Electronic Stabilization Effects:  Three New K−In−T (T = Mg, Au, Zn) Network Compounds

Abstract

The ternary compounds K(34)In(91.05(9))Mg(13.95(9)) (I), K(34)In(96.19(6))Au(8.81(6)) (II), and K(34)In(89.95(1))Zn(13.05(7)) (III) have been synthesized by high-temperature means and structurally characterized by single-crystal X-ray diffraction methods. All are analogues of earlier products in which Li is substituted for some In in a hypothetical K(34)In(105) lattice. They consist of complex three-dimensional anionic networks built of In(12) icosahedra and M(28) triply fused icosahedra (M = In or In/T and T = Mg, Au, or Zn). The K atoms bridge between cluster faces or edges and form K(136) clathrate-IotaIota type networks. Two neighboring M(28) units are interconnected by an M atom to form a sandwich complex (M(28))M(M(28)) in I and II or by a Zn-Zn dimer in (M(28))ZnZn(M(28)) in III. Mixed In/T sites only occur in the M(28) portions. Phase stabilization through electronic tuning is present in all three via substitution of the electron-poorer T elements for In. Extended Hückel analyses indicate that all metal-metal bonding within the M(28) cluster appears to be optimized in I and III even though both are metallic. The size of the substituted element is also important in the structural features, as is especially shown by the Zn compound.

Synthesis, structure and properties of SrAu3In3 and EuAu3In3—New indides with gold zig-zag chains

“…The Sr-In and Eu-In distances are much longer (Table 3). Both the ranges of the Au-In distances and the coordination of the cations in SrAu 3 In 3 and EuAu 3 In 3 are similar to the many alkali metalgold-indides [26][27][28][29] and references therein.…”

More of the “Fullercages”

“…also: hR (414–27)–Ga 73.6 Na 20.2 K 6.2 ,54,55, hR (417–15)–Ga 61.1 Na 15.7 Cd 12.8 K 10.4 ,56 hR 417–Ga 66.9 Na 24.5 Cu 8.7 ,57 hR 417–Ga 66.2 Na 24.5 Cu 5.0 Cd 4.3 ,58 hR 417–Ga 58.4 Na 24.5 Zn 17.2 ,59 hR 417–In 65.5 K 24.5 Mg 10.0 ,53 hR (420–9)–In 65.7 K 24.8 Zn 9.5 ,53,60, hR (417–2)–Zn 48.1 Sn 27.3 Na 24.6 15…”

Networks of icosahedra in the sodium–zinc–stannides Na16Zn13.54Sn13.46(5), Na22Zn20Sn19(1), and Na34Zn66Sn38(1)

“…Phase III is isostructural to Na 102 Cu 36 Ga 279 [12] and is a new representative of triicosahedral phases [13]. The unit cell (Fig.…”

“…In similar phases containing such clusters, a transition metal atom-Cu or Cd-is located at the inversion center. Related triply fused icosahedra in gallides, such as in Na 13 K 4 Ga 49.57 [26], also frequently exhibit atomic defects preferably at the corresponding sites of the triangle made of the three defective Zn13 atoms and comparable complexes with a bridging atom have been found in the phases Na 102 Cu 36 Ga 279 [12], K 34 Li 12.70 In 92.30 [14], or the K-In-T (T ¼ Mg, Au, Zn) phases [13]. Two other kinds of interaction between neighboring triply fused icosahedra dependent on the occupancy of the participating triangles have been reported: In K 34 In 89.95(1) Zn 13.05 (7) [13] a bridging Zn-Zn dimer (occ.…”

“…Triply fused icosahedra occur as building units in b-boron and also as {(Ga/M) 28 } in Na 102 (MGa) 315 (M ¼ Cu, Zn) [12], as {(In/T) 28 } (T ¼ Mg, Zn, Au) in K 34 (In/T) 105 [13], and as {(In/Li) 28 } in K 34 In 92. 30 Li 12.70 [14].…”