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The Taft equation is a linear free energy relationship (LFER) used in physical organic chemistry in the study of reaction mechanisms and in the development of quantitative structure–activity relationships for organic compounds.
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. Polar molecules must contain one or more polar bonds due to a difference in electronegativity between the bonded atoms.
Positive solvatochromism corresponds to a bathochromic shift (or red shift) with increasing solvent polarity. An example of positive solvatochromism is provided by 4,4'-bis(dimethylamino)fuchsone, which is orange in toluene, red in acetone. The main value of the concept of solvatochromism is the context it provides to predict colors of solutions.
This Wikipedia page provides a comprehensive list of boiling and freezing points for various solvents.
(However, PE only dissolves at temperatures well above 100 °C.) Poly(styrene) has a solubility parameter of 9.1 cal 1/2 cm −3/2, and thus ethyl acetate is likely to be a good solvent. Nylon 6,6 has a solubility parameter of 13.7 cal 1/2 cm −3/2, and ethanol is likely to be the best solvent of those tabulated. However, the latter is polar ...
[1]: 244 It is defined as the change in orientation of monochromatic plane-polarized light, per unit distance–concentration product, as the light passes through a sample of a compound in solution. [2]: 2–65 Compounds which rotate the plane of polarization of a beam of plane polarized light clockwise are said to be dextrorotary, and ...
The polar surface area (PSA) or topological polar surface area (TPSA) of a molecule is defined as the surface sum over all polar atoms or molecules, primarily oxygen and nitrogen, also including their attached hydrogen atoms. PSA is a commonly used medicinal chemistry metric for the
In physical organic chemistry, the Grunwald–Winstein equation is a linear free energy relationship between relative rate constants and the ionizing power of various solvent systems, describing the effect of solvent as nucleophile on different substrates. The equation, which was developed by Ernest Grunwald and Saul Winstein in 1948, could be ...