Neodymium compounds are compounds formed by the lanthanide metal neodymium (Nd). In these compounds, neodymium generally exhibits the +3 oxidation state, such as NdCl3, Nd2(SO4)3 and Nd(CH3COO)3. Compounds with neodymium in the +2 oxidation state are also known, such as NdCl2 and NdI2. Some neodymium compounds have colors that vary based upon the type of lighting. [1]
Neodymium can form four trihalides of the form NdX3. It reacts vigorously with all the stable halogens: [2]
The dihalides NdCl2 and NdBr2 are dark green solids, [3] with the same crystal structure as PbCl2 [3] and NdI2 is a dark purple solid. They can be obtained in the Nd-NdX3 eutectic system. [4]
NdF4 is known only under matrix isolation conditions. [5] The related M3[NdF7] (M = K, Rb, Cs) are very unstable towards moisture or heat. [6] They can be prepared by high-pressure fluorination or from noble gas fluorides. [7]
Neodymium(III) sulfate can be directly obtained by dissolving neodymium(III) oxide in sulfuric acid. [8] It is soluble in water, and its anhydrous form has a solubility of 8 g at 20˚C. Neodymium(III) nitrate can be obtained by dissolving neodymium(III) oxide in nitric acid. [9] Evaporating the resulting solution yields hydrated neodymium(III) nitrate, where the hexahydrate form is the most common. Heating the hexahydrate further will obtain the anhydrous form. Reacting neodymium(III) chloride with sodium arsenate in solution would obtain neodymium(III) arsenate, [10] which is a faint pink powder that is insoluble in water. It has good thermal stability, and its pKsp,c is 21.86±0.11. [11] Neodymium(III) oxalate is a rose-coloured crystal which decomposes from its decahydrate to its anhydrous form when heated, and when heated further, decomposes to Nd2O2C2O4, [12] and then finally obtaining neodymium(III) oxide. [13] Neodymium(III) carbonate is the carbonate of neodymium where neodymium exhibits the +3 oxidation state. It can be obtained by reacting neodymium(III) chloride with ammonium bicarbonate in water or from the hydrolysis of neodymium(III) chloroacetate: [14]
Neodymium(III) acetate is a purple solid [15] that is soluble in water. [16] [17] The solubility of the compound increases when sodium acetate is added, forming a blue complex. [18] It can be obtained by the reaction of neodymium(III) chloride and sodium acetate: [19]
Organoneodymium compounds are compounds that have a neodymium–carbon bond. These compounds are similar to those of the other lanthanides, characterized by an inability to undergo π backbonding. They are thus mostly restricted to the mostly ionic cyclopentadienides (isostructural with those of lanthanum) and the σ-bonded simple alkyls and aryls, some of which may be polymeric. [20]
Neodymium(III) chloride does not have strong luminescence, [21] though it serves as a source of Nd3+ ions for various light emitting materials. The latter include Nd-YAG lasers and Nd-doped optical fiber amplifiers, which amplify light emitted by other lasers. The Nd-YAG laser emits infrared light at 1.064 micrometres and is the most popular solid-state laser (i.e. laser based on a solid medium).
Neodymium glass (Nd:glass) is produced by the inclusion of neodymium(III) oxide (Nd2O3) in the glass melt. Usually in daylight or incandescent light neodymium glass appears lavender, but it appears pale blue under fluorescent lighting. Neodymium may be used to color glass in delicate shades ranging from pure violet through wine-red and warm gray. [22]
Neodymium(III) acetate can be used as a substitute for uranyl acetate, [23] which is used in electron microscopy. [24]
Neodymium is a chemical element with the symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly producing pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states. It is generally regarded as having one of the most complex spectra of the elements. Neodymium was discovered in 1885 by the Austrian chemist Carl Auer von Welsbach, who also discovered praseodymium. It is present in significant quantities in the minerals monazite and bastnäsite. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Neodymium is fairly common—about as common as cobalt, nickel, or copper and is widely distributed in the Earth's crust. Most of the world's commercial neodymium is mined in China, as is the case with many other rare-earth metals.
Cerium(III) chloride (CeCl3), also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic salt; it rapidly absorbs water on exposure to moist air to form a hydrate, which appears to be of variable composition, though the heptahydrate CeCl3·7H2O is known. It is highly soluble in water, and (when anhydrous) it is soluble in ethanol and acetone.
Praseodymium(III) chloride is the inorganic compound with the formula PrCl3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate.
Neodymium(III) chloride or neodymium trichloride is a chemical compound of neodymium and chlorine with the formula NdCl3. This anhydrous compound is a mauve-colored solid that rapidly absorbs water on exposure to air to form a purple-colored hexahydrate, NdCl3·6H2O. Neodymium(III) chloride is produced from minerals monazite and bastnäsite using a complex multistage extraction process. The chloride has several important applications as an intermediate chemical for production of neodymium metal and neodymium-based lasers and optical fibers. Other applications include a catalyst in organic synthesis and in decomposition of waste water contamination, corrosion protection of aluminium and its alloys, and fluorescent labeling of organic molecules (DNA).
