A cyclam-type “turn on” fluorescent sensor selective for mercury ions in aqueous media

Influence of Introduced Substituents on the Anion-selectivity of [14]Tetraazaannulene Complexes

“…Concerning the anion-selectivities of 1 and 4, the incorporation of naphthalene rings into the azaannulene framework decreased not only the interference of the ClO4 -ion but also the I -ion-selectivity over the SCN -ion. Comparison studies between the dibenzotetraaza [14]annulene nickel complexes 1 -3 indicated that differences in the attached substituents of the [14]tetraazaannulene nickel complexes greatly influenced the ion-selectivity as ionophores. According to our computational results, the ionophoric properties of [14]tetraazaannulene nickel complexes 1 -4 were influenced by their electrostatic properties rather than their topological properties.…”

“…23,24 In general, anion-selective ISEs exhibit roughly the same selectivity sequence with preference of lipophilic anions and rejection of hydrophilic anions (Hofmeister lyotropic anion selectivity sequence). 27 Therefore, ISEs based on Co(II) and Ni(II) complexes of a cyclam with three n-octyl groups are attractive due to their I Nickel(II) complexes of [14]tetraazaannulene derivatives incorporating aromatic rings into their azaannulene framework were synthesized, and the anion-selectivity of the [14]tetraazaannulene nickel complexes 1 -4 was evaluated by potentiometric measurements with solvent polymeric membrane electrodes. All of the [14]Tetraazaannulene nickel complexes, except 3, were found to exhibit high selectivity for the I -ion over the SCN -ion, although considerable interference of the ClO4 -ion was observed in all 1 -4 complexes.…”

“…27 Therefore, ISEs based on Co(II) and Ni(II) complexes of a cyclam with three n-octyl groups are attractive due to their I Nickel(II) complexes of [14]tetraazaannulene derivatives incorporating aromatic rings into their azaannulene framework were synthesized, and the anion-selectivity of the [14]tetraazaannulene nickel complexes 1 -4 was evaluated by potentiometric measurements with solvent polymeric membrane electrodes. All of the [14]Tetraazaannulene nickel complexes, except 3, were found to exhibit high selectivity for the I -ion over the SCN -ion, although considerable interference of the ClO4 -ion was observed in all 1 -4 complexes. Concerning the anion-selectivities of 1 and 4, the incorporation of naphthalene rings into the azaannulene framework decreased not only the interference of the ClO4 -ion but also the I -ion-selectivity over the SCN -ion.…”

“…1H-isochromen-1-one 14 and methylbenzimidazole 15 as substituents into the cyclam. Interestingly, the number of benzyl groups as introduced substituents on the nitrogen atoms of the cyclam determined the Cu 2+ , Ag + or non ion-selectivity.…”

“…Keywords [14]Tetraazaannulene, nickel complex, anion-selectivity, substituent effect, ion-selective electrode, DFT calculation, topological property, electrostatic property [14]Tetraazaannulene (1,8-dihydro- [1,4,8,11]tetraazacyclotetradeca-2,4,6,9,11,13-hexaene) is a 14-membered azaannulene containing four nitrogen atoms, which is an analog of the cyclam. [14]Tetraazaannulene derivatives have more rigid molecular structures than cyclam analogs due to the C=N and C=C bonds in the azaannulene framework.…”