Premium
On the Crystal Chemistry of Oxoniccolates of the Alkali‐, Alkaline Earth and Rare Earth Metals
Author(s) -
MüllerBuschbaum Hanskarl
Publication year - 2011
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.201000443
Subject(s) - non blocking i/o , octahedron , crystallography , alkali metal , nickel , alkaline earth metal , crystal structure , materials science , chemistry , inorganic chemistry , metallurgy , organic chemistry , biochemistry , catalysis
This review describes features of the crystal chemistry of oxoniccolates containing large cations like alkali‐, alkaline earth and rare earth metals. Starting with alkali‐oxoniccolates it is shown that Ni + exhibits the unusual coordination number CN = 2 (dumbbells) in K 2 / Rb 2 / Na 2 NiO 2 and K 3 NiO 2 . K 2 NiO 2 is the only known oxoniccolat showing O–Ni–O‐dumbbells with nickel in the oxidation state Ni 2+ . The trigonal planar coordination (found within silver‐oxocompounds) is restricted to Ba 3 NiO 4 and K 9 Ni 2 O 7 . Square planar polygons (NiO 4 ) are found in Nd 4 Ni 3 O 8 ; Na 2 NiO 2 ; Ki 2 NiO 2 ; BaNiO 2 and SrNiO 2 for example. A special quality in the crystal chemistry of connected square planar NiO 4 ‐polygons is the formation of Ni 6 O 12 ‐rings in Ba 2 NaNi 3 O 6 . There are two compounds showing Ni 3+ O 4 ‐tetrahedra: K 9 Ni 2 O 7 and Na 5 NiO 4 . All the other oxoniccolates exhibit octahedral or trigonal prismatic coordination of nickel by oxygen. Always of interest are the so called one dimensional oxides, showing chains of two times face‐shared octahedra and/or trigonal prisms, found in Sr 3 Yb 0.89 NiO 6 , Sr 3 PbNiO 6 ; Sr 12 Ni 7.5 O 27 ; Sr 4 Ni 3 O 9 ; BaNi 0.83 O 2.5 and NaSr 12 Ni 7 O 23 . Large chains of the type –[(octahedron) 2 –(prism)–(octahedron) 2 –prism–(octahedron) 3 –(prism)–(octahedron) 2 –(prism)–(octahedron) 2 ]– filled by Ni 3+ and Ni 4+ are found in Sr 9 Ni 6.64 O 21 . Many of the oxidation states of nickel are published with non integral valence states like Ni 2.667+ , Ni 2.5+ , Ni 2.292+ , Ni 3.614 . Using calculations of the Coulomb‐terms of lattice energy most of the mixed valences could be split up in integral numbers protecting the electro neutrality between metal ions and oxygen.