Retrieving "Organic Colorant" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Chromophore

   Linked via "organic colorants"

   $\pi \to \pi^*$ Transitions
   These are the most common transitions in organic colorants, found in compounds with extended systems of alternating single and double bonds (polyenes). Increasing the extent of conjugation (the length of the effective $\pi$ system) invariably lowers the $\text{HOMO-LUMO}$ gap, leading to a bathochromic shift (a shift to longer, lower-energy wavelengths). For instance, the shift from carotene (yellow/orange) to [lycopene](/entries/ly…