Thymolphthalexone

Thymolphthalexone

Names
Other names Thymolphthalexon, thymolphthalein complexone, [1] TPC [2]
Identifiers
CAS Number	1913-93-5
3D model (JSmol)	Interactive image
ChemSpider	101208
ECHA InfoCard	100.016.026
EC Number	217-627-2
PubChem CID	112918
CompTox Dashboard (EPA)	DTXSID10172646
InChI InChI=1S/C38H44N2O12/c1-19(2)24-11-29(21(5)26(35(24)49)13-39(15-31(41)42)16-32(43)44)38(28-10-8-7-9-23(28)37(51)52-38)30-12-25(20(3)4)36(50)27(22(30)6)14-40(17-33(45)46)18-34(47)48/h7-12,19-20,49-50H,13-18H2,1-6H3,(H,41,42)(H,43,44)(H,45,46)(H,47,48) Key: AGXCADFSYJNMEG-UHFFFAOYSA-N
SMILES CC1=C(C=C(C(=C1CN(CC(=O)O)CC(=O)O)O)C(C)C)C2(C3=CC=CC=C3C(=O)O2)C4=C(C(=C(C(=C4)C(C)C)O)CN(CC(=O)O)CC(=O)O)C
Properties
Chemical formula	C38H44N2O12
Molar mass	720.772 g·mol−1
Appearance	white crystalline powder
Melting point	191 °C (376 °F; 464 K)
Solubility in water	soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Thymolphthalexone is a chemical compound from the group of iminodiacetic acid derivatives of thymolphthalein. ^[3] Its chemical formula is C₃₈H₄₄N₂O₁₂.

This is a metallochromic indicator widely used in complexometric titrations, particularly for the determination of transition metals. The compound features a thymolphthalein-derived core linked to aminopolycarboxylic acid functional groups. This hybrid architecture grants the compound the ability to preferentially bind specific metal ions through coordinated interactions.

Synthesis

Thymolphthalexone can be obtained by Mannich condensation of formaldehyde and iminodiacetic acid with thymolphthalein. ^[4]

Physical properties

Thymolphthalexone forms a white crystalline powder soluble in water and organic solvents. ^[2]

Uses

Thymolphthalexone and its sodium salt are used as an indicator or photometric reagent for alkaline metal ions, such as those of calcium, strontium, barium, and others. ^{[5] [6]}

See also

• Bromothymol blue
• Litmus
• Methyl orange
• Phenolphthalein
• pH indicator
• Universal indicator

References

1. Burgot, Jean-Louis (30 March 2012). Ionic Equilibria in Analytical Chemistry. Springer Science & Business Media. p. 528. ISBN   978-1-4419-8382-4 . Retrieved 17 April 2025.
2. Cheng, Kuang Lu; Ueno, Keihei; Imamura, Toshiaki (29 September 2017). CRC Handbook of Organic Analytical Reagents. Routledge. p. 267. ISBN   978-1-351-45722-4 . Retrieved 17 April 2025.
3. "Thermo Scientific Chemicals Thymolphthalexone | Fisher Scientific". Fisher Scientific . Retrieved 17 April 2025.
4. Cheng, KuangLu; Imamura, Toshiaki; Cheng, Kuang Lu (1992). CRC Handbook of Organic Analytical Reagents, Second Edition (2nd ed.). Bosa Roca: CRC Press. p. 9. ISBN   978-1-351-45721-7 . Retrieved 17 April 2025.
5. "Thymolphthalexon | CAS 62698-55-9 | SCBT - Santa Cruz Biotechnology". scbt.com . Retrieved 17 April 2025.
6. Babaei, Ali; Babazadeh, Mitra; Shams, Esmaeil (2007). "Simultaneous Determination of Iron, Copper, and Cadmium by Adsorptive Stripping Voltammetry in the Presence of Thymolphthalexone" . Electroanalysis. 19 (9): 978–985. doi:10.1002/elan.200603812. ISSN   1521-4109 . Retrieved 17 April 2025.