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Product Code B271
Price $116.00 ex. VAT

4H-cyclopenta[2,1-b:3,4-b′]dithiophene, also known as CPDT, a rigid coplanar structure favouring π−π intermolecular interactions with good electron-donating properties, has been one of the most attractive building blocks for organic field effect transistors and organic electronics. The five-member ring in the middle also offer the function to have side-chain manipulation to enhance solubility in solutions for device fabrications, morphology and polymer processing. One of the intensively studied polymer for organic electrons, PCPDTBT, with the alternating CPDT and 2,1,3- benzothiadiazole (BT) units, has demonstrated device performance of PCE over 6% [5]

Recently, CPDT backboned polymer CPE-K has been incorporated as the hole transporting layer (HTL) in polymer/fullerene BHJ and provskite solar cells. The devices using CPE-K HTL show competitive performance compared with that using PEDOT:PSS HTL. As an alternative to PEDOT:PSS, the use of CPE-K as an organic hole transport material enables the formation of uniform perovskite films with complete surface coverage for an efficient, stable perovskite/fullerene planar heterojunction solar cell [1, 2]

4H-cyclopenta[2,1-b:3,4-b′]dithiophene is the intermediate for the synthesis of 4,4'-alkyl-cyclopenta[2,1-b:3,4-b′]dithiophene [6].

synthesis of 4,4'-alkyl-cyclopenta[2,1-b:3,4-b′]dithiophene
Synthesis of 4,4'-alkyl-cyclopenta[2,1-b:3,4-b′]dithiophene in aqueous solutions.

General Information

CAS number
Chemical formula C9H6S2
Molecular weight 178.27 g/mol


  • 4H-Cyclopenta[2,1-b:3,4-b']dithiophene
  • 4H-Thieno[3',2':4,5]cyclopenta[1,2-b]thiophene
  • 3,4-Dithia-7H-cyclopenta[a]pentalene
  • CPDT
Classification / Family Monomers, Building blocks, Heterocycles, Chemical synthesis for low-band gap polymers, Thiophene, Intermediates for high performance Organic Photovoltaics, OFETs, Polymer solar cells

Product Details

Purity >99%
Melting point 71.0 to 75.0°C
Appearance Off-white powder

Chemical Structure

Chemical structure of 4H-Cyclopenta[2,1-b:3,4-b']dithiophene CAS number 389-58-2
Chemical structure of 4H-Cyclopenta[2,1-b:3,4-b']dithiophene, CAS 389-58-2.

NMR Characterisation

1H NMR cyclopenta-bithiophene
1H NMR spectrum of 4H-Cyclopenta[2,1-b:3,4-b']dithiophene in CDCl( view full version)

MSDS Documentation

4H-Cyclopenta[1,2-b:5,4-b']dithiophene MSDS4H-Cyclopenta[1,2-b:5,4-b']dithiophene MSDS sheet

Literature and Reviews

  1. Conjugated polyelectrolyte hole transport layer for inverted-type perovskite solar cells, H. Choi et al., Nat. Commun., DOI: 10.1038/ncomms8348, 6, 7348 (2015)
  2. Conductive conjugated polyelectrolyte as hole-transporting layer for organic bulk heterojunction solar cells, H. Zhou, et al., Adv. Mater. , 26, 780–785(2014)
  3. Improved Photovoltaic Performance of a Semicrystalline Narrow Bandgap Copolymer Based on 4H-Cyclopenta[2,1-b:3,4- b′]dithiophene Donor and Thiazolo[5,4-d]thiazole Acceptor Units, S. V. Mierloo et al., Chem. Mater., 24, 587−593 (2012).
  4. Synthesis and characterization of a series of low-bandgap copolymers based on cyclopenta[2,1-b:3,4-b']dithiophene and thienopyrroledione for photovoltaic applications, Y-R. Hong et al., Solar Energy Materials & Solar Cells 102, 58–65 (2012)
  5. Alternating Copolymers of Cyclopenta[2,1-b;3,4-b´]dithiophene and Thieno[3,4-c]pyrrole-4,6-dione for High-Performance Polymer Solar Cells, Z. Li, et al., Adv. Func. Mater., 21, 3331–3336(2011)
  6. Highly efficient and facile alkylation of 4Hcyclopenta-[2,1-b:3,4-b0]dithiophene in water, T. B. Raju et al., RSC Adv., 4, 37738 (2014).

To the best of our knowledge the information provided here is accurate. However, Ossila assume no liability for the accuracy of this page. The values provided are typical at the time of manufacture and may vary over time and from batch to batch. All products are for laboratory and research and development use only, and may not be used for any other purpose including health care, pharmaceuticals, cosmetics, food or commercial applications.

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