FREE shipping to on qualifying orders when you spend or more, processed by Ossila BV. All prices ex. VAT. Qualifying orders ship free worldwide! Fast, secure, and backed by the Ossila guarantee. It looks like you are visiting from , click to shop in or change country. Orders to the EU are processed by our EU subsidiary.

It looks like you are using an unsupported browser. You can still place orders by emailing us on, but you may experience issues browsing our website. Please consider upgrading to a modern browser for better security and an improved browsing experience.

Product Code B1501-1g
Price £72 ex. VAT

A versatile fluorinated indazole building block 

Used for the synthesis of semiconducting molecules and polymers in the application of OLEDs and OPVs

Specifications | MSDS | Literature and Reviews

4-Fluoro-1H-indazole (also known as 4-Fluoroindazole), CAS number 341-23-1, a fluorinated indazole heterocyclic aromatic compound and a powerful chromophore unit, consists of a fluoride substituent at 4-position with the pyrazole fused to a benzene ring. 4-Fluoro-1H-indazole can readily be further functionalized via nucleophilic aromatic substitution reactions.

Pyrazoles and indazoles have been extensively used pharmaceutical industry with  a variety of biological activities. Indazole is a highly conjugated molecule which expands its applications to dye-sensitized solar cells (DSSCs). Owing to the pyrazole moiety, 4-fluoro-1H-indazole can coordinate to metal centre (such as Ir, Ln and Eu) to form either heteroleptic or homoleptic triplet photosensitizers that have an efficient ligand to metal energy transfer process. The fluorine group in the molecule is electron deficient and can be used to tune the energy gap of the molecule/complex. This fluorinated indazole enable the intermolecular interaction including π−π stacking and H−F hydrogen/halogen bonding.

Multiple functional groups

Multiple functional groups

For facile synthesis

Fluorinated building block

Fluorinated indole building block

For semiconductors, dyes, and solar cells

Worldwide shipping for 341-23-1

Worldwide shipping

Quick and reliable shipping

High purity 341-23-1

High purity

>98% High purity

General Information

CAS Number 341-23-1
Chemical Formula C7H5FN2
Full Name 4-Fluoro-1H-indazole
Molecular Weight 136.13 g/mol
Synonyms 4-Fluoroindazole
Classification / Family Indazole derivatives, Fluorinated building blocks, Heterocyclic building blocks, Dyes, Semiconductor synthesis intermediates, OPVs

Chemical Structure

4-Fluoro-1H-indazole CAS 341-23-1
4-Fluoro-1H-indazole chemical structure, CAS 341-23-1

Product Details

Purity >98% (1H NMR)
Melting Point Tm = 130 °C - 134 °C
Appearance Yellow-green powder/crystals

MSDS Documentation

4-Fluoro-1H-indazole4-Fluoro-1H-indazole MSDS Sheet

Literature and Reviews

  1. Synthesis, electrochemical, photophysical, and photovoltaic properties of new fluorescent compounds: 3H-benzofuro [2,3-b]pyrazolo[4,3-f]quinoline, Z. Ghamati et al., Int. J. Energy Res., 45,7797–7805(2021); DOI: 10.1002/er.6363.
  2. New derivatives of indazole as electronically active materials, M. Cekaviciute et al., Dyes Pigm., 92, 654-658(2011); DOI:10.1016/j.dyepig.2011.05.021.
  3. Effective passivation of a high-voltage positive electrode by 5-hydroxy-1H-indazole additives, Y.-S. Kang et al., J. Mater. Chem. A, 2, 14628-14633(2014); DOI: 10.1039/c4ta01891e.

Return to the top