Chemistry:Niobium pentaiodide

From HandWiki
Niobium pentaiodide
Nb2I10.svg
Names
Other names
Niobium(V) iodide
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 237-422-1
UNII
Properties
Nb2I10
Molar mass 1475
Appearance yellow solid
Density 5.30 g/cm3
Melting point 543 °C (1,009 °F; 816 K) sublimes
Hazards
GHS pictograms GHS05: Corrosive
GHS Signal word Danger
H314
P260, P264, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P363, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Niobium pentaiodide is the inorganic compound with the formula Nb2I10. Its name comes from the compound's empirical formula, NbI5.[1] It is a diamagnetic, yellow solid that hydrolyses readily. The compound adopts an edge-shared bioctahedral structure, which means that two NbI5 units are joined by a pair of iodide bridges. There is no bond between the Nb centres.[2] Niobium(V) chloride, niobium(V) bromide, tantalum(V) chloride, tantalum(V) bromide, and tantalum(V) iodide, all share this structural motif.

Preparation

Niobium pentaiodide forms from the reaction of niobium with iodine:

2 Nb + 5 I2 → 2 NbI5

The method used for the preparation of tantalum(V) iodide using aluminium triiodide fails to produce pure pentaiodide.[3]

Properties

Niobium(V) iodide forms of dark, brassy, extremely moisture-sensitive needles or flakes. Its crystallises in the monoclinic crystal system with space group P21/c (space group no. 14), a = 1058 pm, b = 658 pm, c = 1388 pm, β = 109.14°. The crystal structure consists of zigzag chains of corner-sharing NbI6 octahedra. Since so far only twinned crystals of this phase have been obtained, and the structure determination is uncertain.[4] If the reaction of the elements is carried out with an excess of iodine, a triclinic modification is created with the space group P1 (No. 2), a = 759.1 pm, b = 1032.2 pm, c = 697.7 pm, α = 90 .93°, β = 116.17°, γ = 109.07°, which consists of isolated molecules Nb2I10.[3][5] This structure is isotypic with that of triclinic niobium(V) bromide.

References

  1. Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford: Butterworth-Heinemann. ISBN:0-7506-3365-4.
  2. Krebs, Bernt; Sinram, Diethard "Darstellung, Struktur und Eigenschaften einer neuen Modifikation von NbI5 (Preparation, structure and properties of a new modification of NbI5" Zeitschrift fǔr Naturforschung, Teil B: Anorganische Chemie, Organische Chemie 1980, volume 35b, pp. 12-16.
  3. 3.0 3.1 G. Braurer (1963). "Niobium(V) Iodide". in G. Brauer. Handbook of Preparative Inorganic Chemistry, 2nd Ed.. 1. NY, NY: Academic Press. pp. 1315. 
  4. Littke, W.; Brauer, G. (Oct 1963). "Darstellung und Kristallstruktur von Niobpentajodid" (in en). Zeitschrift für anorganische und allgemeine Chemie 325 (3-4): 122–129. doi:10.1002/zaac.19633250304. ISSN 0044-2313. https://onlinelibrary.wiley.com/doi/10.1002/zaac.19633250304. 
  5. B. Krebs, D. Sinram: Darstellung, Struktur und Eigenschaften einer neuen Modifikation von NbI5. In: Zeitschrift fuer Naturforschung, Teil B. Anorganische Chemie, Organische Chemie, 1980, 35, S. 12–16.
HI He
LiI BeI2 BI3 CI4 NI3 I2O4,
I2O5,
I4O9
IF,
IF3,
IF5,
IF7
Ne
NaI MgI2 AlI3 SiI4 PI3,
P2I4
S ICl,
ICl3
Ar
KI CaI2 Sc TiI4 VI3 CrI3 MnI2 FeI2 CoI2 NiI2 CuI ZnI2 Ga2I6 GeI2,
GeI4
AsI3 Se IBr Kr
RbI SrI2 YI3 ZrI4 NbI5 Mo Tc Ru Rh Pd AgI CdI2 InI3 SnI4,
SnI2
SbI3 TeI4 I Xe
CsI BaI2   HfI4 TaI5 W Re Os Ir Pt AuI Hg2I2,
HgI2
TlI PbI2 BiI3 Po AtI Rn
Fr RaI2   Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
La Ce Pr Nd Pm SmI2 Eu Gd TbI3 Dy Ho Er Tm Yb Lu
Ac ThI4 Pa UI3,
UI4
Np Pu Am Cm Bk Cf EsI3 Fm Md No Lr