[khemauck]

Hi,

I know that chlorophyll is more polar than carotene because of the amount of polar bonds in chlorophyll.

My question is, which bonds in chlorophyll are the most polar? I want to say that the Mg - N bonds are because of the greater difference in electronegativity than the difference in the carbonyl bonds.

Would I be correct in making this assumption?
Cheers!

[Arkcon]

Here's a page with many phytopigments and their structures.  Compare them and look for other groups that would contribute. http://christopherking.name/Organic%20I%20Labs/Plant%20pigments%20by%20TLC.htm

[Babcock_Hall]

Polarity is a complex phenomenon that is associated with more than just the dipole moments of individual bonds.  I would look at the intermolecular forces that each molecule experiences.