The key difference between bathochromic shift and hypsochromic shift is that bathochromic shift is a longer wavelength shift, whereas hypsochromic shift is a shorter wavelength shift.
Bathochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength. The hypsochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule that is exposed to a shorter wavelength.
CONTENTS
1. Overview and Key Difference
2. What is Bathochromic Shift
3. What is Hypsochromic Shift
4. Bathochromic Shift vs Hypsochromic Shift in Tabular Form
5. Summary – Bathochromic Shift vs Hypsochromic Shift
What is Bathochromic Shift?
Bathochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength. Since the red color in the visible spectrum has a long wavelength, we can call this effect the redshift.
Figure 01: Red Shift and Blue Shift
Bathochromic shift can take place due to a change in environmental conditions, such as a change in solvent polarity, which can result in a solvatochromism. Moreover, a series of structurally-related molecules that occurs in a substitution series can also display a bathochromic shift. We can find this phenomenon in molecular spectra but not in atomic spectra. Therefore, it is more common when considering the movement of the peaks in the spectrum rather than the lines. We can easily detect bathochromic shift with the use of a spectrophotometer, colorimeter, and spectroradiometer.
What is Hypsochromic Shift?
Hypsochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule that is exposed to a shorter wavelength. Since the visible spectrum shows a shorter wavelength for the blue color, we can call this shift blue shift.
Hypsochormic shift can happen due to a change in the environmental conditions, such as a change in solvent polarity that can result in solvatochromism. Moreover, a series of structurally-related molecules that occurs in a substitution series can also display a hypsochromic shift. We can find this phenomenon in molecular spectra but not in atomic spectra. Therefore, it is more common when considering the movement of the peaks in the spectrum rather than the lines. E.g. beta-acylpyrrole can show a hypsochromic shift of 30-40 nm when compared with alpha-acypyrroles.
What is the Difference Between Bathochromic Shift and Hypsochromic Shift?
Bathochromic shift and hypsochromic shift are important analytical concepts. The key difference between bathochromic shift and hypsochromic shift is that bathochromic shift is a longer wavelength shift, whereas hypsochromic shift is a shorter wavelength shift. Bathochromic shift is known as redshift, while hypsochromic shift is known as blue shift. Moreover, the bathochromic shift has a lower frequency while the hypsochromic shift has a higher frequency.
The below infographic presents the differences between bathochromic shift and hypsochromic shift in tabular form for side by side comparison.
Summary – Bathochromic Shift vs Hypsochromic Shift
Bathochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength. The hypsochromic shift can be described as a change of spectral band positions in the absorption, reflectance, transmittance, or emission spectrum of a molecule that is exposed to a shorter wavelength. The key difference between bathochromic shift and hypsochromic shift is that bathochromic shift is a longer wavelength shift, whereas hypsochromic shift is a shorter wavelength shift.
Reference:
1. “Bathochromic Effect.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “Redshift blueshift” By Aleš Tošovský – Own work (CC BY-SA 3.0) via Commons Wikimedia