Related Experiment Video

Updated: Jun 16, 2026

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared
07:38

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

Published on: January 10, 2025

Infrared bulk and surface absorption by nearly transparent crystals

H B Rosenstock, D A Gregory, J A Harrington

    Applied Optics
    |February 19, 2010
    PubMed

    More Related Videos

    In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework11:38

    In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework

    Published on: February 1, 2020

    The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight10:27

    The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight

    Published on: October 11, 2016

    Related Concept Videos

    Infrared (IR) Spectroscopy: Overview01:09

    Infrared (IR) Spectroscopy: Overview

    When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
    Different compounds display unique properties due to their...
    IR Spectrum01:19

    IR Spectrum

    When infrared (IR) radiation passes through a molecule, the bonds stretch or bend by absorbing the radiation. This absorption creates the molecule's absorption spectrum, which is the plot of its percentage transmittance versus wavenumber.
    Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
    IR Spectrum Peak Intensity: Amount of IR-Active Bonds00:55

    IR Spectrum Peak Intensity: Amount of IR-Active Bonds

    When infrared radiation is passed through a molecule, absorption occurs if the molecule's vibration leads to a substantial change in its bond dipole moment. Transitions between vibrational energy levels, typically corresponding to infrared frequencies (4000–400 cm−1), allow absorption if the vibration significantly alters the dipole moment, making the molecule infrared active. The molecular bonds have different stretching and bending vibrations, resulting in various peaks with varying...
    Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview01:13

    Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview

    Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
    The ATR process begins by directing a beam...
    IR Spectroscopy: Molecular Vibration Overview01:24

    IR Spectroscopy: Molecular Vibration Overview

    When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
    Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
    IR Frequency Region: Fingerprint Region01:03

    IR Frequency Region: Fingerprint Region

    IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1.
    The...