Terbium luminescence in Langmuir-Blodgett films of octafunctionalized calix[4] resorcinarenes

Calix[4]resorcinarenes functionalized with pendant a acetates or alpha-(diethyl acetamides) [(n-C11H23)(4)-C[4]R-(OCH2COX)(8); 1, X = OMe; 2, X = NEt2] have been shown to incorporate terbium(III) ions into Langmuir-Blodgett films. Energy-transfer luminescence from a single monolayer on quartz has been demonstrated. An excitation wavelength of 280 nm, corresponding to the chromophore of the ligands aromatic rings, was used. Emission was observed at 489, 545.5, 586, and 620 nm, corresponding to the known transitions of terbium (D-5(4) --> F-7(6), D-5(4) --> F-7(5), D-5(4) --> F-7(4), and D-5(4) --> F-7(3), respectively). It was demonstrated that a multilayer LB film of 1 and a monolayer film of 2 readily abstract terbium(III) from 2 x 10(-4) M aqueous solutions of TbCl3 and that energy transfer luminescence was subsequently exhibited.