Chlorophenol red

Chlorophenol red

Names
Preferred IUPAC name 3,3-Bis(3-chloro-4-hydroxyphenyl)-2,1λ6-benzoxathiole-1,1(3H)-dione
Other names 3′,3′-Dichlorophenolsulfonaphthalein
Identifiers
CAS Number	4430-20-0  Y
3D model (JSmol)	Interactive image
ChemSpider	19293  N
ECHA InfoCard	100.022.382
EC Number	224-619-2
PubChem CID	20486
UNII	P3S5KH33EA  Y
CompTox Dashboard (EPA)	DTXSID4063450
InChI InChI=1S/C19H12Cl2O5S/c20-14-9-11(5-7-16(14)22)19(12-6-8-17(23)15(21)10-12)13-3-1-2-4-18(13)27(24,25)26-19/h1-10,22-23H N Key: WWAABJGNHFGXSJ-UHFFFAOYSA-N N InChI=1/C19H12Cl2O5S/c20-14-9-11(5-7-16(14)22)19(12-6-8-17(23)15(21)10-12)13-3-1-2-4-18(13)27(24,25)26-19/h1-10,22-23H Key: WWAABJGNHFGXSJ-UHFFFAOYAK
SMILES C1=CC=C2C(=C1)C(OS2(=O)=O)(C3=CC(=C(C=C3)O)Cl)C4=CC(=C(C=C4)O)Cl
Properties
Chemical formula	C19H12Cl2O5S
Molar mass	423.26 g·mol−1
Melting point	261 °C (502 °F; 534 K) [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Chlorophenol red(pH indicator)
below pH 5.4		above pH 6.8
5.4	⇌	6.8

Chlorophenol red is an indicator dye that changes color from yellow to violet in the pH range 5.4 to 6.8. ^[2] The pH of a substance is determined by taking the negative logarithm of the Hydronium ion concentration and the indictor changes color due to the dissociation of H⁺ ions. ^[3] The lambda max is at 572 nm. ^[4]

Properties and uses

The dissociation mechanism of chlorophenol red is similar to that of phenolphthalein meaning it can be used as a color indicator. The dissociation of hydroxyl and hydrogen atoms creates the dissociate scheme of chlorophenol red to change color from yellow to red. ^[5] The pH properties of chlorophenol red are used to selectively determine the amount of chlorine dioxide in drinking water. Chlorophenol red selectively reacts with 0.1–1.9 mg/L chlorine dioxide at pH 7. ^[6] The electrochemical properties of Chlorophenol red allows it to be a chromogenic label and can undergo oxidation creating several phenolic intermediates. The bacterial hydrolysis of a chlorophenol red labelled substrate produces chlorine retaining intermediates on electrodes. ^[7]

References

1. Haynes, p. 3.116
2. Haynes, p. 8.88
3. "pH Indicators". Chemistry LibreTexts. 2013-10-02. Retrieved 2021-03-14.
4. "Chlorophenol Red".
5. Hanai, Toshihiko (2016). "Quantitative Evaluation of Dissociation Mechanisms in Phenolphthalein and the Related Compounds". Journal of Computer Chemistry. 15: 13–21. doi: 10.2477/jccj.2015-0055 .
6. Sweetin, Deborah L.; Sullivan, Elizabeth; Gordon, Gilbert (1996-01-01). "The use of chlorophenol red for the selective determination of chlorine dioxide in drinking water". Talanta. 43 (1): 103–108. doi:10.1016/0039-9140(95)01721-6. PMID   18966469.
7. Casimero, Charnete; Bigham, Teri; McGlynn, Ruairi J.; Dooley, James S. G.; Ternan, Nigel G.; Snelling, William J.; Critchley, Megan E.; Zinkel, Cameron L.; Smith, Robert B.; Sabogal-Paz, Lyda P.; Davis, James (2019-12-01). "Electroanalytical properties of chlorophenol red at disposable carbon electrodes: Implications for Escherichia coli detection" (PDF). Bioelectrochemistry. 130: 107321. doi:10.1016/j.bioelechem.2019.06.006. PMID   31306878. S2CID   196813601.

Cited sources

• Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. ISBN   9781498754293.