The synthesis and fluorescent properties of analogues of the zinc(II) specific fluorophore zinquin ester.
The synthesis and fluorescent properties in the absence and presence of zinc(II) of a range of 2-substituted derivatives of N-(6-methoxy-2-methyl-8-quinolyl)-4-methylbenzenesulfonamide are described. These analogues formed complexes with zinc(II) as indicated by a bathochromic shift in their UV/vis spectra. Analogues with isobutenyl and isobutyl side chains at the 2-position formed fluorescent complexes whose fluorescence was stronger than that of the 2-methyl-containing parent. These derivatives were converted, via conversion to the phenol with boron tribromide and reaction with ethyl bromoacetate, to systems with ester-containing side chains analogous to zinquin ester, a specific cellular fluorophore for zinc(II). All of these ester derivatives formed complexes with zinc(II) resulting in a bathochomic shift in their UV/vis spectra. Compounds with isobutyl, isobutenyl, and styryl side chains exhibited increased fluorescence compared to that of zinquin ester in the presence of zinc(II). The compound with the 2-isobutyl side chain was more selective in its fluorescence for zinc(II) over cadmium(II) compared to zinquin ester.
Kimber
M C
MC
Department of Chemistry, University of Adelaide, Adelaide, South Australia 5005, Australia.
Mahadevan
I B
IB
Lincoln
S F
SF
Ward
A D
AD
Tiekink
E R
ER
D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D008024:Ligands; D015363:Quinolones / Q000138:chemical synthesis* / Q000737:chemistry; D014105:Tosyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D005456:Fluorescent Dyes; D008024:Ligands; D015363:Quinolones; D014105:Tosyl Compounds; C084731:zinquin