Rubrene (5,6,11,12-tetraphenyltetracene) is a red colored polycyclic aromatic hydrocarbon. Rubrene is used as a sensitiser in

chemoluminescence Chemiluminescence (also chemoluminescence) is the emission of light (luminescence) as the result of a chemical reaction. There may also be limited emission of heat. Given reactants A and B, with an excited intermediate ◊, : + -> lozenge - ...

and as a yellow light source in

lightstick A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light ...

Electronic properties

As an organic semiconductor, the major application of rubrene is in organic light-emitting diodes (OLEDs) and organic field-effect transistors, which are the core elements of flexible displays. Single-crystal transistors can be prepared using crystalline rubrene, which is grown in a modified zone furnace on a temperature gradient. This technique, known as physical vapor transport, was introduced in 1998. Rubrene holds the distinction of being the organic semiconductor with the highest carrier mobility, reaching 40 cm²/(V·s) for

holes A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of en ...

. This value was measured in OFETs prepared by peeling a thin layer of single-crystalline rubrene and transferring to a Si/SiO₂ substrate.

Crystal structure

Several

polymorph Polymorphism, polymorphic, polymorph, polymorphous, or polymorphy may refer to: Computing * Polymorphism (computer science), the ability in programming to present the same programming interface for differing underlying forms * Ad hoc polymorphi ...

s of rubrene are known. Crystals grown from vapor in vacuum can be monoclinic, triclinic, and

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a r ...

motifs. Orthorhombic crystals ( space group B_bam) are obtained in a closed system in a two-zone furnace at ambient pressure.

Synthesis

Rubrene is prepared by treating 1,1,3-Triphenyl-2-propyn-1-ol with thionyl chloride. : 3-chloro-1,1,3-triphenylpropa-1,2-diene

The resulting chloro allene undergoes

dimerization A dimer () (''wikt:di-, di-'', "two" + ''-mer'', "parts") is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, Covalent bond, covalent or Intermolecular force, intermolecular. Dimers also have significant im ...

and dehydrochlorination to give rubrene. : Rubrene synthesis

Redox properties

Rubrene, like other polycyclic aromatic molecules, undergoes redox reactions in solution. It oxidizes and reduces reversibly at 0.95 V and −1.37 V, respectively vs SCE. When the cation and anion are co-generated in an electrochemical cell, they can combine with annihilation of their charges, but producing an excited rubrene molecule that emits at 540 nm. This phenomenon is called electrochemiluminescence.

References

{{reflist Polycyclic aromatic hydrocarbons Organic semiconductors Fluorescent dyes