Abstract This study reports an experimental exploration of the combustion inhibition efficiency of iron short-chain perfluorocarboxylates, namely, iron trifluoroacetate (FeTFA) and iron pentafluoropropionate (FePFP). The aim is to develop a new phosphor-free fire-extinguishing agent. The synthesized FeTFA and FePFP were characterized by ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray fluorescence measurements, and fast-atom bombardment mass spectrometry. The FeTFA and FePFP ligands (i) coordinate with the iron ions in bridging form via carboxylate oxygens, (ii) contain no Cl−, and (iii) are hexanuclear complexes with chemical formulas of C18F27O22Fe6 and C27F45O22Fe6, respectively. Suppression trials and thermogravimetric measurements revealed that (i) both FeTFA and FePFP have higher combustion inhibition ability at lower suppressant concentrations than ammonium dihydrogen phosphate (an active component in conventional fire-extinguishing agents), (ii) FePFP is remarkably more inhibition-efficient than FeTFA, and (iii) neither FeTFA nor FePFP hinder cellulose pyrolysis and char combustion in the condensed phase. Thermogravimetry–mass spectrometry measurements confirmed that (i) the main gas-phase decomposition product of FeTFA and FePFP is CF3, and (ii) FePFP is a better CF3 generator than FeTFA. The different inhibition abilities of the two complexes were attributed to their different CF3 generation abilities and eases of decomposing the complex.

中文翻译：

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短链全氟羧酸铁的合成及阻燃效率

摘要 本研究报告了对短链全氟羧酸铁，即三氟乙酸铁 (FeTFA) 和五氟丙酸铁 (FePFP) 的燃烧抑制效率的实验探索。目的是开发一种新的无磷灭火剂。合成的 FeTFA 和 FePFP 通过紫外-可见光谱、傅里叶变换红外光谱、X 射线荧光测量和快原子轰击质谱进行表征。FeTFA 和 FePFP 配体 (i) 通过羧酸根氧以桥接形式与铁离子配位，(ii) 不含 Cl−，(iii) 是六核配合物，化学式分别为 C18F27O22Fe6 和 C27F45O22Fe6。抑制试验和热重测量表明 (i) FeTFA 和 FePFP 在较低抑制剂浓度下比磷酸二氢铵（传统灭火剂中的一种活性成分）具有更高的燃烧抑制能力，(ii) FePFP 的抑制效率明显高于FeTFA 和 (iii) FeTFA 和 FePFP 都不会阻碍凝聚相中的纤维素热解和炭燃烧。热重-质谱测量证实 (i) FeTFA 和 FePFP 的主要气相分解产物是 CF3，(ii) FePFP 是比 FeTFA 更好的 CF3 发生器。两种复合物的不同抑制能力归因于它们不同的CF3生成能力和分解复合物的难易程度。