Xylenol orange
Names
Preferred IUPAC name
2,2′,2′′,2′′′-{(1,1-Dioxo-2,1λ6-benzoxathiole-3,3(1H)-diyl)bis[(6-hydroxy-5-methyl-3,1-phenylene)methylenenitrilo]}tetraacetic acid
Other names
XO[1]
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.015.049 Edit this at Wikidata
EC Number
  • 216-553-8
UNII
  • InChI=1S/C31H32N2O13S/c1-17-7-21(9-19(29(17)42)11-32(13-25(34)35)14-26(36)37)31(23-5-3-4-6-24(23)47(44,45)46-31)22-8-18(2)30(43)20(10-22)12-33(15-27(38)39)16-28(40)41/h3-10,42-43H,11-16H2,1-2H3,(H,34,35)(H,36,37)(H,38,39)(H,40,41) checkY
    Key: ORZHVTYKPFFVMG-UHFFFAOYSA-N checkY
  • O=C(O)CN(CC(=O)O)Cc1c(O)c(cc(c1)C3(OS(=O)(=O)c2ccccc23)c4cc(c(O)c(c4)CN(CC(=O)O)CC(=O)O)C)C
Properties
C31H32N2O13S
Molar mass 672.66 g·mol−1
Melting point 195 °C (383 °F; 468 K)
200 mg/mL
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazards (white): no code
2
1
2
Flash point > 93 °C (199 °F; 366 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Xylenol orange is an organic reagent, most commonly used as a tetrasodium salt as an indicator for metal titrations. When used for metal titrations, it will appear red in the titrand and become yellow once it reaches its endpoint. Historically, commercial preparations of it have been notoriously impure,[2] sometimes consisting of as little as 20% xylenol orange, and containing large amounts of semi-xylenol orange and iminodiacetic acid. Purities as high as 90% are now available.

It is fluorescent, and has excitation maximums of 440 & 570 nm and an emission maximum of 610 nm.[3]

References

  1. ^ Li, Zhong-Guang (2019-01-01), Khan, M. Iqbal R.; Reddy, Palakolanu Sudhakar; Ferrante, Antonio; Khan, Nafees A. (eds.), "Chapter 5 - Measurement of Signaling Molecules Calcium Ion, Reactive Sulfur Species, Reactive Carbonyl Species, Reactive Nitrogen Species, and Reactive Oxygen Species in Plants", Plant Signaling Molecules, Woodhead Publishing, pp. 83–103, ISBN 978-0-12-816451-8, archived from the original on 2023-11-11, retrieved 2023-11-11
  2. ^ Gay, Craig; Collins, James; Gebicki, Janusz M. (1999), "Determination of Iron in Solutions with the Ferric–Xylenol Orange Complex", Analytical Biochemistry, 273 (2): 143–148, doi:10.1006/abio.1999.4207, PMID 10469483
  3. ^ "Fluorescence - Fluorochrome Data Tables". Molecular Expressions Microscopy Primer: Specialized Microscopy Techniques. 2018-09-11. Retrieved 2020-01-30.


source: http://en.wikipedia.org/wiki/Xylenol_Orange