Addition of Pb(NO3)2, CrCl3 and CdCO3 to the solutions
of the flavylium chloride resulted in a spectra shift as
shown in Table 2. The spectra shift is as a result of the
formation of coordination complex between the flavylium
chloride and the individual metals. A Cyanidin-Pb (II)
complex was formed at pH 4.2 (max = 555 nm, in
methanol); A Cyanidin-Cr (III) complex was formed at pH
1.0 (max = 682 nm, methanol and ethanol) while a
Cyanidin-Cd (II) complex was formed at pH 3.0 [max =
706 nm (methanol) and 679 nm (ethanol)]. Aluminum and
tin have earlier been reported to cause a similar spectral
shift in the uv-visible spectrum of flavyluim chloride.
These shifts were attributed to the formation of coordination
complex, between the metals and the 3
1
-, 4
1
-othodihydroxyl
systems in the anthocyanidin (Harborne,
1958a, Zang et al., 2005). Phenolic compounds generally
have been shown to chelate with metal ions at the 3
1
-, 4
1
-