Dear Diego,

prior to answer your vague formulated question, please define the " some dyes"  and give name or infos about them .

Please define bioassays .

Textiles dyes have trade name and most of them  are protected .

Please see my profil before you reinvent the weehl!

JRG

Check the old Colour Index, you will find a lot of information there.

Dear Diego,

Zarrin and Jordi posted valuable answers. I send you 5 ETAD jpg files  and you can see the sense of my sentence : " before you reinvent the wheel".

Please try to obtain publications of ETAD via Switzerland. There is a part concerning the aquatic toxicity.

I worked with the physical chemistry  and chemistry of dyes and textiles dyes since 1968 to 2009.

Please try to obtain the following 2 books (see 1,2,3jpg files). They contains a lot of infos concerning the structure.

Please don't collect our answers but answer a.s.a.p. if you want to receive a help of answerers.

If your research is confidential you can answer via  Message (only xou and me can read the text of your answer).

JRG

Diego hi,

can't help you by far at the level of JRG.

Anyhow, I can recall that we dealt with these problems in the sixties in Italy.

May be you can find something int the 'Biblioteca storica Montedison'.

Did not check what did happen to the library of Montefibre.

Have also a look at the site http://tessileesalute.it/.

All the best and

kind regards

Tony

Dear All,

 the colour index is not unambiguous and in our case some of the distributors do not know the exact chemical structure of the dyes they sell.

Moreover, It happened for example that different color index identify the same molecule or mixture (or at least the one we tested). An example? acid and acid orange 95 orange Article 33.One of the reviewers has rejected the work saying that the structures were not correct even though in many cases our representation shows a tautomer. We did a check on public sites such chemagora, ChemID, PubChem but without success in limited case

Hi Diego,

if the reviewer rejected the work because of the structures you considered we can suppose that he/she is an expert of dyes chemistry. But if the point is the representation of a different tautomer (eg. Azo-hydrazone) well this is not a real problem to me if you can support your choiche (generally the most probable is used). A different point is if you have to manage mixtures of different isomers or products with an unknown/ confidential composition.

What do you mean with "We did a check on public sites such chemagora, ChemID, PubChem but without success in limited case". Are you able to obtain a chemical composition or not? 

All the best!

Nicola we can not ask to the reviewer to check our structure also because we do not known his/her identity.

We need to find someone that can confirm or modify the structure we found.

Dear Diego,

I send you the following link :

http://www.worlddyevariety.com/acid-dyes/acid-orange-95.html

A confirmation can be found if you investigate this dyes with elemental analysis, NMR, MS Maldi TOF , UV-Vis and , important , reduce the 2 azo-bridges and check the amines (with NMR, MS, .....).

The Cy (see link) gave the synthesis pathway of Acid Orange 95

For aquatoxicity investigations, you must have the pure dye. Minor impurities can be very toxic too.

Can you investigate  the structure of dyes with the above cited methods (NMR ...)  in your department?

When you write :

We need to find someone that can confirm or modify the structure we found.

Do you mean a colleague on Research Gate or in your Uni e.g. department?

JRG

Dear Diego,

I send you jpg files of 2 books useful for your azo dyes investigations.

The chapter 3  (page 95 to 162) about azo dyes (Gordon and Gregory/ 1983/details see jpg file)  and the reference 8 in page 386  (Book Fierz-David and Blangey 1946 /Farbenchemie/Chapter V ) are worthwhile to be read

Good luck

JRG

Dear Diego, Dear Nicola,

It seems that you have the same interest concerning the azo dyes and toxicity.

When you  (Diego)write:

Moreover, It happened for example that different color index identify the same molecule or mixture (or at least the one we tested). An example? acid and acid orange 95 orange Article 33.One of the reviewers has rejected the work saying that the structures were not correct even though in many cases our representation shows a tautomer. We did a check on public sites such chemagora, ChemID, PubChem but without success in limited case

Are there some experts on dyes structures? - ResearchGate. Available from: https://www.researchgate.net/post/Are_there_some_experts_on_dyes_structures [accessed Oct 20, 2016].

I give you some comments about your sentences:

Please see always the CI   year of publication.

Concerning Acid Orange 95  :

Have you bought this azo dye? If yes, USA or China or in your country via a reseller?

Synthesis of the dye can be read in my answer (see above and my joined jpg file)

If you have submitted your publication to a peer reviewer:

-Please send me the reject'  s sentence via message(Only you and me can read our text). and a picture of your structures.

Have you checked the structure of Acid Orange 95  with NMR and MS Maldi Tof.

It is worthwhile to investigate the azo and hydrazone tautomers (see Nicola' s answer too) for a aquatoxicity study of it.

The cyclohexane bridge yields to a strong steric hindrance and distorsion. It can be seen with 3D modeling (ACD labs p.e.).

JRG

NMR and FTIR analysis can help in evaluating dye structures

If I understood well the problem can be fixed contacting the revisor to clarify what are specifically the supposed erros on the structures.

Probably he/she is simply checking on a different database which consider another tautomeric structure (eg Azo-hydrazone, enol-keto, lactam-lactim, amide-amidic acid, amine-imine and so on). This does not mean that your structures are wrong ;-)

If you think the SMILES are correct and you choosed a specific tautomer justify your choice and... That's all folks!

Greetings

Nicola

I agree with Nicola 's answer and I am waiting a " small or big feedback" of Diego.

JRG

Dear JRG i will comunicate to you the decision we will took