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Sc 4 Pt 7 Si 2 – An Intergrowth Structure of ScPtSi and ScPt Related Slabs
Author(s) -
Harmening Thomas,
van Wüllen Leo,
Eckert Hellmut,
Rodewald Ute Ch.,
Pöttgen Rainer
Publication year - 2010
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201000003
Subject(s) - crystallography , scandium , diffractometer , crystal structure , chemistry , silicon , platinum , trigonal prismatic molecular geometry , group (periodic table) , materials science , inorganic chemistry , catalysis , octahedron , organic chemistry , biochemistry
The metal‐rich silicide Sc 4 Pt 7 Si 2 was synthesized by arc‐melting. Sc 4 Pt 7 Si 2 crystallizes with its own structure type, space group Pbam . The structure was refined from single‐crystal X‐ray diffractometer data: a = 647.6(1), b = 1617.1(3), c = 398.96(9) pm, wR 2 = 0.0495, 807 F 2 values and 42 variables. Sc 4 Pt 7 Si 2 is an intergrowth structure of slightly distorted ScPtSi (TiNiSi type) and ScPt (CsCl type) related slabs. The silicon atoms have the typical coordination number 9 (4 Sc + 5 Pt) in the form of a tricapped trigonal prism. Together, the platinum and silicon atoms build up a complex three‐dimensional [Pt 7 Si 2 ] network with short Pt–Si (238–246 pm) and Pt–Pt (282–303 pm) distances. The scandium atoms fill distorted square prismatic or pentagonal prismatic voids within this network, also with short Sc–Pt distances (276–308 pm). The structural difference of these two scandium species is reflected by substantial discrepancies in 45 Sc chemical shifts. The quadrupolar interaction parameters that were estimated from the nutation behavior of the two signals were used for an assignment to the two sites.