Valencies of the lanthanides

Abstract

The valencies of the lanthanides vary more than was once thought. In addition to valencies associated with a half-full shell, there are valencies associated with a quarter- and three-quarter-full shell. This can be explained on the basis of Slater’s theory of many-electron atoms. The same theory explains the variation in complexing constants in the trivalent state (the “tetrad effect”). Valency in metallic and organometallic compounds is also discussed.

Solid‐state synthesis of multicomponent equiatomic rare‐earth oxides

“…The diffusion of the cations into a single crystal lattice may be facilitated by starting with binary oxides with similar crystal structures and taking advantage of phase transitions that occur with increasing temperature. Another factor that may play an important role is the multivalence of some of the rare‐earth elements . The cations can be oxidized or reduced during synthesis resulting in a preferential structure different from the structure of the initial binary oxide.…”

“…Another factor that may play an important role is the multivalence of some of the rare-earth elements. 42 The cations can be oxidized or reduced during synthesis resulting in a preferential structure different from the structure of the initial binary oxide.…”

Geochemistry of rare earth elements and cerium anomaly in sedimentary marine carbonates: modern concepts

“…Однако Ce и Eu способны менять валентность (Ce -на IV, Eu -на II), реагируя на изменения редокс-параметров среды. Строго говоря, менять валентность на IV могут также Pr, Nd, Tb и Dy, а на II -Nd, Sm, Dy, Tm и Yb, но, по-видимому, не в экзогенных процессах (Гурвич и др., 1980;Харитонова, Вах, 2015;Johnson, Nelson, 2017). Особое поведение Ce и Eu при определённых физико-химических условиях приводит к возникновению соответствующих аномалий (см.…”

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“…Однако Ce и Eu способны менять валентность (Ce -на IV, Eu -на II), реагируя на изменения редокс-параметров среды. Строго говоря, менять валентность на IV могут также Pr, Nd, Tb и Dy, а на II -Nd, Sm, Dy, Tm и Yb, но, по-видимому, не в экзогенных процессах (Гурвич и др., 1980;Харитонова, Вах, 2015;Johnson, Nelson, 2017). Особое поведение Ce и Eu при определённых физико-химических условиях приводит к возникновению соответствующих аномалий (см.…”