Perylenetetracarboxylic dianhydride (PTCDA) is an organic dye molecule and an

organic semiconductor Organic semiconductors are solids whose building blocks are pi-bonded molecules or polymers made up by carbon and hydrogen atoms and – at times – heteroatoms such as nitrogen, sulfur and oxygen. They exist in the form of molecular crystals or ...

. It is used as a precursor to a class of molecules known as

Rylene dye A rylene dye is a dye based on the rylene framework of naphthalene units linked in peri-positions. In homologues additional naphthalene units are added, forming compounds — or ''poly(peri-naphthalene)s'' — such as perylene, terrylene and qua ...

s, which are useful as

pigments A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

and dyes. It is a dark red solid with low solubility in aromatic solvents. The compound has attracted much interest as an organic semiconductor.

Structure

PTCDA consists of a

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, ...

core to which two

anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the pa ...

groups have been attached, one at either side. It occurs in two crystalline forms, α and β. Both have the P2₁/c

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

symmetry and a density of ca. 1.7 g/cm³, which is relatively high for organic compounds. Their lattice parameters are:

Self-assembly and films

Use

The main industrial use of PTCDA is as a precursor to

s.Hunger, K. and Herbst, W. (2012) "Pigments, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim. Greene, M. (2009) "Perylene Pigments", pp. 261–274 in High Performance Pigments, Wiley-VCH, Weinheim.

References

{{dyeing Perylene dyes Vat dyes Organic semiconductors