# Supplementary Material (ESI) for Chemical Communications # This journal is © The Royal Society of Chemistry 2005 1 Recognition of Quaternary Ammonium Cations by Calix[4]Arene Derivatives Supported on Gold Nanoparticles Arturo Arduini, Domenico Demuru, Andrea Pochini* and Andrea Secchi Dipartimento di Chimica Organica e Industriale, Parco Area delle Scienze 17/a, I-43100 Parma, Italy. Fax: +39 0521 905472; Tel: +39 0521 905408; E-mail: andrea.pochini@unipr.it General Information. All reactions were carried out under nitrogen; all solvents were freshly distilled under nitrogen and stored over molecular sieves for at least 3h prior to use. All other reagents were of reagent grade quality as obtained from commercial suppliers and were used without further purification. Column chromatography were performed on silica gel 63-200 mesh. NMR spectra were recorded in CDCl 3 unless otherwise indicated. 25,27-bis(hex-5-enyloxy)-26,28-dihydroxy-calix[4]arene (3a), and 25,27- bis(undec-10-enyloxy)-26,28-dihydroxy-calix[4]arene (3b) General procedure: a mixture of calix[4]arene 1 (3.0 g, 7.0 mmol), K 2 CO 3 (2.9 g, 21.0 mmol), KI (catalytic) and the appropriate tosylate 2a,b (21.0 mmol) in CH 3 CN (150 ml) was stirred and heated under reflux for five days. The solvent was then evaporated under vacuum and the residue taken up with CH 2 Cl 2 . The organic phase was washed with water up to neutrality and dried over anhydrous Na 2 SO 4 . After complete evaporation of the solvent, the resulting crude product was purified by column chromatography (silica gel, hexane 9 : ethyl acetate 1). Compound 3a is a known compound, the spectral data are in agreement to those found in the literature: 1 MS(CI) (m/z): 589 (MH + ). m.p.: 110-111 °C. Compound 3b: yellowish solid (65% yield); 1 H NMR (CDCl 3 , 300 MHz, ppm): δ 1.34-1.48(20H, m), 1.67-1.72(4H, m), 2.01-2.09(8H, m), 3.37(4H, J=14 Hz, d), 3.99(4H, J=14 Hz, t), 4.32(4H, J=14 Hz, d), 4.91-5.02(4H, m), 5.75-5.85(2H, m),