Neodymium(III) iodide is an inorganic salt of iodine and neodymium with the formula NdI3.Ezhov, Y.S., Komarov, S.A. & Sevast’yanov, V.G. Refinement of molecular constants of neodymium triiodide by electron diffraction. J Struct Chem 41, 593–596 (2000). https://doi.org/10.1007/BF02683920 Neodymium uses the +3 oxidation state in the compound. The anhydrous compound is a green powdery solid at room temperature.
Preparation Heating neodymium and iodine in an inert atmosphere produces this salt: 2 Nd + 3 I2 → 2 NdI3 It can also be prepared by the reaction of neodymium(III) oxide and hydroiodic acid to make a hydrate: Nd2O3 + 6 HI → 2 NdI3 + 3 H2O The anhydrate can then be obtained by heating the nonahydrate with ammonium iodide: NdI3 • 9 H2O + nNH4I → NdI3 + nNH3 + nHI + 9H2O
Physical properties
Neodymium(III) iodide forms green, water-soluble hygroscopic crystals. It has a melting point of 784°C. It forms a nonahydrate crystal NdI3.9H2O – belongs to the orthorhombic crystal system, space group Pmmn, lattice constants a = 1.16604 nm, b = 0.80103 nm, c = 0.89702 nm, Z = 4.
Other compounds NdI3 also forms some compounds with N2H4, such as NdI3·3N2H4·2H2O which is a dark green crystal, soluble in methanol and ethanol and insoluble in water, benzene and toluene, d20°C = 3.42 g/cm³.Uchenye zapiski: Serii︠a︡ khimicheskikh nauk (S.M. Kirov adyna Azărbai̐jan Dȯvlăt Universiteti; 1975), page 78. Retrieved January 13, 2021. (Translated from Vietnamese)
NdI3 also forms some compounds with urea, such as NdI3 5CO(NH2)2 which is a lavender color crystal.Russian Journal of Inorganic Chemistry, Episode 18, Part 2 (British Library Lending Division with the cooperation of the Royal Society of Chemistry, 1973), page 1655. Retrieved 13 January 2021.
NdI3 also forms some compounds with thiourea, such as NdI3·2CS(NH2)2·9H2O which is a pale pink crystal.Alikberova L.Yu., Albov D.V., Antonenko T.A., Kochetova I.M., Rukk N.S. — Thiourea complexes of neodymium(III) and gadolinium(III) iodides. synthesis and structure. Fine Chemical Technologies. 2010, 5 (3): 30–33. (in Russian).
See also Neodymium(II) iodide Neodymium Iodine Lanthanide
References