The transition from 4f to 5d elements from the structural point of view

Abstract

How structural properties reflect the transition from lanthanides to transition metals.

Chemdex: quantification and distributions of valence numbers, oxidation numbers, coordination numbers, electron numbers, and covalent bond classes for the elements

“…This propensity for La–O binding corresponds to results from a related study involving oxygen affinity of lanthanoids that concludes Lu is closer in properties to the adjacent d-block elements rather than La. 49 On the other hand a different study based upon sets of Sc, Y, La, and Lu compounds concludes there is no chemical basis for placing Lu beneath Sc and Y. There are few characterised compounds of Lr and Ac, but by convention these remain placed below Lu and La respectively.…”

“…The membership of IUPAC group 3 elements (Sc, Y, La, Ac or Sc, Y, Lu, Lr) is the subject of discussion 48–50 and an IUPAC group is concerned with a recommendation. 51 Both lutetium and lanthanum are predominantly trivalent and the average coordination number of lutetium (7.3) based upon Chemdex data matches that of yttrium (7.5) quite closely (Fig.…”

“…The actinoids are grouped below the lanthanoids in most modern periodic tables but the earlier actinoids are placed below the earlier d-block elements in some early tables. 9,45,49 For instance, Remy's table shows the actinoids Th-U placed below the d-block elements Hf-W so it is appropriate to consider the placing of the early actinoids based upon the Chemdex data. 49 Structural data for the later actinoids are sparse, understandable because of scarcity of samples and difficulties of handling.…”

“…9,45,49 For instance, Remy's table shows the actinoids Th-U placed below the d-block elements Hf-W so it is appropriate to consider the placing of the early actinoids based upon the Chemdex data. 49 Structural data for the later actinoids are sparse, understandable because of scarcity of samples and difficulties of handling.…”

The location and composition of Group 3 of the periodic table

“…Unfortunately this argument introduces an anomaly in the overall regularity of term symbols. Alvarez (2020) supports lutetium on the basis of trends in atomic size, coordination number, and relative abundance of metal-oxygen bonds. However, the trends involved apply regardless of whether lutetium is under Y or at the end of the f-block, after Yb.…”