October 03, 2022, 05:16:53 AM
Forum Rules: Read This Before Posting


Topic: Lycopene reaction with Br2 - water  (Read 6502 times)

0 Members and 1 Guest are viewing this topic.

Offline tony.hegyes

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Lycopene reaction with Br2 - water
« on: March 14, 2012, 06:41:53 AM »
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!

Offline sjb

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 3643
  • Mole Snacks: +221/-42
  • Gender: Male
Re: Lycopene reaction with Br2 - water
« Reply #1 on: March 14, 2012, 07:05:28 AM »
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?

Offline tony.hegyes

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Re: Lycopene reaction with Br2 - water
« Reply #2 on: March 14, 2012, 07:19:39 AM »
Yes, the two do react. Bromine atoms break a few pi-Bonds.

Offline fledarmus

  • Chemist
  • Sr. Member
  • *
  • Posts: 1676
  • Mole Snacks: +203/-28
Re: Lycopene reaction with Br2 - water
« Reply #3 on: March 14, 2012, 07:25:16 AM »
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

Offline tony.hegyes

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Re: Lycopene reaction with Br2 - water
« Reply #4 on: March 14, 2012, 07:30:08 AM »
Thank you Fledarmus! It seems that lycopene loses its colour because of the missing pi-Bonds - the effect of bromium addition.

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7982
  • Mole Snacks: +555/-93
  • Gender: Male
Re: Lycopene reaction with Br2 - water
« Reply #5 on: March 14, 2012, 09:18:18 AM »
Bromine also loses its color!
AWK

Sponsored Links