Über Oxocuprate. XVII. Zur Kenntnis von Ca2CuO2Cl2 und Ca2CuO2Br2

About Oxocuprates. XVII. Ca₂CuO₂Cl₂ and Ca₂CuO₂Br₂ The so far unkown compounds Ca₂CuO₂Cl₂ (I) and Ca₂CuO₂Br₂ (II) were prepared and examined by X-ray single crystal methods. They are isotypic with Sr₂CuO₂Cl₂ ((I) a = 386.6, c = 1 497.5; (II) a = 387.5, c = 1 726.4 pm, space group d–I4/mmm). A discussion of the distances in respect to the structure shows that the stretching of octahedron around Cu²⁺ is no evidence for a Jahn-Teller-effect.