Synthesis and structure of orthorhombic cadmium platinum oxide, CdPt3O6

Abstract

Abstract. Mr=793.7 , orthorhombic, Cmmm, a= 7.2144(6), b=10.190(1), c=3.1650(2)A, V= 232.67 (6) A 3, Z = 2, D x = 11.33 gcm -3, 2(Ag Ka) = 0.5609 A, # = 513.5 cm -1, T= 293 K, F(000) = 660, R = 0.047 for 417 unrejected reflections in the range 0.0849 < sin 0/2 < 0-8914 A -1. Crystals of CdPt306 were grown by a hydrothermal technique. Bulk electrical-resistivity measurements on a pellet of compressed powder yielded values of p(298 K)= 0.03 f~m and E a = 0.04 e V (1 e V = 1.60 x 10-19j) in the range 5 to 298 K. This low resistivity is related to metal-metal distances of 3.165 A in a structure which includes chains of edge-shared PtO6 octahedra and columnar stacks of planar PtO 4 groups extending along [0011.

LaSrCo0.5Rh0.5O3.25 and LaSrNi0.5Rh0.5O3.25:Topochemically Reduced, Mixed Valence Rh(I)/Rh(III) Oxides

“…9 11,13 Similar behavior is also observed for the 5d member of group 11, platinum, with octahedral Pt IV O 6 and square-planar Pt II O 4 units observed in a wide range of M 2+ Pt II Pt IV 2 O 6 (M = Cd, Mn, Co, Zn, Ni, Mg) oxides. 10,12 However, to date analogous charge-separated Ir I /Ir III oxides have not been prepared. Reported topochemically reduced iridium oxides, such as Sr 2 FeIrO 4 , or Sr 2 Co 0.5 Ir 0.5 O 3 , are observed to contain d 7 Ir 2+ cations in square-planar coordination sites.…”

“…Analogous coordination-site driven disproportionations are observed for 4d and 5d transition metal cations with d 7 electron counts, such as Pd 3+ and Pt 3+ . In this case, the favorability of square-planar coordinated d 8 cations, combined with octahedrally coordinated low-spin d 6 cations, destabilizes the d 7 electron count, as seen in KPd 2 O 3 (K 2 Pd II 3 Pd IV O 6 ), CdPt 3 O 6 (CdPt II Pt IV 2 O 6 ), and a number of other Pt and Pd oxides. − …”

High‐Pressure Synthesis and Characterization of New Actinide Borates, AnB4O8 (An=Th, U)

“…MAPLE values (madelung part of lattice energy)31–33 were calculated for comparison with the MAPLE values as obtained from the summation of the binary actinide oxides, ThO 2 34 and UO 2 ,35 and with that of the high‐pressure modification B 2 O 3 ‐II 36. Values of 55 317 and 55 569 kJ mol −1 were obtained for ThB 4 O 8 and UB 4 O 8 , respectively, in comparison with 55 421 kJ mol −1 (deviation=0.2 %) and 55 721 kJ mol −1 deviation=0.3 %) for the corresponding binary oxides (ThO 2 (11 544 kJ mol −1 )+2 B 2 O 3 ‐II (2×21 938 kJ mol −1 ); UO 2 (11 544 kJ mol −1 )+2×B 2 O 3 ‐II (2×21 938 kJ mol −1 )).…”

Synthesis, Characterization, and X-Ray Powder Structure of K2ZrGe2O7

“…The bond angles deviate only slightly from 903. The Ge}O bond distances (1.737(7)}1.776(3) A s ) are also regular (13,14), and both average Zr}O and Ge}O bond lengths are equal (within experimental error) to the sum of their ionic radii for their respective coordination numbers (Zr}O, 2.12 A s ; Ge}O 1.78 A s ) (25).…”