APTRA-Based Luminescent Lanthanide Complexes Displaying Enhanced Selectivity for Mg2+

作者：Walter Edward R H; Williams J A Gareth^*; Parker David^*

来源：Chemistry - A European Journal, 2018, 24(30): 7724-7733.

DOI：10.1002/chem.201800745

• europium
• luminescence
• magnesium
• sensing
• terbium

A series of three europium(III) complexes has been created in which an APTRA moiety has been integrated into the sensitising chromophore (APTRA=o-aminophenol-N,N,N-triacetate). The constitutionally isomeric complexes EuL1 and EuL2 feature the APTRA unit linked to a metal-bound pyridine ring through an alkynyl unit, differing according to the disposition of the APTRA substituents relative to the CC unit (para-N and para-O). In EuL3, the APTRA ring is directly bonded to the Eu-coordinated pyridine (para-O). The metal binding affinities for magnesium, calcium and zinc ions have been measured by using emission and excitation spectroscopy. The pyridylalkynylaryl systems, EuL1 and EuL2, offer superior affinity and selectivity for Mg2+. The Mg2+ affinities are surprisingly very different from prior studies on structurally related systems that incorporate organic fluorophores as reporters, as opposed to the macrocyclic Eu complex moiety. A much-reduced affinity for calcium and zincpossibly arising from the lower donor ability of the aryl N or O atoms arising from extended conjugationmeans that magnesium ion concentrations can be measured directly in serum for the first time, by using such an approach. An apparent dissociation constant for magnesium binding of K-d=2.4mm was calculated in the serum background.

• 出版日期2018-5-28