SEARCH Articles Figures Tables FUNCTIONAL COMPOUNDS CONTAINING OXYGEN, SULPHUR OR NITROGEN AND THEIR DERIVATIVES Four-membered Rings containing Oxygen and One Sulphur Atom Four-membered Rings containing Sulphur and Oxygen Heterocycles Containing Nitrogen, Oxygen, and Sulphur Other Oxygen- and Sulphur-containing Systems Oxygen and Sulphur Derivatives Oxygen and sulphur donor ligands Oxygen sulphur Oxygen, Sulphur, Selenium, and Tellurium Oxygen, Sulphur, and Selenium Oxygen- and Sulphur-containing Heterocycles Oxygen-, Sulphur-, and Selenium-bonded Compounds REACTIONS WITH ELECTROPHILIC OXYGEN AND SULPHUR