Salicylaldoxime

Salicylaldoxime Property

Melting point:

57-59 °C 59-61 °C (lit.)

Boiling point:

251.96°C (rough estimate)

Density 

1.2528 (rough estimate)

refractive index 

1.5030 (estimate)

storage temp. 

Sealed in dry,Room Temperature

solubility 

sparingly soluble in water, soluble in ethanol, diethyl ether, acetone, benzene.

pka

pK1:1.37(＋1);pK2:9.18;pK3:12.11 (25°C)

form 

Powder

color 

Bordeaux to purple-red

Odor

Odorless

Water Solubility 

Slightly soluble in water

Merck 

14,8327

BRN 

1859881

InChIKey

ORIHZIZPTZTNCU-VMPITWQZSA-N

CAS DataBase Reference

94-67-7(CAS DataBase Reference)

NIST Chemistry Reference

Benzaldehyde, 2-hydroxy-, oxime(94-67-7)

EPA Substance Registry System

Benzaldehyde, 2-hydroxy-, oxime (94-67-7)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

22-36/37/38

Safety Statements 

26-36

WGK Germany 

3

RTECS 

VN5775000

TSCA 

Yes

HazardClass 

IRRITANT

HS Code 

29280000

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

Salicylaldoxime Chemical Properties,Usage,Production

Uses

Salicylaldoxime is an organic compound described by the formula C6H4CH=NOH-2-OH and it is the oxime of salicylaldehyde. This crystalline, colorless solid is a chelator and sometimes used in the analysis of samples containing transition metal ions, with which it often forms brightly colored coordination complexes.

Elements Extraction

Salicylaldoxime is recognized as a selective precipitant for copper, although it forms water-insoluble chelates with a number of elements. Ingvar Dahl invested the extraction of divalent magnesium, manganese, cobalt, nickel, copper, zinc, cadmium, mercury, and lead with solutions of salicylaldoxime in benzene and the effect of the reagent concentration and particularly the pH of the aqueous phase on the extractability was also studied. The solubility of salicylaldoxime in organic solvents has been utilized in the solvent extraction of carious elements.

Chemical Properties

off-white to light beige crystalline powder

Uses

Salicylaldoxime reacts with several metal ions to give intensively coloured complexes which are insoluble in water. The structure of the copper(II), nickel(II) and palladium(II) complexes is shown in Fig. 14 (structure I), and that of the manganese(II), iron(II), cobalt(II) and zinc(II) complexes in Fig. 14 (structure II). The copper(Il) and palladium(II) salicylaldoxime complexes are of importance from an analytical point of view. The complexes precipitated from aqueous media are easily filterable and washable and are weighed after drying at 100°C. The precipitates are of stoichiometric composition.
The outstanding stabilities of the copper(II) and palladium(II) complexes make the reagent suitable for the selective determination of these metal ions. These two complexes form quantitatively at low pH values where the complexes of other metal ions do not exist.
Besides the gravimetric method, salicylaldoxime is also useful in the volumetric, amperometric and nephelometric determinations of copper and palladium.
Salicylaldoxime gives a black precipitate with VOs~ in media containing sulfuric acid; this is soluble in chloroform to give an orange solution. The reaction is specific for vanadium which can thus be detected by this method in the presence of almost all other metals.
In neutral medium salicylaldoxime reacts with iron(III) to give a red complex which is soluble in water. The reaction is utilized for the detection of micro amounts of iron.

Uses

As a reagent for copper and nickel.

Synthesis

The general procedure for the synthesis of salicylaldehyde oxime from salicylaldehyde is as follows: 30 mmol of 2-hydroxybenzaldehyde, 60 mmol of sodium bicarbonate, and 45 mmol of hydroxylamine hydrochloride were dissolved in a mixed ethanol/water solvent (50 mL of ethanol/5 mL of water) at room temperature. The reaction mixture was stirred for 2 hours, followed by removal of most of the solvent by concentration. The residue was diluted with ethyl acetate and filtered directly. The filtrate was concentrated to give a final 3.99 g (98% yield) of the colorless oily product salicylaldoxime.

References

[1] Journal fuer Praktische Chemie (Leipzig), 1989, vol. 331, # 5, p. 870 - 872
[2] Journal of the Iranian Chemical Society, 2010, vol. 7, # 1, p. 114 - 118
[3] Patent: CN103864754, 2016, B. Location in patent: Paragraph 0378; 0379
[4] Chemical Communications, 2014, vol. 50, # 56, p. 7531 - 7534
[5] Revue Roumaine de Chimie, 2015, vol. 60, # 9, p. 875 - 880