Design of bisquinolinyl malonamides as Zn2+ ion-selective fluoroionophores based on the substituent effect
摘要:
A series of malonamides possessing two quinoline moieties were synthesized and characterized as fluoroionophores for the Zn2+ ion. We focused on the relationship between the substituents introduced to the C2-position of the malonamides and their Zn2+ ion-selectivity, exploiting the structural effect of the substituents in the design of the fluoroionophores with high selectivity. The substituents introduced to the malonamides were the methyl, benzyl and naphthalenylmethyl groups. In dimethyl sulfoxide solvent, all substituted bisquinolinyl malonamides showed excellent fluorescence sensing for the Zn2+ ion, while unsubstituted bisquinolinyl malonamide 1 displayed ratiometric sensing for the Co2+ ion. N,N'-Bis(8-quinolyI)-2-methyl-2-naphthalenylmethyl malonamide 4 exhibited the highest Zn2+ ion-selectivity against the Cd2+ ion. Although the substituents introduced into the C2-position are spatially distant from the quinoline recognition moiety, this study indicated that they greatly influenced the ion selectivities of the bisquinolinyl malonamides. Furthermore, it was demonstrated that visible fluorescence analyses could be performed on malonamide 4. (C) 2014 Elsevier Ltd. All rights reserved.
Ni(II)-tetradentate amido-quinoline complexes effectively catalysed C–H chlorination of a series of hydrocarbons in the presence of NaOCl and acetic acid. The bond dissociation energy of the C(sp3)–H bond of the substrates varies from 99.3 kcal mol−1 (cyclohexane) to 87 kcal mol−1 (ethyl benzene). Exclusively chlorinated products (TON: 220 for cyclohexane) were obtained without any hydroxylated products