Order Code: B261
MSDS sheet


(excluding Taxes)


General Information

CAS number
Chemical formula C10H4O2S2
Molecular weight 220.26 g/mol


  • Benzo[1,2-b:4,5-b']bisthiophene-4,8-dione
  • Thieno[2,3-f][1]benzothiophene-4,8-dione
Classification / Family

Thiophenes, Monomers, Building blocks, Carbazoles, Heterocycles, Polymer synthesis, Semiconductor synthesis, Intermediates for high performance, Organic Photovoltaics

Product Details

Purity >99%
Melting point 260-263°C
Apperance Yellow powder

Chemical Structure

chemical structure of Benzo-dithiophene-dione cas number 32281-36-0
Chemical structure of Benzo[1,2-b:4,5-b']dithiophene-4,8-dione. CAS number 32281-36-0; Chemical formula C10H4O2S2.



Benzo[1,2-b:4,5-b’]dithiophene is a planar symmetrical molecular structure of the thiophene derivative, enabling a better π-π stacking and good electron delocalization that encourages charge transport. In recent years, it has been intensively studied for the application of OFETs and OPVs. The incorporation of a low-band-gap unit into the benzo[1,2-b:4,5-b’]dithiophene unit could potentially result in a red-shifted absorption due to its electron-rich properties. Benzo[1,2-b:4,5-b’]dithiophene can be chemically modified to fine-tune its chemical structure and electron properties (e.g. band gap), energy levels, and charge mobility of the small molecule/polymers of interest (at a molecular level).

Benzo[1,2-b:4,5-b’]dithiophene (BDT) backboned polymers or small molecules thus provides a relatively better device performance. The following is a good example of a finely tuned structure being synthesised with Benzo[1,2-b:4,5-b’]dithiophene as a starting material.

synthesis of bis-2-ethylhexylthiophene-benzodithiophene using benzodithiophene as starting material
Synthesis of 4,8-Bis(2-ethylhexylthiophene)-benzo[1,2-b:4,5-b′]dithiophene using 4,8-benzo[1,2-b:4,5-b′]dithiophene and 2-ethylhexylthiophene as starting materials

NMR Characterisation


1H NMR of benzodithiophene-dionein CDCl3
1H NMR spectrum of Benzo[1,2-b:4,5-b']dithiophene-4,8-dione in CDCl3
 (view full version)

Literature and Reviews

  1. Utilizing alkoxyphenyl substituents for side-chain engineering of efficient benzo[1,2-b:4,5-b′]dithiophene-based small molecule organic solar cells, Z. Du, et al., Phys. Chem. Chem. Phys., 17, 17391-17398 (2015)
  2. Thieno[3,2‑b]thiophene-Substituted Benzo[1,2‑b:4,5‑b′]dithiophene as a Promising Building Block for Low Bandgap Semiconducting Polymers for High-Performance Single and Tandem Organic Photovoltaic Cells, J-H. Kim, et al., Chem. Mater., 26, 1234−1242 (2014)
  3. New Benzo[1,2-b:4,5-b’]dithiophene-Based Small Molecules Containing Alkoxyphenyl Side Chains for High Efficiency Solution-Processed Organic Solar Cells, Z. Du, et al., ChemSusChem, 7, 3319 – 3327 (2014)
  4. Polybenzo[1,2-b:4,5-b’]dithiophene Derivative with Deep HOMO Level and Its Application in High-Performance Polymer Solar Cells, L. Huo et al., Angew. Chem. Int. Ed., 49, 1500 –1503 (2010)
  5. Bandgap and Molecular Energy Level Control of Conjugated Polymer Photovoltaic Materials Based on Benzo[1,2-b:4,5-b′]dithiophene, J. Hou et al., Macromolecules, 41, 6012-6018 (2008)