Beer and Lambert’s Law is a fundamental principle in spectroscopy that relates the absorption of light by a medium to its concentration and path length. It is widely used in analytical chemistry, physics, and biochemistry to quantify the concentration of analytes in solution. Statement of Beer-Lambert Law The law states: A = ϵ ⋅ c … Read more
The absorption spectrum of a molecule represents how it absorbs light across various wavelengths. The environment of a molecule, particularly the solvent it is dissolved in, plays a crucial role in influencing its electronic transitions and, consequently, its absorption spectrum. The solvent can shift the absorption maxima, alter the intensity of absorption bands, and even … Read more
Spectral shifts refer to changes in the position of the absorption or emission peaks of a molecule in a spectrum, often resulting from changes in the molecule’s environment, structure, or interactions. These shifts occur in response to variations in solvent polarity, pH, temperature, or the presence of substituents. Types of Spectral Shifts 1. Bathochromic Shift … Read more
An auxochrome is a functional group that does not itself absorb light in the visible spectrum but, when attached to a chromophore, modifies the chromophore’s ability to absorb light. It enhances the absorption intensity and often shifts the wavelength of maximum absorption (λmax)of the chromophore. Characteristics of Auxochromes 1. Functional Groups: Auxochromes typically contain lone … Read more
A chromophore is a part of a molecule responsible for its color by absorbing light in the ultraviolet (UV), visible, or infrared (IR) regions of the electromagnetic spectrum. It contains electrons that undergo electronic transitions when exposed to light of specific wavelengths, resulting in absorption. Characteristics of Chromophores 1. Conjugated Systems: Chromophores often contain conjugated … Read more
Electronic transitions are the movements of electrons between energy levels (orbitals) in a molecule or atom when they absorb or emit energy, such as photons of light. These transitions form the basis of techniques like UV-visible spectroscopy and are critical in understanding the optical and electronic properties of materials. Types of Electronic Transitions Electronic transitions … Read more
Introduction UV-Visible spectroscopy is an analytical technique that measures the absorption or reflectance of ultraviolet (UV) and visible light (200–800 nm) by a substance. It is widely used for quantitative and qualitative analysis of molecules in chemistry, biochemistry, and materials science. Principle of UV-Visible Spectroscopy The technique is based on the absorption of light energy, … Read more
