A perylene dye is a dye

Dye

A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....

 based on the perylene

Perylene

Perylene or perilene is a polycyclic aromatic hydrocarbon with the chemical formula C20H12, occurring as a brown solid. It or its derivatives may be carcinogenic, and it is considered to be a hazardous pollutant. In cell membrane cytochemistry, perylene is used as a fluorescent lipid probe...

 framework. Perylene itself consists of two naphthalene

Naphthalene

Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...

 units connected at the peri-position and in perylene homologues new naphthalene

Naphthalene

Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...

 units are added, forming compounds - or poly(peri-naphthalene)s - such as terrylene, quarterrylene. . In mono- and di-imide

Imide

In organic chemistry, an imide is a functional group consisting of two carbonyl groups bound to nitrogen. These compounds are structurally related to acid anhydrides. The relationship between esters and amides and between imides and anhydrides is analogous, the amine-derived groups are less reactive...

 derivatives solubility is greatly improved.

Perylene dyes are actively researched in academia for optoelectronic and photovoltaic devices, thermographic processes, energy-transfer cascades, light-emitting diode

Light-emitting diode

A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

s, and near-infrared-absorbing systems.

A bathochromic shift

Bathochromic shift

Bathochromic shift is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength ....

 of about 100 nm is recorded per additional naphthalene unit.

Pigments

Several perylene pigments have been developed for artist's paints :

• Perylene red
  Red
  Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
  
   (PR149), a middle red, between light and dark cadmium
  Cadmium
  Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
  
   red.
• Perylene maroon
  Maroon (color)
  Maroon is a dark red color.-Etymology:Maroon is derived from French marron .The first recorded use of maroon as a color name in English was in 1789.-Maroon :...
  
   (PR179), closed to alizarin crimson
  Alizarin
  Alizarin or 1,2-dihydroxyanthraquinone is an organic compound with formula that has been used throughout history as a prominent dye, originally derived from the roots of plants of the madder genus.Alizarin was used as a red dye for the English parliamentary "new model" army...
  
   (PR83).
• Perylene violet
  Violet (color)
  As the name of a color, violet is synonymous with a bluish purple, when the word "purple" is used in the common English language sense of any color between blue and red, not including either blue or red...
  
   (PV29)
• Perylene black
  Black
  Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
  
  (PBk31)