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The lanthanite crystal structure consists of layers of 10-fold coordinated REE-oxygen (O) polyhedra and carbonate (CO 3 2−) groups connected by hydrogen bonds to interlayer water molecules, forming a highly hydrated structure.
Organolanthanide chemistry is the field of chemistry that studies organolanthanides, compounds with a lanthanide-carbon bond. Organolanthanide compounds are different from their organotransition metal analogues in the following ways: They are far more air- and water-sensitive and are often pyrophoric.
Lanthanide metals react exothermically with hydrogen to form LnH 2, dihydrides. [1] With the exception of Eu and Yb, which resemble the Ba and Ca hydrides (non-conducting, transparent salt-like compounds),they form black pyrophoric, conducting compounds [6] where the metal sub-lattice is face centred cubic and the H atoms occupy tetrahedral sites. [1]
The lanthanides become harder as the series is traversed: as expected, lanthanum is a soft metal. Lanthanum has a relatively high resistivity of 615 nΩm at room temperature; in comparison, the value for the good conductor aluminium is only 26.50 nΩm. [28] [29] Lanthanum is the least volatile of the lanthanides. [30]
Praseodymium(IV) oxide can be produced by boiling Pr 6 O 11 in water or acetic acid: [16] Pr 6 O 11 + 3 H 2 O → 4 PrO 2 + 2 Pr(OH) 3. Praseodymium(III,IV) oxide is the most stable form of the praseodymium oxides at ambient temperature and pressure. [17] It is soluble in water [18] and has a cubic fluorite structure. [19]
LaC 2 reacts with water to form acetylene, C 2 H 2 and a mixture of complex hydrocarbons. [3] LaC 2 is a metallic conductor, in contrast to CaC 2 which is an insulator. [3] The crystal structure of LaC 2 shows that it contains C 2 units with a C-C bond length of 130.3 pm, which is longer than the C-C bond length in calcium carbide, 119.2 pm, which is close to that of ethyne. [3]
Lanthanum oxide is a white solid that is insoluble in water, but dissolves in acidic solutions. La 2 O 3 absorbs moisture from air, converting to lanthanum hydroxide. [2] Lanthanum oxide has p-type semiconducting properties and a band gap of approximately 5.8 eV. [3]
In contrast, lanthanide triflates' complexes with the product are easily separated by water, and the lanthanide triflate hydrate thus formed can be simply heated to boil the water away (This does not work for aluminium chloride due to loss of HCl; same goes for the lanthanide chlorides, hence the necessity of the triflate counterion).