Chlorophyll: At the green source of life

Chlorophyll exists since ca. 3 billion years and is at begin of the evolution. This chiral, green Mg-porphyrin-complex absorbs as a photosensitizer in the antennas of the light-harvesting complexes of chloroplasts all parts of visible light except of green light. This energy is transferred to the reaction centres of oxygenic photosynthesis. By this redox reaction carbon dioxide and water are transformed into carbohydrates and oxygen. We describe how the structures of chlorophylls were elucidated, discuss structure-property relations, the relationship to heme of blood, everyday uses, and how Green has influenced our language. The isolation of pure chlorophyll a from spinach is an experimental challenge, which we report in detail. All analytical spectra were recorded and are reproduced and interpreted either in the main part or in the supporting information.