The Preparation Of Novel Porphyrin Deriviatives And Their Application As Molecular Recognition Carriers

There has been considerable interest in studying chemical sensors because they can be applied to a wide range of analytical tasks, such as clinical diagnosis, bioassay, environmental monitoring, etc. So far, the development of practical sensors with high sensitivity and good selectivity is still a challenge. Porphyrins are recognized as perfect host for molecular recognition owing to their diversity, their rigid molecular structures, the position and direction of the substituents on the porphyrin ring being controllable. The study of the chemical sensing characteristics of porphyrins is an active area all the while. Searching for novel porphyrin derivatives with high selectivity as the molecular recognition ionophores for chemical sensors still remains task of theoretical and practical significance.The contents of the thesis are presented as follows:1. The synthesis of a new compound, amide-linked diporphyrin xanthene(ADPX), and its application for preparation of lead(II) ion selective electrodes was described. And the composition of the electrode membrane has been optimized and excellent response performance was achieved. Moreover, the effect of pH and selectivity of the electrode was studied. And the sensor was applied as indicator electrode in titration of Pb(II) with potassium chromate solution with satisfied results.2. The synthesis of a new compound, amide-linked diporphyrin xanthene(ADPX), and its application for preparation of thiocyanate selective electrodes was described. And the composition of the electrode membrane has been optimized and excellent response performance was achieved. Moreover, the effect of pH and selectivity of the electrode was studied. The electrode was applied to the determination of SCN- in body urine with satisfactory results.3. A porphyrin derivative (fluorophore) appended with bipyridine (ionophore) has been first applied for preparation of a Cu(II)–sensitive optical chemical sensor, which is based on fluorescence quenching of zinc-porphyrin by the electron transfer process. The sensor exhibits a linear response toward Cu(II) in the concentration range 3.2×10^-7–1.0×10^-5 M with a high selectivity.