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Lanthanide and actinide aqua ions have higher solvation numbers (often 8 to 9), with the highest known being 11 for Ac 3+. The strength of the bonds between the metal ion and water molecules in the primary solvation shell increases with the electrical charge, z, on the metal ion and decreases as its ionic radius, r, increases. Aqua ions are ...
All of the lanthanides form Ln 2 Q 3 (Q= S, Se, Te). [8] The sesquisulfides can be produced by reaction of the elements or (with the exception of Eu 2 S 3) sulfidizing the oxide (Ln 2 O 3) with H 2 S. [8] The sesquisulfides, Ln 2 S 3 generally lose sulfur when heated and can form a range of compositions between Ln 2 S 3 and Ln 3 S 4.
The lighter/larger lanthanides adopt a hexagonal 7-coordinate structure while the heavier/smaller ones adopt a cubic 6-coordinate "C-M 2 O 3" structure. [50] All of the sesquioxides are basic, and absorb water and carbon dioxide from air to form carbonates, hydroxides and hydroxycarbonates. [ 57 ]
For example, thorium perchlorate is very water-soluble and crystallises from acidic solutions as the tetrahydrate Th(ClO 4) 4 •4H 2 O, while thorium nitrate forms tetra- and pentahydrates, is soluble in water and alcohols, and is an important intermediate in the purification of thorium and its compounds. [25]
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.
Actinide salts can also be obtained by dissolving the corresponding hydroxides in acids. Nitrates, chlorides, sulfates and perchlorates of actinides are water-soluble. When crystallizing from aqueous solutions, these salts form hydrates, such as Th(NO 3) 4 ·6H 2 O, Th(SO 4) 2 ·9H 2 O and Pu 2 (SO 4) 3 ·7H 2 O. Salts of high-valence actinides ...
2.3 Lanthanides and actinides. 2.3.1 Lanthanides. 2.3.2 Actinides. 2.4 56 elements in sequence. 2.5 Groups. ... It is accomplished by loss of one or more electrons ...
The lanthanide contraction only partially accounts for this anomaly. [11] Because the 6s 2 orbital is contracted by relativistic effects and may therefore only weakly contribute to any chemical bonding, Hg–Hg bonding must be mostly the result of van der Waals forces. [11] [13] [14] Mercury gas is mostly monatomic, Hg(g).