Europium(III) chloride is an inorganic compound with the formula EuCl3. The anhydrous compound is a yellow solid. Being hygroscopic it rapidly absorbs water to form a white crystalline hexahydrate, EuCl3·6H2O, which is colourless. The compound is used in research.
Neodymium(III) fluoride is an inorganic chemical compound of neodymium and fluorine with the formula NdF3. It is a purplish pink colored solid with a high melting point.
Lanthanide trichlorides are a family of inorganic compound with the formula LnCl3, where Ln stands for a lanthanide metal. The trichlorides are standard reagents in applied and academic chemistry of the lanthanides. They exist as anhydrous solids and as hydrates.
Neodymium acetate is an inorganic salt composed of a neodymium atom trication and three acetate groups as anions where neodymium exhibits the +3 oxidation state. It has a chemical formula of Nd(CH3COO)3 although it can be informally referred to as NdAc because Ac is an informal symbol for acetate. It commonly occurs as a light purple powder.
Praseodymium compounds are compounds formed by the lanthanide metal praseodymium (Pr). In these compounds, praseodymium generally exhibits the +3 oxidation state, such as PrCl3, Pr(NO3)3 and Pr(CH3COO)3. However, compounds with praseodymium in the +2 and +4 oxidation states, and unlike other lanthanides, the +5 oxidation state, are also known.
Neodymium(III) nitride is a chemical compound of neodymium and nitrogen with the formula NdN in which neodymium exhibits the +3 oxidation state and nitrogen exhibits the -3 oxidation state. It is ferromagnetic, like gadolinium(III) nitride, terbium(III) nitride and dysprosium(III) nitride. Neodymium(III) nitride is not usually stoichiometric, and it is very hard to create pure stoichiometric neodymium nitride.
Neodymium(III) carbonate is an inorganic compound, a salt, where neodymium is in the +3 oxidation state and the carbonate ion is in the -2 oxidation state. It has a chemical formula of Nd2(CO3)3. The anhydrous form is purple-red, while the octahydrate is a pink solid. Both of these salts are insoluble in water.
Neodymium arsenate, also known as neodymium(III) arsenate, is the arsenate of neodymium with the chemical formula of NdAsO4. In this compound, neodymium exhibits the +3 oxidation state. It has good thermal stability, and its pKsp,c is 21.86±0.11.
Europium(III) acetate is an inorganic salt of europium and acetic acid with the chemical formula of Eu(CH3COO)3. In this compound, europium exhibits the +3 oxidation state. It can exist in the anhydrous form, sesquihydrate and tetrahydrate. Its hydrate molecule is a dimer.
Neodymium(III) oxalate is the oxalate salt of neodymium, with the chemical formula of Nd2(C2O4)3 in the anhydrous or hydrate form. Its decahydrate decomposes to the anhydrous form when heated, and when heated further, decomposes to Nd2O2C2O4, finally obtaining neodymium(III) oxide. It dissolves in hydrochloric acid to form Nd(C2O4)Cl·3H2O.
Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod.
Terbium compounds are compounds formed by the lanthanide metal terbium (Tb). Terbium generally exhibits the +3 oxidation state in these compounds, such as in TbCl3, Tb(NO3)3 and Tb(CH3COO)3. Compounds with terbium in the +4 oxidation state are also known, such as TbO2 and BaTbF6. Terbium can also form compounds in the 0, +1 and +2 oxidation states.
Cerium acetate is an inorganic compound with the chemical formula of Ce(CH3COO)3. It is a white powder that is soluble in water. Its 1.5 hydrate loses water at 133°C to obtain an amorphous anhydrous form, and the amorphous phase changes to crystal at 212°C, and phase changes again at 286°C.
Erbium compounds are compounds containing the element erbium (Er). These compounds are usually dominated by erbium in the +3 oxidation state, although the +2, +1 and 0 oxidation states have also been reported.
Lutetium compounds are compounds formed by the lanthanide metal lutetium (Lu). In these compounds, lutetium generally exhibits the +3 oxidation state, such as LuCl3, Lu2O3 and Lu2(SO4)3. Aqueous solutions of most lutetium salts are colorless and form white crystalline solids upon drying, with the common exception of the iodide. The soluble salts, such as nitrate, sulfate and acetate form hydrates upon crystallization. The oxide, hydroxide, fluoride, carbonate, phosphate and oxalate are insoluble in water.
Lanthanide chlorides are a group of chemical compounds that can form between a lanthanide element and chlorine. The lanthanides in these compounds are usually in the +2 and +3 oxidation states, although compounds with lanthanides in lower oxidation states exist.