You should tell clearly or decide for what purpose you are using 3,4,5-trihydroxyphenyl group. Also if you have a nitrogen donor group on this molecule, it is unlikely that the same metal bound to N-atom would bind to one of the OH groups (or as phenoxide ) even if you use a base, as it is away from the metal center. On the other hand, it can bind to another metal atom, in case if you have not followed proper stoichiometry. To judge the coordination behavior, please make models of your ligand system and try to connect the donor sites to the metal center and you will understand it very easily.

Best wishes

Balakrishna

Mr. Balakit,

The coordination capability of OH-phenyl group is low, in general; furthermore, it depends strongly on the pH of the medium.

Moreover, with increasing in the spectrum of pH values, such ligands participate frequently into heavy metal ions catalyzing reactions leading to their adducts. For instance, please, consider work [1].

[1] Chemical Engineering Journal, 226 (2013) 113-122

Organometallic Sn(II) catalyzing adducts of substituted benzaldehydes

Bojidarka Ivanova, Michael Spiteller

Thank you so much Bojidarka B. Ivanova and Balakrishna Maravanji

Dear Asim A. Balakit to me the question remains why you want to have the 3,4,5-trihydroxyphenyl group present in your bidentate imine ligand? As mentioned by Bojidarka B. Ivanova free –OH groups do not easily coordinate to e.g. transition metals. However, as soon as you work in a basic reaction medium, the –OH groups can be deprotonated to form strong anionic phenoxide ligands. In your case this could then lead to complications such as the formation of product mixtures and / or insoluble polymeric materials.

Thanks a lot Frank T. Edelmann

The point of having 3,4,5-trihydroxyphenyl is to increse the antioxidant activity of the desigend ligand and do a comprative study with similar ligands.

Dear Asim A. Balakit thanks for the explanation. Increasing the antioxidant activity of the ligand by using the 3,4,5-trihydroxyphenyl ligand certainly makes sense. Just keep in mind that the many –OH groups could lead to complications and formation of polymers. We observed the latter frequently when studying metal complexes of curcumin. For more information on this please see the review article cited below.

Article ChemInform Abstract: Metal Complexes of Curcumin — Synthetic...

The article is freely available as public full text on RG.

Dear Asim A. Balakit please also see this potentially useful article in which the authors employ the 3,4,5-trihydroxyphenyl substituent in their ligand. The work is entitled

N-acylhydrazone inhibitors of influenza virus PA endonuclease with versatile metal binding modes

https://www.nature.com/articles/srep31500?proof=t

The paper is Open Access and freely available as full text from the general internet.