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Product Code B2321-10g
Price £110 ex. VAT

A fluorinated salicylic acid building block

A metal chelating agent and building block for fluorescence immunoassay, pH sensors and APIs


Specifications | MSDS | Literature and Reviews


5-Fluorosalicylic acid (CAS number 345-16-4), also known as 5-fluoro-2-hydroxybenzoic acid, has a fluorine substituent at 5-position and a hydroxyl group at 2-position. As an ortho-hydroxybenzoic acid, 5-fluorosalicylic acid is a good chelating agent. It forms highly fluorescent ternary complexes with terbium (Tb3+) that are employed in immunoassay. 5-Fluorosalicylic acid binds to copper (Cu2+) generating three isomers. Each isomer is formed predominantly depending on the pH value. Thus, 5-fluorosalicylic acid-copper complexes can be used for pH sensors. A flexible trifurcate titanium with 5-fluorosalicylic acid metalloligand can encapsulate silver nanoclusters in tetrahedral geometry. The metalloligand induces spatial growth and stability to the nanoclusters in non-linear optical and photoluminescent applications.

5-Fluorosalicylic acid is also used as a building block for active pharmaceutical ingredients (APIs) such as fluorinated deferasirox for chronic iron overload.

Multiple functional groups

Multiple functional groups

For facile synthesis

Fluorinated building block

Fluorinated salicylic acid building block

For drug discovery, metal complexes and dyes

Worldwide shipping for 345-16-4

Worldwide shipping

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High purity 345-16-4

High purity

>98% High purity

General Information


CAS Number 345-16-4
Chemical Formula C7H5FO3
Full Name 5-Fluorosalicylic acid
Molecular Weight 156.11 g/mol
Synonyms 5-Fluoro-2-hydroxybenzoic acid, 2-Hydroxy-5-fluorobenzoic acid
Classification / Family Fluorinated building block, Ligands, Fluorescence immunoassay, APIs, Sensors

Chemical Structure


5-Fluorosalicylic acid chemical structure, CAS 345-16-4
5-Fluorosalicylic acid chemical structure, CAS 345-16-4

Product Details


Purity 98%
Melting Point Tm = 177 – 179 °C 
Appearance Pale beige powder

MSDS Documentation


5-Fluorosalicylic acid5-Fluorosalicylic acid MSDS Sheet

Literature and Reviews


  1. Complexation of 5-fluorosalicylic acid with copper(II): a pH-potentiometric, UV–vis spectroscopic, and electron spin resonance study by the two-dimensional simulation of spectra, T. Szabó-Plánka et al., J. Inorg. Biochem., 102, 101–109 (2008); DOI: 10.1016/j.jinorgbio.2007.07.019.
  2. Enzymatically amplified time-resolved fluorescence immunoassay with terbium chelates, T. Christopoulos et al., Anal. Chem., 64(4), 342–346(1992); DOI: 10.1021/ac00028a004.
  3. Tetrahedral geometry induction of stable Ag-Ti nanoclusters by flexible trifurcate TiL3 metalloligand, M.-Y. Gao et al., J. Am. Chem. Soc., 142(29), 12784–12790(2020); DOI: 10.1021/jacs.0c05199.
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