3355-34-8

Basic information

• Product Name: 1,4-Phenylene
• Synonyms: p-Phenylene(8CI); 1,4-Dehydrobenzene; 1,4-Dibenzyne; 1,4-Didehydrobenzene; p-Benzyne;p-Didehydrobenzene
• CAS NO: 3355-34-8
• Molecular Formula: C6H4
• Molecular Weight: 76.0978
• Mol File: 3355-34-8.mol
• Article Data: 5

Chemical Properties

• CAS DataBase Reference: 1,4-Phenylene(CAS DataBase Reference)
• NIST Chemistry Reference: 1,4-Phenylene(3355-34-8)
• EPA Substance Registry System: 1,4-Phenylene(3355-34-8)

Safety Data

• Hazardous Substances Data: 3355-34-8(Hazardous Substances Data)

Usage

General Description

1,4-Phenylene, also known as para-phenylene or p-phenylene, is an organic compound distinguished by a phenyl ring, a cyclic group of atoms, connected at opposite ends to form a para orientation. It is a basic unit in the structure of various important polymers, including Kevlar and Nomex. The 1,4- designation refers to the linked carbon atoms on the phenyl ring. The compound itself is not typically isolated, but its derivatives are influential in the production of high-strength, fire-resistant materials, engineering plastics, and specific dyes. The specific arrangement of atoms in 1,4-phenylene allows for strong intermolecular interactions, which contribute to the remarkable strength and durability of the polymers.

Upstream product

• 16668-67-0 (Z)-hex-3-ene-1,5-diyne 
• 2396-01-2 phenyl radical 
• 71-43-2 benzene 

Downstream Products

• 16331-65-0 t-butoxide 
• 2396-01-2 phenyl radical 
• 21438-99-3 cyanomethanide 
• 56322-07-7 C₇H₄O₂^(1-) 
• 3474-12-2 dichloromethyl radical 
• 118364-73-1 dichlorocarbene^(1-) 
• 7440-44-0 pyrographite 
• 71-43-2 benzene 
• 16668-67-0 (Z)-hex-3-ene-1,5-diyne 

Relevant articles and documents

p-benzyne

A noble gas matrix at low temperature was used to investigate the photochemical behavior of diacetyl terephthaloyl diperoxide and dipropionyl terephthaloyl diperoxide as well as 1,4-diiodobenzene. All three photoreactions formed small quantities of a compound with IR absorption bands at 725 and 980 cm-1, which disappeared when the matrix was annealed. These bands correspond to the most intense of the calculated bands (B3LYP) for 1,4-didehydrobenzene (p-benzyne) (1). That decomposition of the peroxides in fact leads to 1 is confirmed by vapor-phase pyrolysis experiments in which (Z)-2 was obtained in high yield.

The Energy Well of Diradicals, V. - 1,3,5-Cyclohexatriene-1,4-diyl and 2,4-Cyclohexadiene-1,4-diyl

The energy profile of the Bergman rearrangement of (Z)-3-hexene-1,5-diyne (4) has been established from the NO and oxygen dependance of the trapping rate of the intermediate diradical 1 which leads to a heat of formation for 1,4-didehydrobenzene (1) of ΔH0f = 138.0 +/- 1.0 kcal * mol-1.By the same technique the heat of formation of 1,2,4-cyclohexatriene (2), generated by thermolysis of (Z)-1,3-hexadien-5-yne (10), gives ΔH0f = 105.1 +/- 1.0 kcal * mol-1 which indicates a high diradical character for 2. - Key Words: Diradicals / NO and O2 trapping / Heat of formation / Energy well / Rearrangements / Bergman cyclisation

Determination of the Singlet-Triplet Splitting and Electron Affinity of o-Benzyne by Negative Ion Photoelectron Spectroscopy

The photoelectron spectrum of the o-benzyne negative ion displays transitions to both the X/1A1 and a/3B2 states of the neutral molecule.Results yield adiabatic electron affinities of 0.560(10) and 0.551(10) eV for C6H4 and C6D4, respectively.These values are consistent with extrapolations from studies of larger strained cycloalkynes and imply that the lowest unoccupied MO of o-benzyne is primarly an antibonding acetylenic orbital.The o-benzyne singlet-triplet splitting is determined to be 37.7(6) kcal/mol.Several new vibrational frequencies for the neutral and anionic species are reported.