NIOBIUM(V) IODIDE Property

Melting point:

>300 °C(lit.)

Density 

5.32

solubility 

reacts with H2O

form 

yellow-black monoclinic crystals

color 

yellow-black monoclinic crystals, crystalline

EPA Substance Registry System

Niobium iodide (NbI5) (13779-92-5)

Safety

Hazard Codes 

C

Risk Statements 

34

Safety Statements 

22-26-27-36/37/39-45

RIDADR 

UN 3260 8/PG 2

WGK Germany 

3

HazardClass 

8

PackingGroup 

III

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P240Ground/bond container and receiving equipment.

P241Use explosion-proof electrical/ventilating/lighting/…/equipment.

P242Use only non-sparking tools.

P243Take precautionary measures against static discharge.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P370+P378In case of fire: Use … for extinction.

P403+P235Store in a well-ventilated place. Keep cool.

P501Dispose of contents/container to..…

NIOBIUM(V) IODIDE Chemical Properties,Usage,Production

Chemical Properties

black powder(s); monoclinic, a=1.058 nm, b=0.658nm, c=1.388nm; sensitive to moisture; obtained by reaction of excess I2 with Nb metal in a sealed tube [STR93] [KIR81]

Preparation

A vertical tube of Vycor or Pyrex glass (I.D. approximately 23 mm., wall thickness 2.5 mm.) is charged with 4-12 g. of Nb metal (either solid or powder). A dense glass wool plug is placed over the charge and approximately 20 cm. from the closed tube end, followed by a 20% excess of pure, resublimed I₂ powder. The tube and its contents are thoroughly degassed in a high vacuum and melt-sealed under vacuum. Then the reactor is placed in a slightly inclined position (with the Nb metal at the higher and the I₃ at the lower end) and heated by means of two separate tubular electric furnaces (these meet at the center of the tube). The niobium is heated to 300℃ and the I₂ first to 180℃ and then to 250℃. The reaction is nearly quantitative after 10-15 hours and Nbl₅ crystals collect in the transition zone between the two temperature regions. The yields are lower with Nb powder than with solid Nb. The reactor is broken at the center, the Nbl₅ is removed under anhydrous conditions, and repeatedly rinsed with dry petroleum ether (under N₂) until the adhering I₂ is removed and the petroleum ether stays colorless. The traces of petroleum ether are evaporated in vacuum.