New bond-valence parameters for lanthanides

Abstract

The bond-valence method, especially the valence-sum rule, is very useful for checking if the structures formed by trivalent lanthanides are correct. In this work bond-valence parameters (Rij), which connect bond valences and bond lengths, have been computed for a large number of bonds taken from the Cambridge Structural Database, Version 5.24 (2002) [Allen (2002). Acta Cryst. B58, 380-388]. The calculated values of bond-valence parameters for metal-organic compounds decrease with an increase in lanthanide atomic number; the Rij values are also smaller than bond-valence parameters calculated for inorganic compounds. A summary of bond-valence sums calculated for Rij given in this work and reported in the literature, and a functional correlation between lanthanide-oxygen distances and coordination number are presented.

Nitrogen‐Rich Compounds of the Lanthanoids: Highlights and Summary

“…In this modification, the contribution of the LnÀO bonds to the total valence of Ln is subtracted from the formal valence of V(Ln) ¼ 3. This is done based on the literature values of R(LnÀO) [48] for the respective trivalent Ln ion and with the respective coordination number (CN) (Eqn. 2).…”

Data mining of iron(II) and iron(III) bond-valence parameters, and their relevance for macromolecular crystallography

“…Some notable results based on CSD data include bond-valence parameters for copper (Shields et al , 2000), lanthanides (Trzesowska et al , 2004, 2006), cadmium (Palenik, 2006), antimony (Palenik et al , 2005) and ammonium (García-Rodríguez et al , 2000). Several more metals were discussed later, as summarized and reviewed by Brown (2009).…”

Magnesium sulphate complexes with hexamethylenetetramine and 1,10-phenanthroline

“…The sulphate(VI) anion in both compounds can be considered as fully delocalised (Table 2), however, in both cases one S-O bond is slightly but clearly shorter and one longer than two others S-O bonds. The bond valences were computed as , 29], where R ij is the bond-valence parameter (in the formal sense R ij can be considered as a parameter equal to the idealised single-bond length between i and j atoms for given b [30,31]) and b was taken as 0.37 Å [32,33]. The R Mg-O and R Mg-N were taken as 1.693 and 1.85, respectively [33].…”