Bathochromic shift, a change in band position to a longer wavelength (lower frequency).

In the presence of ammonia salts, the bathochromic shifts increase.

This bathochromic shift is well known in regular conjugated compounds such as butadiene.

A bathochromic shift of about 100 nm is recorded per additional naphthalene unit.

A series of structurally related molecules in a substitution series can also show a bathochromic shift.

Bathochromic shift is typically demonstrated using a spectrophotometer, colorimeter, or spectroradiometer.

As molecules with higher conjugation levels undergo this bathochromic shift phenomenon, a part of the visible spectrum is absorbed.

The electronic transitions of molecules in solution can depend strongly on the type of solvent with additional bathochromic shifts or hypsochromic shifts.

However, according to Woodward's rules, bathochromic shifts often also happen suggesting the presence of delocalised π electrons arising from a conjugation between the benzene and vinyls groups.

An auxochrome is known as a compound that produces a bathochromic shift, also known as red shift because it increases the wavelength of absorption, therefore moving closer to infrared light.

Bathochromic shift is a phenomenon seen in molecular spectra, not atomic spectra; it is thus more common to speak of the movement of the peaks in the spectrum rather than lines.

A J-aggregate is a type of dye with an absorption band that shifts to a longer wavelength (bathochromic shift) of increasing sharpness (higher absorption coefficient) when it aggregates under the influence of a solvent or additive or concentration as a result of supramolecular self-organisation.