Sodium Iodide Usage And Synthesis

                                                        Sodium Iodide Usage And Synthesis

Uses

1.Used as iodometric reagent

2.Sodium iodide is widely used for halide exchange (Finkelstein reaction), for example in the conversion of an alkyl chloride, allyl chloride and arylmethyl chloride into their respective iodides, which are precursors for pharmaceutical and fine chemical products. They are used to ehnance the efficiency of the formation of Wittig adducts from less reactive chlorides and bromides. Appropriate prepartions find use as a nutrient supplement. Sodium iodide is used as the precursor to the control agent in ab initio emulsion polymerization. Sodium iodide finds use in the determination of dissolved oxygen in the modified Winkler method, synthesis of the fluorescent dye coppersensor-1 (CS1) for imaging labile copper pools in biological samples, and the cleavage of esters, lactones, carbamates and ethers in combination with chlorotrimethylsilane.

3.Sodium iodide was used as a component in the preparation of Mayer′s hematoxylin stain solution.
It may be used in the following processes:

• Precursor in the polymerization of butyl acrylate.

• Chaotropic agent in the extraction of DNA.

• Deprotecting agent in the removal of N-tert-butyloxycarbonyl group in amino acids.

• Water-soluble fluorescence quenching reagent.

Production method

Eight iron iodide method: based on the mass ratio of iodine method: iron = 3.3: 1, first add the washed iron powder to the reactor; then add water with the mass ratio of the added water amount over iron being 7: 1. Successively add iodine tablet. Owing to the large amount of heating generated during the reaction between iodine and iron, we should use chilled water to cool outside of the reactor to a temperature below 65 ℃. After addition of iodine tablet, the solution turns dark red-brown. When the solution exhibits light green, add the second batch of iodine; after further removal of the iron powder by filtration, add iodine for reaction to generate eight iron iodide. Sodium bicarbonate solution was added to the vessel, add slowly with stirring of eight iron iodide for reaction and there will be carbon dioxide gas released at this time. The reaction solution was allowed to stand; the supernatant was aspirated and concentrated by evaporation to 70~72 ° Bé, filter upon hot, cool and crystallize, centrifuge, separate, and dry to obtain the finished product of sodium iodide.
Fe + I2 → FeI2
3FeI2 + I2 → Fe3I8
Fe3I8 + 8NaHCO3 → 8NaI + Fe3O4 + 4H2O + 8CO2 ↑
Reduction method of iron powder: take 100% to 103% the theoretical amount of caustic soda, add water into 10% solution and heat in the reactor to 60~80 ℃. Add quantitatively of iodine with several times, maintain the temperature of 80~90 ℃ and react upon stirring for about 1h with the reaction liquid being brown and the Ph range of 6 to 7 while there is white crystals of sodium iodide being precipitated out. The reaction solution was cooled to below 30 ℃. Add 2 times the theoretical amount of iron powder to reduce the sodium iodate to sodium iodide. At the beginning, the reaction is relative fierce. When the reaction is eased, heat to boiling and continue the stirring for reaction of 1~2h, then use 10% caustic soda solution for adjustment the Ph to 8; boil for 30min, after cooling, standing for filtration; evaporate and concentrate the colorless filtrate so that the crystal is precipitated out; further filter upon hot, dry to obtain the finished product of sodium iodide.
3I2 + 6NaOH → 5NaI + NaIO3 + 3H2O
NaIO3 + 3Fe + 3H2O → NaI + 3Fe (OH) 2