Chlorophyll d (Chl d) is a form of
chlorophyll, identified by
Harold Strain and
Winston Manning in 1943.[1] It was unambiguously identified in Acaryochloris marina in the 1990s.[2] It is present in
cyanobacteria which use energy captured from sunlight for photosynthesis.[3] Chl d absorbs
far-red light, at 710 nm wavelength, just outside the optical range.[4] An organism that contains Chl d is adapted to an environment such as moderately deep water, where it can use far red light for photosynthesis,[5] although there is not a lot of visible light.[6]
Chl d is produced from chlorophyllide d by
chlorophyll synthase. Chlorophyllide d is made from chlorophyllide a, but the oxygen-using enzyme that performs this conversion remains unknown as of 2022.[7]