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Control of Fe³⁺ coordination by excess Cl^- in alcohol solutions.

ABSTRACT: We spectroscopically investigated coordination state of Fe³⁺ in methanol (MeOH) and ethanol (EtOH) solutions against Cl^- concentration ([Cl^-]). In both the system, we observed characteristic absorption bands due to the FeCl₄ complex at high-[Cl^-] region. In the MeOH system, the proportion (r) of [FeCl₄]^- exhibits a stationary value of 0.2-0.3 in the intermediate region of 10 mM < [Cl^-] < 50 mM, which is interpretted in terms of [FeCl _n L_6-n ]^3-n (n = 1 and 2). In the EtOH system, r steeply increases from 0.1 at [Cl^-] = 1.5 mM to 0.7 at [Cl^-] = 3.5 mM, indicating direct transformation from [FeL₆]³⁺ to [FeCl₄]^-. We further found that the coordination change significantly decreases the redox potential of Fe²⁺/Fe³⁺.

SUBMITTER: Nomura Y

PROVIDER: S-EPMC9204708 | biostudies-literature |

REPOSITORIES: biostudies-literature

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