PS_2.2 Highlights in Photosynthesis Research:

1771	: Joseph Priestley, England	: Discovers that plants can "purify" air that has been "burned out" by a candle.
1779	: Jan Ingenhousz, The  Netherlands	: Demonstrates that the plant in Priestley's experiment is dependent on light and its green parts.
1782 - 1804		: Several researchers show that carbon dioxide and water are stored as organic matter by plants.
1845	: Robert Mayer, Germany	: Points out that plants store solar energy in organic matter.
Ca 1915	: Richard Willstätter, Germany	: Suggests that chlorophyll plays an active role in plants (Nobel Prize in 1915).
Ca 1930	: Cornelis van Niel, USA	: Proposes that photosynthesis is based on oxidation-reduction reactions and that the primary reaction is a photolysis of water followed by oxygen evolution.
1932	: Robert Emerson and William Arnold, USA	: Conclude that several hundred chlorophyll molecules cooperate in photosynthesis.
1939	: Robert Hill, England	: Demonstrates that photolysis of water and carbon dioxide fixation are separate processes.
1940	: Hans Fischer, Germany	: Solves the chemical structure of chlorophyll. (Nobel Prize 1930 for his investigations of hemes and chlorophyll.)
1954	: Melvin Calvin, USA	: (Nobel Prize 1961) and coworkers unravel the reactions of carbon dioxide fixation (Nobel Prize in 1961).
1954	: Daniel Arnon, USA	: Discovers light-dependent synthesis of ATP (photophosphorylation).
1960 - 1961	: Robert Hill and Fay Bendall, England, and independently Louis  Duysens, The Netherlands	: Show how two separate photosystems cooperate in plants.
1968	: William Parson, USA	: Confirms Duysens' hypothesis (1956) that chlorophyll is oxidized in the primary reaction of photosynthesis.
1984	: Johann Deisenhofer, Robert Huber and Hartmut Michel	: The Federal Republic of Germany, solve the structure of a photosynthetic reaction center from a bacterium (Nobel Prize in 1988).
1992	: Rudolph A. Marcus	: For the  contributions to the theory of electron transfer reactions in chemical systems (Nobel Prize in 1992).

Source: Nobel Academy