6874
J. Phys. Chem. B 1997, 101, 6874-6878
Electrochemiluminescence from Calixarene-Coated Porous Si Liquid Junction Cells Libing Zhang and Jeffery L. Coffer* Department of Chemistry, Texas Christian UniVersity, Fort Worth, Texas 76129 ReceiVed: February 28, 1997; In Final Form: May 24, 1997X
In this paper, the electrochemiluminescence (ECL) of calixarene carboxylic acid coated porous Si (PS) is reported. Electrochemiluminescence is observed from the anodic oxidation of calixarene-coated porous Si in an electrolyte containing 1.0 M H2SO4. These calixarene carboxylic acid derivatives coated onto the porous Si surface affect both the duration and efficiency of the light emission. Electrochemiluminescence can be generated for longer periods of time for these coated porous Si junctions relative to untreated porous Si, ranging from up to 3 h for calix[4]arene-coated porous Si to about 50 min for the calix[n]arene (n ) 5, 7, 8) derivatives. This improved duration of electrochemiluminescence comes at the cost of quantum efficiency; for calix[8]arene-coated PS it is 0.0015%, while for calix[4]arene-coated porous Si,
