Chemistry: What’s a Chromophore?

One online definition of chromophore is "an atom or group whose presence is responsible for the color of a compound." Although one may think of a chromophore that includes a metal atom such as copper, nickel, or cobalt, in organic chemistry a chromophore is more likely to consist of a collection of carbon-carbon multiple bonds, perhaps with modifying features. It is the organic variety we discuss in this article. Multiple Bonds Most organic compounds incorporate one or more of three carbon-to-carbon bond varieties: single bonds, double bonds, triple bonds. When drawing a basic organic compound, these are usually represented by: C–C, C=C, and C≡C, respectively. Although such notations are quite useful, they afford little information concerning bond nature and behavior. Bond Hybridization The best working hypothesis for bonding between atoms…
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Was Mom Right? Is Eating Carrots Good for the Eyes?

Chemistry, Food
From childhood, Mom admonished me, "Eat your carrots! They're good for your eyes." Now, I wore glasses. Later, with Mom's approval, I became an organic chemist. Since I listened to Mom, I eat my carrots. In fact, with lots of butter and salt, I rather enjoy them! But throughout my youth, I always wondered if they really are good for our vision. Here's what I learned. Carrot Chemistry Carrots contain the organic compound β-carotene. It's chemical structure is seen in the image below. The chemical formula of β-carotene is C40H56. In addition to imparting the orange color to a carrot, if a molecule is split down the middle and the cleaved double bond is hydrated for both halves, the result is two molecules of retinol, C20H30O. See the image. Carrots…
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