The kinetics of redox reaction between N,N′-phenylenebis-(salicylideneiminato)iron(III), hereafter referred to as [FeSalphen]+, and hypophosphorous acid was studied in mixed aqueous medium (DMSO:H2O; 1:4 v/v) under pseudo-first-order conditions at 26 ± 1 °C, µ = 0.2 C2 mol dm−3 (NaCl) and λmax = 435 nm. The reaction was found to be first-order in both reactants second-order overall, acid independent and displayed zero Brønsted–Debye salt effect. Evidence for the presence of free radicals was obtained during the course of the reaction, but none to support the formation of an intermediate complex. In general, the data obtained suggest an outer-sphere mechanism for the reaction. A plausible mechanism is proposed.

中文翻译：

---

N,N'-亚苯基双-(水杨亚基)铁(III)与次磷酸在混合水介质中的氧化还原反应

在混合水性介质 (DMSO:H2O; 1:4 v/v) 中研究了 N,N'-亚苯基双-(水杨亚基亚氨基)铁 (III)（以下称为 [FeSalphen]+）和次磷酸之间的氧化还原反应动力学) 在 26 ± 1 °C 的伪一级条件下，μ = 0.2 C2 mol dm-3 (NaCl) 和 λmax = 435 nm。发现该反应在两种反应物中都是一级反应，总体上是二级反应，不依赖于酸，并且显示出零 Brønsted-Debye 盐效应。在反应过程中获得了自由基存在的证据，但没有证据支持中间复合物的形成。一般来说，获得的数据表明反应的外球机制。提出了一种合理的机制。