Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

IR Spectrometers

IR Spectrometers

There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...

Infrared (IR) Spectroscopy: Overview

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 Spectroscopy: Molecular Vibration Overview

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...

UV–Vis Spectrometers

UV–Vis Spectrometers

The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell. Samples for...

Spectrophotometry: Introduction

Spectrophotometry: Introduction

Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material.
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...

Applications of IR Spectroscopy: Overview

Applications of IR Spectroscopy: Overview

The non-destructive nature and ability to provide valuable chemical information make IR spectroscopy a versatile technique with broad applications in various scientific and industrial fields. IR spectroscopy is commonly used to identify and characterize organic and inorganic compounds. It provides information about the functional groups present in a molecule and the bonding between atoms. This helps in the structural elucidation of compounds during organic synthesis, pharmaceutical research,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Electric-field induced effects in acetylcholinesterase.

Neurochemistry international·2010

Same author

Infared diode laser double-beam spectrometer.

Applied optics·2010

Same author

Long path cell for perkin-elmer model 225 spectrophotometer.

Applied optics·2010

Same author

Spectropolarimeter for the Infrared (2-8 micro).

Applied optics·2010

Same author

Quantum chemistry predicted correlations between geometric isomerism (conformation) of -OH and =NH substituents and typical group frequencies of nucleic acid bases: cytosine.

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy·2001

Same author

Interfacial adsorption and aggregation associated changes in secondary structure of human calcitonin monitored by ATR-FTIR spectroscopy.

Biochemistry·1994

Search research articles

Related Experiment Video

Updated: Jun 16, 2026

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Modulated excitation infrared spectrophotometer.

U P Fringeli, H H Günthard

|January 23, 2010

Summary

A new infrared spectrophotometer detects photoinduced transients using modulated excitation. This instrument measures transient species kinetics, distinguishing four pyrocatechol photoproducts with lifetimes from 1 to 40 milliseconds.

Area of Science:

Spectroscopy
Photochemistry
Chemical Kinetics

Background:

Photoinduced transient species are crucial in understanding photochemical reactions.
Accurate measurement of their lifetimes and kinetics is essential for mechanistic studies.
Existing methods may have limitations in sensitivity or spectral range for certain transient species.

Purpose of the Study:

To design and construct a novel modulated excitation infrared spectrophotometer.
To enable the detection of photoinduced transients within the 3000-4000 cm(-1) spectral range.
To investigate the kinetics of transient species with lifetimes from 10(-1) to 10(-5) seconds.

Main Methods:

Utilized modulated excitation technique for enhanced sensitivity in infrared spectroscopy.

More Related Videos

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Published on: October 17, 2016

Related Experiment Videos

Last Updated: Jun 16, 2026

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Published on: October 17, 2016

Developed an instrument capable of detecting photoinduced transients.

Employed amplitude and phase measurements for kinetic information extraction.

Investigated single and double modulation strategies for optimal performance.

Main Results:

Successfully designed and constructed a modulated excitation infrared spectrophotometer.
Demonstrated the instrument's capability to detect photoinduced transients.
Identified four transient photoproducts of pyrocatechol.
Determined estimated lifetimes for these photoproducts ranging from 1 msec to 40 msec, distinguishable by phase measurements.

Conclusions:

The developed modulated excitation infrared spectrophotometer is effective for detecting and characterizing photoinduced transients.
The instrument provides valuable kinetic information through amplitude and phase measurements.
This technology advances the study of transient species in photochemistry and related fields.