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The Ternary Stannides MgRuSn 4 and Mg x Rh 3 Sn 7—x (x = 0.98—1.55)
Author(s) -
Schlüter Martin,
Kunst Andreas,
Pöttgen Rainer
Publication year - 2002
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 - 10.1002/1521-3749(200212)628:12<2641::aid-zaac2641>3.0.co;2-y
Subject(s) - tin , crystallography , ternary operation , crystal structure , diffractometer , materials science , magnesium , rhodium , ruthenium , metal , lattice constant , x ray crystallography , transition metal , diffraction , chemistry , metallurgy , catalysis , physics , biochemistry , computer science , optics , programming language
The magnesium transition metal stannides MgRuSn 4 and Mg x Rh 3 Sn 7—x (x = 0.98—1.55) were synthesized from the elements in glassy carbon crucibles in a water‐cooled sample chamber of a high‐frequency furnace. They were characterized by X‐ray diffraction on powders and single crystals. MgRuSn 4 adopts an ordered PdGa 5 type structure: I 4/ mcm , a = 674.7(1), c = 1118.1(2) pm, wR2 = 0.0506, 515 F 2 values and 12 variable parameters. The ruthenium atoms have a square‐antiprismatic tin coordination with Ru—Sn distances of 284 pm. These [RuSn 8/2 ] antiprisms are condensed via common faces forming two‐dimensional networks. The magnesium atoms fill square‐prismatic cavities between adjacent [RuSn 4 ] layers with Mg—Sn distances of 299 pm. The rhodium based stannides Mg x Rh 3 Sn 7—x crystallize with the cubic Ir 3 Ge 7 type structure, space groupe Im 3 m . The structures of four single crystals with x = 0.98, 1.17, 1.36, and 1.55 have been refined from X‐ray diffractometer data. With increasing tin substitution the a lattice parameter decreases from 932.3(1) pm for x = 0.98 to 929.49(6) pm for x = 1.55. The rhodium atoms have a square antiprismatic tin/magnesium coordination. Mixed Sn/Mg occupancies have been observed for both tin sites but to a larger extend for the 12 d Sn2 site. Chemical bonding in MgRuSn 4 and Mg x Rh 3 Sn 7—x is briefly discussed.