Hypsochromic shift

Change in a molecule's spectral band position to a shorter wavelength

In spectroscopy, hypsochromic shift is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a shorter wavelength. Because the blue color in the visible spectrum has a shorter wavelength than most other colors, this effect is also commonly called a blue shift. It should not be confused with a bathochromic shift, which is the opposite process – the molecule's spectra are changed to a longer wavelength.

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