Ob. Sutcliffe et al., Voltammetric metal cation sensors based on ferrocene derivatives with oxazoline and imine substituents, J ORGMET CH, 637, 2001, pp. 134-138
Ferrocene derivatives la, lb and 2 containing oxazoline substituents act as
efficient voltammetric sensors of Mg2+ and Ca2+ ions in acetonitrile solut
ion in concentrations as low as 10 mol%: a new redox peak appears in the cy
clic voltammogram, positively shifted by 310-360 mV for 1a and 1b, and by 1
60-190 mV for 2, compared to E-1/2 of the free ligand. For the bisferroceny
ldiimine derivative 3 the shift is 150-160 mV. Compounds la, lb and 3 are a
lso responsive to Cu2+ ions (shifts of 250, 320 and 160 mV, respectively) a
nd compound 3 is responsive to Zn2+ ions (150 mV shift) with no interferenc
e from a large excess of several other metal salts. UV-vis spectrophotometr
ic studies and H-1-NMR titration experiments confirm that the oxazoline or
imine groups are the sites of metal complexation. (C) 2001 Elsevier Science
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