| | NIOBIUM(V) CHLORIDE Basic information |
| | NIOBIUM(V) CHLORIDE Chemical Properties |
| Melting point | 204.7 °C(lit.) | | Boiling point | 254 °C(lit.) | | density | 2.75 g/mL at 25 °C(lit.) | | vapor pressure | 22.8hPa at 153.8℃ | | Fp | 248.2°C | | storage temp. | no restrictions. | | solubility | Soluble in alcohol, hydrochloric acid, carbon tetrachloride and chloroform. | | form | powder | | color | Yellow | | Specific Gravity | 2.75 | | Water Solubility | Soluble in water, alcohol, HCl, and Carbon tetrachloride. | | Sensitive | Moisture Sensitive | | Merck | 14,6557 | | CAS DataBase Reference | 10026-12-7(CAS DataBase Reference) | | EPA Substance Registry System | Niobium chloride (NbCl5) (10026-12-7) |
| Hazard Codes | C,Xi | | Risk Statements | 20/21/22-34 | | Safety Statements | 26-27-28-36/37/39 | | RIDADR | UN 3260 8/PG 2 | | WGK Germany | 3 | | RTECS | QU0350000 | | F | 21 | | TSCA | Yes | | HazardClass | 8 | | PackingGroup | III | | HS Code | 28273985 | | Toxicity | LD50 in mice (mg/kg): 61 i.p., 940 orally (Haley); LD50 in mice, rats (mg/kg): 829, 1400 orally (Zhilova, Kasparov) |
| | NIOBIUM(V) CHLORIDE Usage And Synthesis |
| Chemical Properties | yellow fine crystalline powder | | Physical properties | Yellow monoclinic crystals; deliquesces; density 2.75 g/cm3; decomposes in moist air with the evolution of HCl; melts at 204.7°C; vaporizes at 254°C; decomposes in water; soluble in alcohol, hydrochloric acid, chloroform and carbon tetrachloride. | | Uses | Used to form mixed chloro-aryloxide compounds, such as [Nb(OC6H3-2,6-i-Pr2)2Cl3]2, which form pyridine or phosphine adducts with a distorted six-coordinate geometry.† | | Uses | Lewis acid catalyst in organic synthesis. | | Uses | Niobium(V) chloride is the precursor in the preparation of pure niobium, and ferroniobium. It is used as a Lewis acid catalyst in organic synthesis in activating alkenes in the carbonyl-ene reaction and the Diels-Alder reaction. | | Preparation | Niobium pentachloride is obtained as an intermediate during extraction of niobium from its ores (see Niobium). Also, the pentachloride is obtained readily by direct chlorination of niobium metal at 300 to 350°C: 2Nb + 5Cl2 → 2NbCl5
The pentachloride also may be made by chlorination of niobium pentoxide in the presence of carbon at 300°C. The products, however, contain small amounts of niobium oxide trichloride, NbOCl3. | | Hazard | May evolve fumes of hydrogen chloride.
Keep dry | | Flammability and Explosibility | Nonflammable | | Safety Profile | Poison by
intraperitoneal route. Moderately toxic by
ingestion. May cause kidney injury. When
heated to decomposition it emits very toxic
fumes of Cl-. See also NIOBIUM and
CHLORIDES. | | Purification Methods | It forms yellow, very deliquescent crystals which decompose in moist air to liberate HCl. It should be kept in a dry box flushed with N2 in the presence of P2O5. Wash it with CCl4 and dry it over P2O5. The yellow crystals usually contain a few small, dirty white pellets among the yellow needles. These should be easily picked out. Upon grinding in a dry box, however, they turn yellow. NbCl5 has been sublimed and fractionated in an electric furnace. [Epperson Inorg Synth VII 163 1963, Alexander & Fairbrother J Chem Soc suppl 233 1949.] d2 5 20 pK25 |
| | NIOBIUM(V) CHLORIDE Preparation Products And Raw materials |
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