Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H2. It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen each atom has one proton, one electron, and no neutrons.
The Miller–Urey experiment (or Miller experiment) was an experiment in chemical synthesis carried out in 1952 that simulated the conditions thought at the time to be present in the atmosphere of the early, prebiotic Earth. It is seen as one of the first successful experiments demonstrating the synthesis of organic compounds from inorganic constituents in an origin of life scenario. The experiment used water (H2O), methane (CH4), ammonia (NH3), hydrogen (H2), and an electric arc (the latter simulating lightning) and resulted in the production of amino acids.
Mechanochemistry is the initiation of chemical reactions by mechanical phenomena. Mechanochemistry thus represents a fourth way to cause chemical reactions, complementing thermal reactions in fluids, photochemistry, and electrochemistry. Conventionally mechanochemistry focuses on the transformations of covalent bonds by mechanical force. Not covered by the topic are many phenomena: phase transitions, dynamics of biomolecules, and sonochemistry.
Gabor A. Somorjai is a professor of chemistry at the University of California, Berkeley, and is a leading researcher in the field of surface chemistry and catalysis, especially the catalytic effects of metal surfaces on gas-phase reactions. For his contributions to the field, Somorjai won the Wolf Prize in Chemistry in 1998, the Linus Pauling Award in 2000, the National Medal of Science in 2002, the Priestley Medal in 2008, the 2010 BBVA Foundation Frontiers of Knowledge Award in Basic Science and the NAS Award in Chemical Sciences in 2013. In April 2015, Somorjai was awarded the American Chemical Society's William H. Nichols Medal.
Sulfur monoxide is an inorganic compound with formula SO. It is only found as a dilute gas phase. When concentrated or condensed, it converts to S2O2 (disulfur dioxide). It has been detected in space but is rarely encountered intact otherwise.
Water splitting is the chemical reaction in which water is broken down into oxygen and hydrogen:
In chemistry, a transition metal pincer complex is a type of coordination complex with a pincer ligand. Pincer ligands are chelating agents that binds tightly to three adjacent coplanar sites in a meridional configuration. The inflexibility of the pincer-metal interaction confers high thermal stability to the resulting complexes. This stability is in part ascribed to the constrained geometry of the pincer, which inhibits cyclometallation of the organic substituents on the donor sites at each end. In the absence of this effect, cyclometallation is often a significant deactivation process for complexes, in particular limiting their ability to effect C-H bond activation. The organic substituents also define a hydrophobic pocket around the reactive coordination site. Stoichiometric and catalytic applications of pincer complexes have been studied at an accelerating pace since the mid-1970s. Most pincer ligands contain phosphines. Reactions of metal-pincer complexes are localized at three sites perpendicular to the plane of the pincer ligand, although in some cases one arm is hemi-labile and an additional coordination site is generated transiently. Early examples of pincer ligands were anionic with a carbanion as the central donor site and flanking phosphine donors; these compounds are referred to as PCP pincers.
Jack David Dunitz FRS was a British chemist and widely known chemical crystallographer. He was Professor of Chemical Crystallography at the ETH Zurich from 1957 until his official retirement in 1990. He held Visiting Professorships in the United States, Israel, Japan, Canada, Spain and the United Kingdom.
Sir David William Cross MacMillan is a Scottish chemist and the James S. McDonnell Distinguished University Professor of Chemistry at Princeton University, where he was also the chair of the Department of Chemistry from 2010 to 2015. He shared the 2021 Nobel Prize in Chemistry with Benjamin List "for the development of asymmetric organocatalysis". MacMillan used his share of the $1.14 million prize to establish the May and Billy MacMillan Foundation.
Arieh Warshel is an Israeli-American biochemist and biophysicist. He is a pioneer in computational studies on functional properties of biological molecules, Distinguished Professor of Chemistry and Biochemistry, and holds the Dana and David Dornsife Chair in Chemistry at the University of Southern California. He received the 2013 Nobel Prize in Chemistry, together with Michael Levitt and Martin Karplus for "the development of multiscale models for complex chemical systems".
