Questions tagged [dye]

For questions related to compounds for producing color (intentional or not).

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Conversion of Erythrosine to Fluorescein

I am a home-chemist and I love dyes. I recently got my hands on sodium salt of erythrosine (tetra-iodinated fluorescein). I want to convert erythrosine to fluorescein. I speculate that using dilute ...
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42 views

Rate constants and their relationship to quantum yields

Question A dye molecule has a singlet excited state lifetime of $\pu{0.85 ns}.$ The quantum yield of triplet formation is $35~\%.$ What is the rate constant for intersystem crossing from the ...
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1answer
101 views

Indigo and the Environment: is it that bad?

TL;DR: In what aspects are the products of the indigo vat dyeing process (sodium sulphate, sulphite and thiosulphate ions) harmful to the environment or to living beings? I was recently looking into ...
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Mixing ink with alcohol, MEG and water

First of all, I'm not a chemist and my knowledge in chemistry is not that extensive. However, I would like ask the following question: are there any chemical reasons that would explain that mixing a ...
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1answer
253 views

Which compounds react positively in the aniline dye test?

I read that to test for the presence of phenol groups in an organic compound the aniline dye test can be performed. If the solution has phenol present it gives a red or orange precipitate to confirm ...
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1answer
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Looking for a dye which emits around 680 nm

For a specific experiment, I'm looking for a dye which would emit around 680 nm. Preferably one I could buy easily commercially. Are there any databases which might give the emission spectra of ...
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37 views

Is there dye that attaches only to human DNA? [closed]

I am looking for simple way to tell if blood stain is from human blood or some other animals. I know there are fluorescent DNA dyes, but is there dye that only attaches to human DNA?
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1answer
62 views

Does there exist a dye that will primarily bind with water in a water/oil emulsion?

I'm wondering if there exists a type of dye that will bind primarily with water when introduced to a water/oil emulsion. That way if the water is centrifuged to the bottom of the vial, it will be dyed ...
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41 views

Reduction of triphenylmethane dyes in ink

Right now I'm trying to explain why the ink from an ink pen turns colourless in water. I know that the pH is responsible as it breaks apart the conjugated system of double bonds. I'm just not sure on ...
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50 views

How can I preserve chlorophyll for long periods of time?

I'm currently working on a XIX century photographic process called Anthotype. It relies on organic colored substances that fade when exposed to sunlight. For the substances I've tried alcoholic ...
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1answer
38 views

How to make equal density pool dye without diffusion

I have a leak I have been struggling to find in my in-ground pool. I am losing about 1/4" of water per day and I believe the issue is one of the fittings in the bottom of the pool. There are two ...
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1answer
670 views

Why does SYBR green emit more signal when bound to DNA?

Principle of SYBR Green SYBR Green I (SG) is an asymmetrical cyanine dye used as a nucleic acid stain in molecular biology. (wiki) This molecule is commonly used in qPCR to meassure the ...
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2answers
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Mechanism of formation of 2-naphthol red dye (aka Sudan 1)

As you can see in the image diazonium can attack at 2 different positions to form different products then why only the first product is correct? As there are two ortho positions available why does it ...
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1answer
90 views

Strange green and gold coloured chemical [closed]

I have a reagent bottle with an unknown chemical that came with some other lab gear about 30 years ago, I stumbled on it again when clearing out some old stuff. It is a standard brown glass Merck of ...
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2answers
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Do indigo and leuco-indigo have fully conjugated pi systems?

I've just come across a figure indicating the positions of conjugated bonds in indigo and leucoindigo, and I'm quite confused about why both molecules aren't fully conjugated. My reasoning is as ...
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133 views

Anthracine blue composition

In 1873 a German chemist named Springmühl announced a derivative of alizarin which acted as a blue dye and he sold this dye for a high price. The dye was sometimes called "anthracine blue" and ...