Description
p-Terphenyl(PTP) is an aromatic hydrocarbon isomer, formed by three benzene rings in ortho position. Pure terphenyl is a white crystalline solid, insoluble in water. Though polychlorinated terphenyls were used as heat storage and transfer agents, p-terphenyl is currently under investigation as a material to be used in opto-electronic devices, such as organic LED devices (OLEDs) and currently used in laser dyes and sunscreen lotions. In particle physics it has been used as a wavelength shifter, exploiting its sensitivity to VUV radiation, to read out scintillation light from liquid Xenon. Pterphenyl has also been used as a doping component for liquid scintillators.
So far, p-terphenyl has not been used as main component of particle detectors due to its short Light Attenuation Length. As a matter of fact this property could be exploited when detecting low-energy charged particles in small areas, providing both energy and position measurement.
Chemical Properties
a White or light-yellow solid. The melting point is 213°C, boiling point is 383°C, 250°C (6kPa), flash point is 207°C, and relative density is 1.234 (0°C). Soluble in hot benzene, slightly soluble in ether and carbon disulfide, extremely insoluble in ethanol and acetic acid. 427℃ sublimation. p-Terphenyl can be separated from the by-products of biphenyl production.
Uses
p-Terphenyl is a specialty material, and may be used in ionized radiation detectors, nonpolar laser dye, and single molecule optical probe of scanning near-field microscopy.
Application
LCD Electronics: P-Terphenyl is one of the basic intermediates for preparing diphenyl LCD materials at present.
Organic synthesis: P-Terphenyl is the basic raw material for synthesizing antifungal cyclic peptide (4-carboxyl P–Terphenyl CTP) and diphenyl polyamide material 4, 4-（DCTP).
Fine chemical engineering: under radiation, P-Terphenyl will generate fluorescence, and thus it can be used as an organic scintillation reagent. It is used as an illuminant in scintillation counters and as a synthetic intermediate for laser dyes.
p-Terphenyl-Sensitized Photoreduction of CO2 with Cobalt and Iron Porphyrins. Interaction between CO and Reduced Metalloporphyrins
Definition
ChEBI: p-Terphenyl is a para-terphenyl that consists of benzene attached to two phenyl units at positions 1 and 4 respectively.
General Description
White or light-yellow needles or leaves. Mp: 212-213°C; bp 376°C. Density: 1.23 g cm-3. Insoluble in water. Soluble in hot benzene. Very soluble in hot ethyl alcohol. Usually shipped as a solid mixture with its isomers o-terphenyl and m-terphenyl that is used as a heat-transfer fluid.
Reactivity Profile
p-Terphenyl(92-94-4) is non-flammable but combustible (flash point: 410°C). Extremely stable thermally. Incompatible with strong oxidizing agents but not very reactive at room conditions.
Hazard
Toxic by ingestion and inhalation. Eye and
upper respiratory tract irritant.
Purification Methods
Crystallise p-terphenyl from nitrobenzene or trichlorobenzene. It is also purified by chromatography on alumina in a darkened room, using pet ether, and then crystallising from pet ether (b 40-60o) or pet ether/*benzene. It is a fluorophore for scintillation counting and has ex 286nm : em 343nm in DMF, and max 277nm (log 4.50). [Beilstein 5 IV 2483.]
