What are the appropriate conditions for making the reaction take place between FeCl3 & suitable plant to reduce Fe+3 to Fe+2 (Apart from forming iron oxide), without forming IronPolyphenols?
where the difficulty is due to chelation process that occurs by polyphenols found in the plant.
so how can i overcome the problem?
Mahdavi, Mahnaz, et al. "Green biosynthesis and characterization of magnetic iron oxide (Fe3O4) nanoparticles using seaweed (Sargassum muticum) aqueous extract." Molecules 18.5 (2013): 5954-5964.
Omar Yousef
We have studied in detail the mechanism of reduction of silver and gold ions with a pure reducing agent, rutin. It is present in all extracts. All phenolic compounds in plant extracts contain phenolic groups that are oxidized to quinone groups. It is quite possible that chelates with iron ions appear at the first stage. This process proceeds quickly and we did not notice the formation of chelates. The process of nanoparticle formation proceeds according to the following scheme. Reduction of ions (fast), formation of nuclei of nanoparticles (fast), growth of nanoparticles (slow). The article given by Azeez Abdullah Barzinjy also hints at such a mechanism. A similar mechanism should be in the reduction of Fe3+ in Fe 2+ of magnetite.
Article Kinetics and mechanism of the interaction between HAuCl4 and rutin
Article Investigation of interaction between silver ions and rutin i...
Article Preparation and bactericidal properties of silver nanopartic...
Yuri Mirgorod & Azeez Abdullah Barzinjy
many thanks
But I tried many plants as a reducing agent, one of them Eucalyptus, I noticed when I start to add 0.05 M FeCl3 dropwise to Eucalyptus extract, iron polyphenols will be formed immediately, where color of mixture "during dropwising" will start to change from reddish black to dark navy, which indicates to changing of the chelation coordination bonds pattern between iron radicals & polyphenols, which means iron polyphenols was formed..Isn't that right?
Furthermore, according to standard reduction potentials for iron completely different from Au & Ag, so it's so easy to reduce Ag and Au by most kinds of plants.
So, how can to overcome the formation of iron polyphenols?
Ibrahim Alghoraibi
Omar Yousef
Plant extracts can contain many phenolic-type reducing agents. Maybe gallic acid and others. Therefore, iron salts can form. Try lowering the temperature to form a precipitate that can be removed by filtration. Then the already filtered extract can be used again for reduction. Also, why do you care about color change. If you received magnetite nanoparticles, then they are brown. Otherwise, small magnetite nanoparticles and iron polyphenols can be together in a dispersed system.
Dear Omar Yousef thank you for sharing this very interesting technical question with the RG community. Unfortunately you did not really specify the goal of your experiments. Is the final goal just the reduction of Fe3+ to Fe2+ or the formation of some sort of iron-containing nanoparticles?
As for the prevention of the formation of iron-polyphenol complexes, please have a look at the following potentially useful PhD thesis in which this problem has been studied in detail:
Prevention of Iron-Polyphenol Complex Formation in Iron Fortified Tea
https://www.semanticscholar.org/paper/Prevention-of-Iron-Polyphenol-Complex-Formation-in-McGee/9e27c27f05c0b74a590281860654992b90720beb
(please see attached pdf file)
Also please check this relevant article:
Prevention of iron-polyphenol complex formation by chelation in black tea
Article Prevention of iron-polyphenol complex formation by chelation...
This paper is freely available as public full text on RG so that you can download it as pdf file.
Good luck with your work and please stay safe and healthy! With best wishes, Frank Edelmann
Dear Dr Omar Yousef . See the following useful RG link: Article Fe3+–Fe2+ Transformation Method: An Important Antioxidant Assay
Kindly see also the following very good RG link: Article Differential effects of Fe2+ and Fe3+ on osteoblasts and the...
Also check please the following useful RG link: Article Green synthesis of iron oxide nanoparticle using Carica papa...
Dr Frank T. Edelmann
Dr Aref Wazwaz & Dr Yuri Mirgorod & Dr Azeez Abdullah Barzinjy
Many thanks all of you for that useful answers.
Dr Frank T. Edelmann I appreciate your help.
I'm trying to form Iron Oxide (IONPs) by using Eucalyptus extract (Eu) and FeCl3, that's my final goal, but I'm suffering from formation of iron-polyphenol complex where i tried many ways to get on Iron Oxide but that didn't work, unless the iron-poltphenol complex "that's outcome of reaction between Eu & FeCl3" was treated thermally at 300 C or more.
"For the record, I had used black tea & olives leave instead of Eucalyptus and I got same result(iron-polyphenol)"
I read many articles talking about green synthesis of IONPs by plants leaves, black tea extract or something else like that, where they hadn't even mentioned to formation of iron-polyphemol complex. How could they do it without thermal treatment or "without adding two precursor Fe+3 +Fe+2 and rise PH" ??! (only add leaves extract to one precursor Fe+3 and the result is iron oxide)?!
Dear Omar Yousef
This article might be helpful for your problem with reducing ferric to ferrous:
Article Recovery of iron from direct reduction iron sludge and biosy...
Dear Omar Yousef many thanks for your kind response and explanation. I'm really not a specialist in this field anough to give you an absolutely qualified answer. However, you might have to consider the possibility that Eucalyptus extract (Eu) contains too many strongly coordintaing (chelating) polyphenol ligands that a calcination step is necessary in the end. By the way, how do you know that you obtained iron-polyphenol complexes instead of iron oxide nanoparticles?
I just came across a potentially useful article in which the preparation of iron nanoparticles (INPs) by using Eucalyptus extract (Eu) and (NH4)2Fe(SO4)x6H2O has been reported. Please have a look at this paper:
Synthesis of Iron Nanoparticles from aqueous extract of Eucalyptus Robusta Sm and evaluation of antioxidant and antimicrobial activity
Article Synthesis of Iron Nanoparticles from aqueous extract of Euca...
This paper is freely available as public full text on RG. However, I'm not sure how well characterized the INPs are which the authors obtained in this study.
Perhaps you need to play around with the pH of your reaction mixtures or try another iron precursor.
I hope this halps. Good look with your research and best wishes, Frank Edelmann
You can use the solution of 10% hydroxylamine hydrochloride for reducing Fe3+ to Fe2+ followed by mixing for 15 min
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