Trzesowska Agata, Kruszynski Rafal, Bartczak Tadeusz J
Department of X-ray Crystallography and Crystal Chemistry, Institute of General and Ecological Chemistry, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz, Poland.
Acta Crystallogr B. 2006 Oct;62(Pt 5):745-53. doi: 10.1107/S0108768106016429. Epub 2006 Sep 18.
Ln-O and Ln-N bond-valence parameters have been computed in coordination complexes for lanthanides (Ln) at oxidation states other than +3 (Ce(IV), Sm(II), Eu(II) and Yb(II)). Moreover, Ln-Cl, Ln-S and Ln-C(pi-bonded) bond-valence parameters are presented, as calculated for coordination compounds. In general, the bond-valence parameters decrease in the order Ln-O > Ln-C > Ln-N > Ln-Cl > Ln-S. It has been found that the values of bond-valence parameters decrease with increasing lanthanide atomic number for coordination compounds. As expected, the values of lanthanide-oxygen and lanthanide-nitrogen bond-valence parameters diminish with increasing lanthanide oxidation state. Several examples are given where the total valence of the lanthanide ion is apparently incorrectly assigned, as well as cases where bond-valence method calculations confirm the doubtful oxidation state assignment.
已计算出氧化态不为 +3 的镧系元素（Ln，即 Ce(IV)、Sm(II)、Eu(II) 和 Yb(II)）在配位络合物中的 Ln - O 和 Ln - N 键价参数。此外，还给出了针对配位化合物计算得出的 Ln - Cl、Ln - S 和 Ln - C（π键合）键价参数。一般来说，键价参数按 Ln - O > Ln - C > Ln - N > Ln - Cl > Ln - S 的顺序递减。已发现，对于配位化合物，键价参数的值随镧系元素原子序数的增加而减小。正如预期的那样，镧系元素 - 氧和镧系元素 - 氮键价参数的值随镧系元素氧化态的增加而减小。文中给出了几个例子，其中镧系离子的总价态显然被错误指定，以及键价法计算证实可疑氧化态指定的情况。
