520-10-5

Basic information

• Product Name: ARSENAZO I
• Synonyms: ARSENAZO;ARSENAZO 1;ARSENAZO I;2-(O-ARSONOPHENYLAZO)-1,8-DIHYDROXYNAPHTHALENEDISULFONIC ACID, SODIUM SALT;2-(1,8-DIHYDROXY-3,6-DISULFO-2-NAPHTHYLAZO)BENZENEARSONIC ACID TRISODIUM SALT;2-(1,8-DIHYDROXY-3,6-DISULFO-2-NAPHTHYLAZO)PHENYLARSONIC ACID DISODIUM SALT;2-(2-ARSONOPHENYLAZO)CHROMOTROPIC ACID DISODIUM SALT;O-(1,8-DIHYDROXY-3,6-DISULFO-2-NAPHTHYLAZO)BENZENEARSONIC ACID SODIUM SALT
• CAS NO: 520-10-5
• Molecular Formula: C₁₆H₁₃AsN₂O₁₁S₂
• Molecular Weight: 614.28
• EINECS: 222-600-3
• Mol File: 520-10-5.mol
• Article Data: 0

Chemical Properties

• Melting Point: ≥300 °C(lit.)
• Boiling Point: °Cat760mmHg
• Flash Point: °C
• Appearance: /
• Density: g/cm³
• Solubility: methanol: 1 mg/mL, clear, red
• PKA: -0.71±0.40(Predicted)
• CAS DataBase Reference: ARSENAZO I(CAS DataBase Reference)
• NIST Chemistry Reference: ARSENAZO I(520-10-5)
• EPA Substance Registry System: ARSENAZO I(520-10-5)

Safety Data

• Hazard Codes: T,N
• Statements: 23/25-50/53
• Safety Statements: 20/21-28-45-60-61
• RIDADR: UN 3465 6.1/PG 3
• WGK Germany: 3
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 520-10-5(Hazardous Substances Data)

Usage

Description

ARSENAZO I is a chemical reagent that reacts with various metal ions to form colored complexes. It is used for the photometric determination of metal ions and as an indicator in complexometric determination of some metals.

Uses

Used in Analytical Chemistry:
ARSENAZO I is used as a reagent for the photometric determination of metal ions such as uranium(IV), thorium(IV), zirconium(IV), scandium(III), lanthanum(III), cerium(III), aluminium(III), beryllium(III), titanium(III), niobium(III), tantalum(III), vanadium(IV), tin(IV), bismuth(III), gallium(III), copper(III), palladium(II), magnesium(II), and calcium(II). The complex formation reaction can be made selective for individual metal ions by adjusting the pH of the solution.
Used in Complexometric Determination:
ARSENAZO I is used as an indicator in the complexometric determination of metals such as plutonium and thorium. Its analytical sensitivity is comparatively high (0.05-0.1 γ/ml), but its importance is decreasing in analytical practice due to the increasing significance of the related reagent, Arsenazo III, which provides more stable complexes with higher absorbances and greater analytical sensitivity.

InChI:InChI=1/C16H13AsN2O11S2/c20-12-7-9(31(25,26)27)5-8-6-13(32(28,29)30)15(16(21)14(8)12)19-18-11-4-2-1-3-10(11)17(22,23)24/h1-7,20-21H,(H2,22,23,24)(H,25,26,27)(H,28,29,30)/b19-18+

Synthetic route

copper(II) choride dihydrate + 3-(2-arsono-phenylazo)-4,5-dihydroxy-naphthalene-2,7-disulfonic acid (520-10-5) → [Cu2(O3AsC6H4NNC10H3(OH)2(SO3)2)]

Conditions	Yield
With hydrogenchloride; sodium hydroxide; potassium chloride In water at 25.degdee.C, ionic strength of 1.0 mol*dm**-3 (KCl), pH values in range 3.221-11.045; not isolated, monitored by UV at 340-700 nm;