ISSN:
0044-2313
Keywords:
Oxides of monovalent Co and Ni
;
structure
;
MAPLE
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
On the Existence of Polynary Oxides of the Alkali Metals with Monovalent Cobalt and NickelFor the first time we obtained RbNa2NiO2, KNa2NiO2, Na3CoO2 and K3CoO2 [RbNa2NiO2: Na2NiO2 + Rb2O, Rb:Ni = 1.8:1, 600°C, 28 d, Ni-tube; KNa2NiO2: Na2NiO2 + K2O, K:Ni = 1.8:1, 600°C, 20 d, Ni-tube; Na3CoO2: Na2O + CoO: Na:Co = 8.8:1, 500°C, 20 d, Co-tube; K3CoO2: K2O + CoO: K:Co = 4.4:1, 550°C, 20 d, Co-tube]. According to X-ray structure analysis of single crystals monovalent Co and Ni is present [always four-circle-diffractometer data, MoKα-radiation; RbNa2NiO2: AED 2, all 163 Io(hkl), R = 3.4%, Rw = 1.9%, I4/mmm, a = 461.7(1), c = 973.6(3) pm, Z = 2; KNa2NiO2: AED 2, all 341 Io(hkl), R = 5.6%, Rw = 3.5%, Cmma, a = 1 048.5(3), b = 626.8(1), c = 621.9(1) pm, Z = 4; Na3CoO2: PW 1 100, 517 of 568 Io(hkl), R = 2.9%, Rw = 1.8%, P42/mnm, a = 940.0, c = 464.5 pm, Z = 4; K3CoO2: PW 1 100, all 940 Io(hkl), R = 5.0%, Rw = 3.9%, Pnma, a = 1 190.0, b = 730.4, c = 604.1 pm, Z = 4]. All samples are red, the single crystals transparent. Two O2- coordinate Ni1+ and Co1+, respectively, like a dumb-bell. Mean Fictive Ionic Radii, MEFIR, and Effective Coordination Numbers, ECoN, and Madelung part of lattice energy, MAPLE, are given.
Notes:
Erstmals wurden RbNa2NiO2, KNa2NiO2, Na3CoO2 und K3CoO2 dargestellt [RbNa2NiO2: Na2NiO2 + Rb2O, Rb:Ni = 1,8:1, 600°C, 20 d, Nickelbombe; KNa2NiO2: Na2NiO2 + K2O, K:Ni = 1,8:1, 600°C, 20 d, Nickelbombe; Na3CoO2: Na2O + CoO, Na:Co = 8,8:1, 500°C, 20 d, Cobaltbombe; K3CoO2: K2O + CoO, K:Co = 4,4:1, 550°C, 20 d, Cobaltbombe]. Nach Einkristalldaten weisen Cobalt wie Nickel die Oxydationsstufe + 1 auf [jeweils Vierkreisdiffraktometer mit MoKα-Strahlung; RbNa2NiO2: AED 2, alle 163 Io(hkl), R = 3,4%, Rw = 1,9%, I4/mmm, a = 461,7(1), c = 973,6(3) pm, Z = 2; KNa2NiO2: AED 2, alle 341 Io(hkl), R = 5,6%, Rw = 3,5%, Cmma, a = 1 048,5(3), b = 626,8(1), c = 621,9(1) pm, Z = 4; Na3CoO2: PW 1 100, 517 aus 568 Io(hkl), R = 2,9%, Rw = 1,8%, P42/mnm, a = 940,0, c = 464,5 pm, Z = 4; K3CoO2: PW 1 100, alle 940 Io(hkl), R = 5,0%, Rw = 3,9%, Pnma, a = 1 190,0, b = 730,4, c = 604,1 pm, Z = 4].Alle Präparate sind rot, die Einkristalle transparent. Ni1+ bzw. Co1+ ist jeweils in Form einer Hantel von 2 O2- koordiniert. Mittlere Fiktive Ionenradien (MEFIR) und Effektive Koordinationszahlen (ECoN), sowie der Madelunganteil der Gitterenergie (MAPLE), werden angegeben.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19936190520
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