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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.
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]
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]
Lanthanide chlorides are a group of chemical compounds that can form between a lanthanide element (from lanthanum to lutetium) 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.
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]
Lanthanide trichlorides are a family of inorganic compound with the formula LnCl 3, 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.
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]