Synthesis and spectroscopic properties of new luminol-linked calixarene derivatives

Syntheses of luminol-linked calixarene derivatives, p-(2,3-dihydro-1,4-phthalazinedione-5-azo)calix[n]arenes (n=4, 6, 8: (3a), (3b) and (3c), respectively), are described together with their spectroscopic properties for analytical purposes. It is found that the synthesized derivatives have a good solubility in basic aqueous media and possess multi-optical functions. In alkaline media of pH 11.5 containing 10 μg ml−1 of Cu(II), the calixarenes react with H2O2 to emit light of wavelength 420 nm. Various parameters such as acidity, order and amounts of reagent addition for H2O2 chemiluminescent determination are optimized. Among these calixarenes, (3a) is the most sensitive one with a detection limit of 0.01 μg ml−1 H2O2, and its chemiluminescence intensity is directly proportional to the concentration of H2O2 in the range 0.01–5 μg ml−1. Additionally, the calixarenes fluorescence properties similar to that of luminol do not seem important because of not causing any great spectral change upon addition of H2O2, Ag+, Co2+, Cr3+, Cu2+ or Fe2+, but the absorption spectrum of (3a) gives a specific response to Ag+, making it of potential use as a chromogenic reagent for Ag+ detection.