E-Locus - Institutional Repository of the University of Crete

Home Search

Results - Details

Search command : Author="Κατερινόπουλος" And Author="Χαράλαμπος"

Current Record: 69 of 79

[Add to Basket]

Identifier

000346220

Title

Οργανική σύνθεση νέων αζα-μακροκυκλικών και φαινανθρολινικών φθορισμομετρικών δεικτών ενισχυμένης μεταλλοδεσμευτικής ικανότητας τοξικών μεταλλοϊόντων και υψηλής κβαντικής απόδοσης

Alternative Title

Synthesis of new aza-macrocyclic phenanthrolinic fluorescent probes with enhanced affinity for toxic cations and high quantum yield

Author

Βουτσαδάκη, Στυλιανή Μάρκου

Thesis advisor

Κατερινόπουλος, Χαράλαμπος Ε

Abstract

In this thesis, the synthesis and the fluorescence profile of a series of potential fluorescent heavy metal ion probes is described. All seven probes incorporate in their structure the coumarin moiety as fluorophore. For the first three probes, the 1-aza-15-crown-5 moiety, for the next two, the picolylamine, whereas for the last two ones, the 1,4,8,11-tetraazatetradecane (cyclam) group were chosen as ionophores. The fluorescence response of these probes to increasing concentrations of Zn²⁺, Cd²⁺, Hg²⁺ and Pb²⁺ ions is described in the next section. The monoazacrown ether probes where the ionophore and fluorophore are bridged with a methylene group, respond to increasing concentrations of Zn²⁺ and Cd²⁺ ions. The former exhibits weaker binding to Zn²⁺ ions with a dissociation constant Κ_d = 8.7 μΜ and stronger binding for Cd²⁺ ions (Κd = 16 nΜ). These Kd values imply that the compound may used as a cadmium ions sensor in the presence of higher levels of zinc ions. The probe where the ionophore, 1-aza-15-crown-5, is coupled with the fluorophore (a 7-(4-methyl)coumarin analog) through a carbamide linker, has a strong response to Hg²⁺ ions. Its K_d was calculated as low as 13.14 μM. The tri-BOC-cyclam analog of compound mentioned before, is also an efficient mercury ion sensor with a calculated Κ_d = 35.48 μM. The indicator, where the bis-(2-picolyl)amine ionophore is linked to 7-(4-methyl)coumarin with a carbamide spacer, responds to nanomolar levels of cadmium ions and to milimolar levels of lead ions. Ion competition studies indicate that the probe is Pb²⁺-selective however, the mode of its response to increasing Pb²⁺ concentrations does not allow for the calculation of an accurate K_dvalue. The 2-picolyl analog, with the ionophore directly connected to 7-amino-(4-methyl)coumarin, is in turn, zinc-selective with a Κ_d = 25.17 μΜ. Finally a series of synthetic studies, aiming to incorporate the 5-amino-1,10-phenanthroline moiety as the probes’ fluorophore, led to the conclusion that, due to electronic factors, this heteroaromatic compound is not a suitable synthon for the construction of heavy metal ion fluorescent probes.

Language

Greek

Subject

1,4,8,11- tetraazacyclotetradecane

1-aza-15-crown-5

10-phenanthroline

10-φαινανθρολίνη

5-amino-1

5-αμινο-1

Bis-(2-picolyl)amine

Cadmium

Cd2+