Chloroauric acid is an inorganic compound with the chemical formula H[AuCl4]. It forms hydrates H[AuCl4]·nH2O. Both the trihydrate and tetrahydrate are known. Both are orange-yellow solids consisting of the planar [AuCl4]− anion. Often chloroauric acid is handled as a solution, such as those obtained by dissolution of gold in aqua regia. These solutions can be converted to other gold complexes or reduced to metallic gold or gold nanoparticles.
Daniel George Nocera is an American chemist, currently the Patterson Rockwood Professor of Energy in the Department of Chemistry and Chemical Biology at Harvard University. He is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. In 2006 he was described as a "major force in the field of inorganic photochemistry and photophysics". Time magazine included him in its 2009 list of the 100 most influential people.
Graham R. Fleming is a professor of chemistry at the University of California, Berkeley and member of the Kavli Energy NanoScience Institute based at UCB.
Zhenan Bao is a chemical engineer. She serves as K. K. Lee Professor of Chemical Engineering at Stanford University, with courtesy appointments in Chemistry and Material Science and Engineering. She served as the Department Chair of Chemical Engineering from 2018 to 2022. Bao is known for her work on organic field-effect transistors and organic semiconductors, for applications including flexible electronics and electronic skin.
Bernard Lucas Feringa is a Dutch synthetic organic chemist, specializing in molecular nanotechnology and homogeneous catalysis. He is the Jacobus van 't Hoff Distinguished Professor of Molecular Sciences, at the Stratingh Institute for Chemistry, University of Groningen, Netherlands, and an Academy Professor of the Royal Netherlands Academy of Arts and Sciences. He was awarded the 2016 Nobel Prize in Chemistry, together with Sir J. Fraser Stoddart and Jean-Pierre Sauvage, "for the design and synthesis of molecular machines".
Jillian Lee Dempsey is an American inorganic chemist and the Bowman and Gordon Gray Distinguished Term Professor at the University of North Carolina at Chapel Hill. Currently, her work focuses on proton-coupled electron transfer, charge transfer events, and quantum dots. She is the recipient of numerous awards for rising stars of chemistry, including most recently a 2016 Alfred P. Sloan Research Fellowship and a 2016 Air Force's Young Investigator Research Program (YIP).
Uri Banin is an Israeli nanotechnologist and physical chemist and a professor at the Hebrew University of Jerusalem, currently holding the Alfred & Erica Larisch Memorial Chair at the Institute of Chemistry. He is recognized as one of the pioneers of nanoscience in Israel.
Xile Hu is a Swiss chemist specialized in catalysis. He is a professor in chemistry at EPFL and leads the Laboratory of Inorganic Synthesis and Catalysis at the School of Basic Sciences.
Metal-ligand cooperativity (MLC) is a mode of reactivity in which a metal and ligand of a complex are both involved in the bond breaking or bond formation of a substrate during the course of a reaction. This ligand is an actor ligand rather than a spectator, and the reaction is generally only deemed to contain MLC if the actor ligand is doing more than leaving to provide an open coordination site. MLC is also referred to as "metal-ligand bifunctional catalysis." Note that MLC is not to be confused with cooperative binding.
Carbon-carbon bond activation refers to the breaking of carbon-carbon bonds in organic molecules. This process is an important tool in organic synthesis, as it allows for the formation of new carbon-carbon bonds and the construction of complex organic molecules. However, C–C bond activation is challenging mainly for the following reasons: (1) C-H bond activation is a competitive process of C-C activation, which is both energetically and kinetically more favorable; (2) the accessibility of the transition metal center to C–C bonds is generally difficult due to its 'hidden' nature; (3) relatively high stability of the C–C bond. As a result, in the early stage, most examples of C-C activation are of stringed ring systems, which makes C-C activation more favorable by increasing the energy of the starting material. However, C-C activation of unstrained C-C bonds has remained challenging until the recent two decades.
