[ygul]

I have prepared 20% TICl4 in 80 % HCl under flowhood on ice but I can not detect any reactivity of TiCl4 with H2O2. Why is that? I should be able to have an absorbance of reaction at 450 nm (0.2 to 0. in the presence of H2O2 (20-100 ug/ml) and 10-25 % TCA (trichlroacetic acid). I am seeing a yellow color formation and a major peak at 325 nm. That is it.

20%TiCl4 in 80% HCl is not kept under inert gas, kept in regular air thight brown bottle for couple of months at room temperature.

1.5 mL polypropylene microcentrifuge tubes have been used for reaction.

[discodermolide]

Pray tell us what you were expecting to see?

[ygul]

Pray tell us what you were expecting to see?

I am expecting absorbance of the reaction product at 450 nm

[discodermolide]

Sorry, I meant chemically.

[ygul]

Sorry, I meant chemically.

Ti-peroxide? I am not chemist no idea.

[Arkcon]

Do you have a reference that says what molecule is created, that has a chromaphore in the visible, from TiCl₂ and H₂O₂?  Should you even be mixing a powerful reducing agent (Wikipedia says TiCl2 will relese hydrogen from water) with a strong oxidizing agent?  How will you get the color from the TCA?  What is TCA dissolved in?  Because it is decomposed by water, and you do have some with your H₂O₂, correct?

[orgopete]

I'd check the hydrogen peroxide, you used very little and its titer may be low. You also didn't indicate the concentration. The more concentrated solutions decompose more rapidly.

[ygul]

I'd check the hydrogen peroxide, you used very little and its titer may be low. You also didn't indicate the concentration. The more concentrated solutions decompose more rapidly.

you were right, H2O2  stock was at 3 % but I needed to use 10 times more to to  detect TI-peroxy complex which is detectible at 425 nm. thanks for advice

[ygul]

Do you have a reference that says what molecule is created, that has a chromaphore in the visible, from TiCl₂ and H₂O₂?  Should you even be mixing a powerful reducing agent (Wikipedia says TiCl2 will relese hydrogen from water) with a strong oxidizing agent?  How will you get the color from the TCA?  What is TCA dissolved in?  Because it is decomposed by water, and you do have some with your H₂O₂, correct?

TiCL4 is in 80 % HCl but problem was that  H2O2 is  at  lower concentration than I knew (labelled on bottle). This was my reference for Ti-devicine (aglycone of vicine) complex   

[Arkcon]

OK, I don't have access (right now) to the references that I've found to the Ti-peroxy complex that can be made, but if your suggests a greater than 3% (aka household) strength peroxide, then you should use that, or you're likely diluting your complex too much.

http://en.wikipedia.org/wiki/Transition_metal_dioxygen_complex