Lanthanide chemistry Atomic structures

Krebs, Robert E. The history and use of our earth s chemical elements a reference guide. Westport (CT) Greenwood P, 1998. ix, 346p. ISBN 0-313-30123-9 A short history of chemistry — Atomic structure The periodic table of the chemical elements — Alkali metals and alkali earth metals - Transition elements metals to nonmetals — Metallics and metalloids - Metalloids and nonmetals — Halogens and noble gases - Lanthanide series (rare-earth elements) — Actinide, transuranic, and transactinide series... 

The actinides, Th and U, are included here because their chemistry is often analogous to that of group IVA however, parallels to lanthanide chemistry are certainly present, too. There are relatively few well-characterized complexes of Th(III). (jj -Cp)3Th shows reactivity similar to that of ( -Cp)3Zr e.g., the Th(III) complex abstracts a halogen atom from I2 and CHCI3 to give ( -Cp)3ThX (X = I and Cl). The structurally characterized [fj -(Me3Si)2Cp]3Th shows similar reaction with t-BuCl " . ... 

The second series of inner transition elements, the actinides, have atomic numbers ranging from 90 (thorium, Th) to 103 (lawrencium, Lr). All of the actinides are radioactive, and none beyond uranium (92) occur in nature. Like the transition elements, the chemistry of the lanthanides and actinides is unpredictable because of their complex atomic structures. What could be happening at the subatomic level to explain the properties of the inner transition elements In Chapter 7, you ll study an expanded theory of the atom to answer this question. 

The Toulouse quantum-chemistry group created quasirelativistic pseudopotentials based on the atomic structure method developed by Barthelat et al. (1980) and the general procedure of adjustment devised by Durand and Barthelat (1974, 1975). The pseudopotential is constructed in such a way that the pseudo-orbitals coincide best with the all-electron valence orbitals and are smooth in the core region, i.e. an approach which has later been termed norm-conserving (Hamaim et al. 1979) or shape-consistent (Christiansen et al. 1979, Rappe et al. 1981). No parameter sets for the lanthanides and actinides have been published up to now. 

Figure6.32 Structure of the cationic cluster complex [Eu4(p.3-0H)4(nic)6(H20)8]2 + (nic= nicoti-nate). Hydrogen atoms are removed for clarity [57]. (Redrawn from X. Kong et al., Hydrolytic synthesis and structural characterization of lanthanide hydroxide clusters supported by nicotinic acid, Inorganic Chemistry, 48, 3268-3273, 2009.)...

Aside from the zinc complex, the coordination chemistry of the porphocyanines remains largely unexplored. Nonetheless, the pseudohexagonal arrangement of the six potentially donating nitrogen atoms present in porphocyanine has led to speculation that such systems could serve as ligands for larger cations such as those of the lanthanide or actinide series (as illustrated by the hypothetical structure... 

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