Related Experiment Video
Updated: Feb 22, 2026

On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes
Published on: August 5, 2016
Modeling Oil Shale Pyrolysis: High-Temperature Unimolecular Decomposition Pathways for Thiophene
AnGayle K Vasiliou1, Hui Hu2, Thomas W Cowell1
1Department of Chemistry and Biochemistry, Middlebury College , Middlebury, Vermont 05753, United States.
Abstract:
The thermal decomposition mechanism of thiophene has been investigated both experimentally and theoretically. Thermal decomposition experiments were done using a 1 mm × 3 cm pulsed silicon carbide microtubular reactor, C4H4S + Δ → Products. Unlike previous studies these experiments were able to identify the initial thiophene decomposition products. Thiophene was entrained in either Ar, Ne, or He carrier gas, passed through a heated (300-1700 K) SiC microtubular reactor (roughly ≤100 μs residence time), and exited into a vacuum chamber. The resultant molecular beam was probed by photoionization mass spectroscopy and IR spectroscopy. The pyrolysis mechanisms of thiophene were also investigated with the CBS-QB3 method using UB3LYP/6-311++G(2d,p) optimized geometries. In particular, these electronic structure methods were used to explore pathways for the formation of elemental sulfur as well as for the formation of H2S and 1,3-butadiyne. Thiophene was found to undergo unimolecular decomposition by five pathways: C4H4S → (1) S═C═CH2 + HCCH, (2) CS + HCCCH3, (3) HCS + HCCCH2, (4) H2S + HCC-CCH, and (5) S + HCC-CH═CH2. The experimental and theoretical findings are in excellent agreement.
More Related Videos
11:44Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry
Published on: March 6, 2016
11:28Biomass Conversion to Produce Hydrocarbon Liquid Fuel Via Hot-vapor Filtered Fast Pyrolysis and Catalytic Hydrotreating
Published on: December 25, 2016
Related Concept Videos
Benzene to Phenol via Cumene: Hock Process
Hydrolysis of Chlorobenzene to Phenol: Dow Process
Mass Spectrometry: Branched Alkane Fragmentation
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism