A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell.
Solvation describes the interaction of solvent with dissolved molecules. Both ionized and uncharged molecules interact strongly with solvent, and the strength and nature of this interaction influence many properties of the solute, including solubility, reactivity, and color, as well as influencing the properties of the solvent such as the viscosity and density. In the process of solvation, ions are surrounded by a concentric shell of solvent. Solvation is the process of reorganizing solvent and solute molecules into solvation complexes. Solvation involves bond formation, hydrogen bonding, and van der Waals forces. Solvation of a solute by water is called hydration.
In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end.
Dimethylformamide is an organic compound with the formula (CH3)2NC(O)H. Commonly abbreviated as DMF (although this initialism is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by sparging samples with an inert gas such as argon or by sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions.
(E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula C6H5CH=CHC6H5. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene. Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to cis-stilbene photochemically, and further reacted to produce phenanthrene.
In chemistry, solvatochromism is the phenomenon observed when the colour due to a solute is different when that solute is dissolved in different solvents.
In chemistry a donor number (DN) is a quantitative measure of Lewis basicity. A donor number is defined as the negative enthalpy value for the 1:1 adduct formation between a Lewis base and the standard Lewis acid SbCl5 (antimony pentachloride), in dilute solution in the noncoordinating solvent 1,2-dichloroethane with a zero DN. The units are kilocalories per mole for historical reasons. The donor number is a measure of the ability of a solvent to solvate cations and Lewis acids. The method was developed by V. Gutmann in 1976. Likewise Lewis acids are characterized by acceptor numbers (AN, see Gutmann–Beckett method).
The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes: the freshly prepared colourless solution slowly turns an amber colour, then suddenly changes to a very dark blue. This slowly fades to colourless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine.
The proton affinity of an anion or of a neutral atom or molecule is the negative of the enthalpy change in the reaction between the chemical species concerned and a proton in the gas phase:
Tin(IV) iodide, also known as stannic iodide, is the chemical compound with the formula SnI4. This tetrahedral molecule crystallizes as a bright orange solid that dissolves readily in nonpolar solvents such as benzene.
In organic chemistry, the Claisen–Schmidt condensation is the reaction between an aldehyde or ketone having an α-hydrogen with an aromatic carbonyl compound lacking an α-hydrogen. This reaction is named after two of its pioneering investigators Rainer Ludwig Claisen and J. G. Schmidt, who independently published on this topic in 1880 and 1881. An example is the synthesis of dibenzylideneacetone ( -1,5-diphenylpenta-1,4-dien-3-one).
A wash bottle is a squeeze bottle with a nozzle, used to rinse various pieces of laboratory glassware, such as test tubes and round bottom flasks.
Brooker's merocyanine is an organic dye belonging to the class of merocyanines.
Tetraphenylporphyrin, abbreviated TPP or H2TPP, is a synthetic heterocyclic compound that resembles naturally occurring porphyrins. Porphyrins are dyes and cofactors found in hemoglobin and cytochromes and are related to chlorophyll and vitamin B12. The study of naturally occurring porphyrins is complicated by their low symmetry and the presence of polar substituents. Tetraphenylporphyrin is hydrophobic, symmetrically substituted, and easily synthesized. The compound is a dark purple solid that dissolves in nonpolar organic solvents such as chloroform and benzene.
2-Nitrobenzaldehyde is an organic aromatic compound containing a nitro group ortho to formyl. 2-Nitrobenzaldehyde once was produced as an intermediate in the synthesis of the popular dye Indigo.
The blue bottle experiment is a color-changing redox chemical reaction. An aqueous solution containing glucose, sodium hydroxide, methylene blue is prepared in a closed bottle containing some air. Upon standing, it spontaneously turns from blue to colorless due to reduction of methylene blue by the alkaline glucose solution. However, shaking the bottle oxidizes methylene blue back into its blue form. With further shaking, this color-change cycle can be repeated many times. This experiment is a classic chemistry demonstration that can be used in laboratory courses as a general chemistry experiment to study chemical kinetics and reaction mechanism. The reaction also works with other reducing agents besides glucose and other redox indicator dyes besides methylene blue.
In chemistry, solvent effects are the influence of a solvent on chemical reactivity or molecular associations. Solvents can have an effect on solubility, stability and reaction rates and choosing the appropriate solvent allows for thermodynamic and kinetic control over a chemical reaction.
Glyoxal-bis(mesitylimine) is an organic compound with the formula H2C2(NC6H2Me3)2 (Me = methyl). It is a yellow solid that is soluble in organic solvents. It is classified as a diimine ligand. It is used in coordination chemistry and homogeneous catalysis. It is synthesized by condensation of 2,4,6-trimethylaniline and glyoxal. In addition to its direct use as a ligand, it is a precursor to imidazole precursors to the popular NHC ligand called IMes.
The nylon rope trick is a scientific demonstration that illustrates some of the fundamental chemical principles of step-growth polymerization and provides students and other observers with a hands-on demonstration of the preparation of a synthetic polymer.
3-Benzoxepin is an annulated ring system with an aromatic benzene ring and a non-aromatic, unsaturated, oxygen-containing seven-membered heterocyclic oxepin. The first synthesis was described by Karl Dimroth and coworkers in 1961. It is one of the three isomers of the benzoxepins.
