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Symbols, Terminology, and Nomenclature
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
RPH2, R2PH and R3P (R not equal to H) are called primary, secondary and tertiary phosphines, respectively. [5] Phosphonium compounds - Salts (and hydroxides) [R4P]+X- containing tetracoordinate phosphonium ion and the associated anion. [5] Phosphonium ylides - Compounds having the structure R3P+C-R2 R3P=CR2. Also known as Wittig reagents. [5] Phosphorescence - The process by which a molecule is excited by light to a higher electronic state and then undergoes a radiationless transition to a state of different multiplicity from which it decays, after some delay, to the ground state. The emitted light is normally of longer wavelength than the exciting light because vibrational energy has been dissipated. Photoelectric effect - The complete absorption of a photon by a solid with the emission of an electron. Photon - An elementary particle of zero mass and spin 1. The photon is involved in electromagnetic interactions and is the quantum of electromagnetic radiation. Photon stimulated desorption (PSD) - See Techniques for Materials Characterization, page 12-1. Pinacols - Tetra(hydrocarbyl)ethane-1,2-diols, R2C(OH)C(OH)R2, of which the tetramethyl example is the simplest one and is itself commonly known as pinacol. [5] Pion - An elementary particle in the family of mesons. Pions have zero spin and may be neutral or charged. They participate in the strong interaction which holds the nucleus together. pK* - The negative logarithm (base 10) of an equilibrium constant K. For pKa, see Acid dissociation constant. Planck constant (h)* - The elementary quantum of action, which relates energy to frequency through the equation E = h. Planck distribution - See Black body radiation Planck function - A thermodynamic function defined by Y = -G/T, where G is Gibbs energy and T thermodynamic temperature. [2] Plasma - A highly ionized gas in which the charge of the electrons is balanced by the charge of the positive ions, so that the system as a whole is electrically neutral. Plasmon - A quantum associated with a plasma oscillation in the electron gas of a solid. Point group* - A group of symmetry operations (rotations, reflections, etc.) that leave a molecule invariant. Every molecular conformation can be assigned to a specific point group, which plays a major role in determining the spectrum of the molecule. Poise (P) - A non-SI unit of viscosity, equal to 0.1 Pa s. Poiseuille's equation - A formula for the rate of flow of a viscous fluid through a tube:
NaSH-HCl mediated reduction of sulfoxides into sulfides under organic solvent-free reaction conditions
Published in Green Chemistry Letters and Reviews, 2020
Several reductions by using reducing agents in combination with different catalysts have been reported including PPh3 (1.5 eq.) in the presence of up to 5 mol% of MoO2(O2)(phox)2 in THF and in DCE (17), boranes (2.5 eq.)/5 mol% of Zn(OTf)2 in toluene (18), 1,3-dithiane (1.1 eq.) in the presence of electrophilic bromine as catalyst (19), mercaptopropyl-functionalized silica gel in the presence of 2% of Mo catalyst in toluene (20), PPh3 (1.1 eq.) in the presence of 5 mol% of ionic-liquid-molybdenum complexes in ionic liquid/toluene (21), NaHSO3 (1.1 eq.)/10 mol% of I2 in chloroform (22), catecholborane (2 eq.)/5 mol% of Rh catalyst in C6D6 (23), pinacol (2 eq.)/2 mol% of MoO2Cl2(DMF)2 under solvent-free reaction conditions (24), several equivalents of glycerol in the presence of 2.5 mol% of MoO2Cl2–(DMF)2 (25), boranes/5 mol% of MoO2Cl2 (26), benzyl alcohol (1.25 eq.)/2 mol% of carbon-supported dioxo-molybdenum catalyst (27), excess of isopropanol/5 mol% of hydroxyapatite-supported ruthenium nanoparticles in toluene (28), and pinacolborane (2 eq.)/1 mol% of magnesium hydridotriphenylborate in THF (29).