[tony.hegyes]

Good day!

I have stumbled upon the following question: What happens when you add Br2 dissolved in CCl4 to lycopene? The good answer was that it loses its colour.

Could someone explain to me please why so? And is this a general rule for all dyes?

Thank you!

[sjb]

Good day!

I have stumbled upon the following question: What happens when you add Br2 dissolved in CCl4 to lycopene? The good answer was that it loses its colour.

Could someone explain to me please why so? And is this a general rule for all dyes?

Thank you!

What functionality does lycopene have? Does this react in any way with bromine?

[tony.hegyes]

Yes, the two do react. Bromine atoms break a few pi-Bonds.

[fledarmus]

A molecule wouldn't appear colored unless it was absorbing radiation in a visible wavelength. What structure in lycopene can absorb visible light? How might this structure change if you add bromine?

This might help: http://homepages.gac.edu/~anienow/CHE-372/Labs/Conjugated%20Dyes.pdf

[tony.hegyes]

Thank you Fledarmus! It seems that lycopene loses its colour because of the missing pi-Bonds - the effect of bromium addition.

[AWK]

Bromine also loses its color!