300 MHz 1 H NMR spectrum of 3·Pb(II) complex after 26 hours ...............................................7 Figure SI5. 300 MHz 1 H NMR spectrum of 3·Pb(II) complex after 15 days. ...............................................8 Figure SI6. 300 MHz 1 H NMR from titration of TBC[6]CH 2 COOMe (2b) with Pb(II) ..............................9 Figure SI7. 300 MHz 1 H NMR spectrum of 3·Pb(II) complex at 253 K and 333 K. ...................................10 Figure SI8. 75 MHz 13 C NMR spectrum of equilibrium sample of 3·Pb(II) complex. ...............................11 Figure SI9. 75 MHz DEPT-135 spectrum of equilibrium sample of 3·Pb(II) complex. .............................11 Figure SI10. 300 MHz 1 H NMR spectra of 3·Pb(II) complex at equilibrium..............................................12 Figure SI11. 300 MHz COSY data of equilibrium sample of 3 in presence of 1.0 equivalent Pb(ClO 4 ) 2 •3H 2 O in CDCl 3 /CD 3 CN (1/1). ....................................................................................................13 Figure SI12. 300 MHz NOESY data of equilibrium sample of 3 in presence of 1.0 equivalent Pb(ClO 4 ) 2 •3H 2 O in CDCl 3 /CD 3 CN (1/1). ....................................................................................................14 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2014