Compound

Compound
Name	Compound
Caption	General representation of a chemical compound
Formula	variable
Molar mass	variable
Appearance	variable
Density	variable
Melting point	variable
Boiling point	variable
Solubility	variable
Identifiers	variable

Compound

A compound is a substance formed when two or more distinct chemical elements bond together in fixed proportions, producing a material with properties different from its constituent elements. Compounds are central to fields such as Mendeleev's periodic system, Daltonian atomic theory, Lavoisier's chemistry, Curie's radiochemistry, and Pauling's quantum chemistry, and underpin technologies developed by organizations like DuPont, Bayer, Pfizer, General Electric and institutions such as Massachusetts Institute of Technology, University of Cambridge, California Institute of Technology, Max Planck Society, and Imperial College London.

Definition and Classification

In chemical classification, a compound is distinguished from an element and a mixture, a distinction elaborated in texts by Jöns Jakob Berzelius, Justus von Liebig, Amedeo Avogadro, G. N. Lewis, and codified in nomenclature by IUPAC. Compounds are categorized by bonding type—ionic, covalent, metallic, coordinate—concepts refined by Gilbert N. Lewis, Linus Pauling, Walther Nernst, and Erwin Schrödinger. Classification schemes also include organic versus inorganic divisions, developed through work at institutions such as Royal Society of Chemistry and American Chemical Society, and subcategories like coordination complexes, organometallics, polymers, and network solids, topics covered in curricula at Harvard University, Stanford University, and University of Oxford.

Chemical Structure and Properties

Chemical structure and properties of compounds derive from atomic arrangement and bonding, described using theories from Quantum mechanics, valence bond theory, molecular orbital theory, and spectroscopic methods advanced by laboratories at CERN and National Institutes of Health. Structural characterization uses techniques developed at Bell Labs, Rutherford Appleton Laboratory, and European Synchrotron Radiation Facility, including X-ray crystallography pioneered by William Henry Bragg and William Lawrence Bragg, nuclear magnetic resonance spectroscopy advanced by Richard R. Ernst, and mass spectrometry improved by John Fenn and Kurt Wüthrich. Physical properties—melting point, boiling point, density, refractive index—are tabulated in handbooks by CRC Press, NIST, Merck Index, and databases maintained by PubChem and ChemSpider.

Synthesis and Preparation

Synthesis of compounds encompasses classical methods from Friedrich Wöhler's organic syntheses to modern strategies in total synthesis championed by E. J. Corey's retrosynthetic analysis and catalytic methods developed by Robert H. Grubbs, Richard F. Heck, Akira Suzuki, and Yoshinori Ohsumi-related biochemical techniques. Preparation techniques include stoichiometric reactions, catalytic hydrogenation used in work at Nobel-winning labs, electrochemical methods from Faraday's studies, photochemical methods influenced by Einstein's photoelectric insights, and green chemistry approaches promoted by Paul Anastas and John C. Warner. Industrial scale production often follows processes patented and implemented by firms such as BASF, ExxonMobil, Shell, and Dow Chemical Company.

Types and Examples

Representative classes and examples appear across chemical literature: inorganic salts like sodium chloride exemplified in texts by Humphry Davy; oxides such as silicon dioxide studied at Bell Labs; acids and bases discussed by Svante Arrhenius; organic small molecules like benzene detailed by August Kekulé; polymers like polyethylene developed at Imperial Chemical Industries; coordination compounds such as cisplatin associated with Alfred Werner; organometallic catalysts connected to Heidegger-era industrial chemistry and modern researchers like John B. Goodenough for energy materials. Biochemical compounds—amino acids, nucleotides, lipids—feature centrally in work by James Watson, Francis Crick, Rosalind Franklin, and Frederick Sanger.

Applications and Uses

Compounds enable applications across sectors championed by institutions and companies: pharmaceuticals produced by Pfizer, GlaxoSmithKline, Roche; agrochemicals developed at Syngenta and Monsanto; polymers and plastics manufactured by Dow Chemical Company and Bayer MaterialScience; specialty materials in electronics by Intel and Samsung; energy storage materials researched at Argonne National Laboratory and Lawrence Berkeley National Laboratory; catalysts used in petrochemical refining by ExxonMobil; analytical reagents supplied by Sigma-Aldrich. Compounds are integral to medical diagnostics at Mayo Clinic and Johns Hopkins Hospital, environmental monitoring by Environmental Protection Agency, and construction materials engineered by Skanska and Vinci.

Safety, Toxicity, and Regulation

Safety, toxicity, and regulatory oversight of compounds are governed by bodies such as EPA, ECHA, FDA, WHO, OSHA, and legislations like REACH, Toxic Substances Control Act, and Clean Air Act. Toxicological evaluation follows protocols from organizations including OECD and NIH, using assays developed at CDC and National Toxicology Program. Laboratory safety practices trace to standards promulgated by American Chemical Society and institutional biosafety committees at universities like Yale University and Columbia University, while industrial hygiene and emergency response procedures are coordinated with FEMA and local agencies.

Category:Chemistry