Structure and Chemical Bonding of ScNiB 4

• Published in: Zeitschrift für anorganische und allgemeine Chemie (1950) Vol. 639; no. 11; pp. 2071 - 2076
• Main Authors: Eickerling, Georg, Scherer, Wolfgang, Fickenscher, Thomas, Rodewald, Ute Ch, Pöttgen, Rainer
• Format: Journal Article
• Language: English
• Published: 01-09-2013
• ISSN: 0044-2313; 1521-3749
• DOI: 10.1002/zaac.201200522

The ternary polyboride ScNiB
4
was synthesized from the elements by arc‐melting and subsequent annealing for crystal growth. The structure of ScNiB
4
was investigated by X‐ray diffraction on powder and a single crystal (high‐resolution data up to 2θ = 140°, Mo‐
K
α
radiation): YCrB
4
type,
Pbam
,
a
= 578.7(2),
b
= 1120.7(3),
c
= 327.2(1) pm,
R
1 = 0.0477 (1286
F
2
values with
I
≥ 2(
I
)),
wR
2 = 0.1137 (all 2225
F
2
values), and 38 variables. The four crystallographically independent boron sites build up planar layers which consist of almost regular pentagons and heptagons which sandwich the nickel and scandium atoms, respectively. Within the two‐dimensional [B
4
] networks each boron atom has slightly distorted trigonal planar boron coordination with B–B distances in the range 171–181 pm. A topological analysis of the electron density reveals the differences between the bonding situation of the scandium atoms in the heptagonal prismatic environment on the one hand and the Ni atoms in the pentagonal prismatic environment on the other hand.