This paper presents the synthesis and characterization of a series of novel monomeric aqua‐ligated iron(III) complexes, [FeIII(L5R)(OH2)]2+ (R = OMe, H, Cl, NO2), supported by an amide‐containing pentadentate N5 donor ligand, L5R [HL5R = 2‐(((1‐methyl‐1H‐imidazol‐2‐yl)methyl)(pyridin‐2‐yl‐methyl)amino)‐N‐(5‐R‐quinolin‐8‐yl)acetamide]. The complexes were characterized by various spectroscopic and analytical techniques, including electrochemistry and magnetic measurements. The Fe(III)‐hydroxo complexes, [FeIII(L5R)(OH)]1+, were generated in situ by deprotonating the corresponding aqua complexes in a pH ~7 aqueous medium. In another way, adding one equivalent of a base to a methanolic solution of the Fe(III)‐aqua complexes also produced the Fe(III)‐hydroxo complexes. The study uses linoleic fatty acid as a substrate to explore the hydrogen atom abstraction (HAA) reactivity of both hydroxo‐ and aqua‐complexes. The investigation highlights the substitution effect of the L5R ligand on reactivity, revealing a higher rate when an electron‐withdrawing group is present. Hammett analyses and(or) determination of the asynchronicity factor (η) suggest an oxidative asynchronous concerted proton‐electron transfer (CPET) pathway for the HAA reactions. Aqua complexes exhibited a higher asynchronicity in CPET, resulting in higher reaction rates than their hydroxo analogues. Overall, the work provides insights into the beneficial role of a higher imbalance in electron‐transfer‐proton‐transfer (ET‐PT) contributions in HAA reactivity.