Chromophore

A chromophore is the part of a <a href="/facts/Molecule/N9ljSfFq">molecule</a> responsible for its <a href="/facts/Color/a1QSEJhj">color</a>. The word is derived from <a href="/facts/Ancient_Greek_language/LIK7NlUh">Ancient Greek</a> χρῶμᾰ (chroma) 'color' and -φόρος (phoros) 'carrier of'.
The color that is seen by our eyes is that of the light not <a href="/facts/Absorption_(electromagnetic_radiation)/xBYKt7yS">absorbed</a> by the reflecting object within a certain <a href="/facts/Wavelength/kcJU0ymz">wavelength</a> spectrum of <a href="/facts/Visible_spectrum/frPBh8o5">visible light</a>. The chromophore is a region in the molecule where the energy difference between two separate <a href="/facts/Molecular_orbital/0dP30jaa">molecular orbitals</a> falls within the range of the visible spectrum (or in informal contexts, the spectrum under scrutiny). Visible light that hits the chromophore can thus be absorbed by exciting an <a href="/facts/Electron/L0KBo5cW">electron</a> from its <a href="/facts/Ground_state/ML7cfCug">ground state</a> into an <a href="/facts/Excited_state/czcLYNnr">excited state</a>. In biological molecules that serve to capture or detect light energy, the chromophore is the <a href="/facts/Moiety_(chemistry)/WxKqcJe1">moiety</a> that causes a <a href="/facts/Conformational_change/q23CgKgo">conformational change</a> in the molecule when hit by light.

Chromophore open-in-new

Chromophore