Lmol1cm1

Lmol1cm1 is a notation representing the molar absorptivity, also known as the molar extinction coefficient, with the conventional units of L mol^-1 cm^-1. In other words, it denotes how strongly a chemical species absorbs light at a specific wavelength in a solution, per mole of solute per liter of solution and per centimeter of optical path.

In practical terms, the quantity is used in Beer-Lambert law, A = ε c l, where A is the absorbance (dimensionless), ε is the molar absorptivity in L mol^-1 cm^-1, c is the solute concentration in mol L^-1, and l is the path length of the light through the sample in centimeters. Because c is in moles per liter and l is in centimeters, ε converts these into a unitless absorbance. The same coefficient can also be expressed as M^-1 cm^-1, since M stands for molarity (mol L^-1).

Molar absorptivity is specific to a particular substance at a given wavelength, and it can depend on temperature and solvent. It is a fundamental parameter in quantitative spectroscopy, used to determine concentrations of solutions from measured absorbance. Typical values vary widely between substances and wavelengths and are often reported in reference tables or determined experimentally.

Limitations include deviations from Beer-Lambert behavior at high concentrations, strong scattering, or interactions between solute molecules. Under such conditions, absorbance may no longer scale linearly with concentration or path length, and corrections or alternative methods may be required.