| Identifiers | |
|---|---|
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.033.608 |
| EC Number |
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| |
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| Properties | |
| Cl3Nb | |
| Molar mass | 199.26 g·mol−1 |
| Appearance | black solid |
| Density | 3.75 |
| Structure[1] | |
| hexagonal | |
| P3m1 | |
a = 6.744,c = 12.268 | |
Formula units (Z) | 2 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Niobium(III) chloride also known asniobium trichloride is a compound ofniobium andchlorine. The binary phase NbCl3 is not well characterized but manyadducts are known.
(hexyne).png)
Nb3Cl8 is produced by reduction ofniobium(V) chloride withhydrogen, or just by heating.
Salt-free reduction of dimethoxyethane solution of NbCl5 with 1,4-disilyl-cyclohexadiene in the presence of3-hexyne produces thecoordination complex NbCl3(dimethoxyethane)(3-hexyne):
An impuredimethoxyethane (dme) adduct of niobium trichloride was produced by reduction of a dme solution of niobium pentachloride withtributyltin hydride:[3]
Nb3Cl8 has ahexagonal close packed array of chloride ions. Triangles of niobium occur in octahedral spaces in the chloride array. The compositions with higher chloride have some niobium atoms missing from the structure, creating vacancies and giving rise tononstoichiometric compounds. NbCl4 has this pattern of vacancies stretched until the niobium atoms are in pairs rather than triangles. So NbCl3 can be considered as a solid solution of Nb3Cl8 and Nb2Cl8.[4]
The colour of niobium trichloride varies depending on the niobium:chloride ratio. NbCl2.67 is green, while NbCl3.13 is brown.[1]
3.svg)
When heated to over 600 °C niobium trichloride disproportionates to niobium metal and niobium pentachloride.
NbCl3(dimethoxyethane) has received significant attention as a reagent for reductive coupling of carbonyls and imines.[6] It is sold as a1,2-dimethoxyethane complex. Nb(III) adducts are also known for1,4-dioxane anddiethyl ether.
Niobium(III) chloride forms a series of compounds with the formula Nb2Cl6Lx with Nb=Nbdouble bond. Withtertiary phosphines and arsines, the complexes are edge-share bioctahedra, e.g., Nb2Cl6(PPhMe2)4.[7] Thioethers form adducts with one bridging thioether (R2S). These face-sharing bioctahedra have the formula Nb2X6(R2S)3 (X = Cl, Br).