Präparation und röntgenographische Charakterisierung der Verbindungen Ca3M2Ga2 (M = Pd,Pt) und Ca3M2Ga3 (M = Rh,Ir)

Preparation and Crystal Structures of the Compounds Ca₃Pd₂Ga₂, Ca₃Pt₂Ga₂, Ca₃Rh₂Ga₃, and Ca₃Ir₂Ga₃ The new compounds Ca₃Pd₂Ga₂, Ca₃Pt₂Ga₂, Ca₃Rh₂Ga₃, and Ca₃Ir₂Ga₃ were prepared by heating appropriate mixtures of the elements under an Argon-atmosphere. The results of the structure analysis of single crystals by means of X-ray diffraction are given in the section “Inhaltsübersicht”. Ca₃Pd₂Ga₂ and Ca₃Pt₂Ga₂ are isotypic and form the Y₃Rh₂Si₂ type structure (Pbcm), where the platinium metals have a trigonal environment consisting of Ga-atoms. The isotypic compounds Ca₃Rh₂Ga₃ and Ca₃Ir₂Ga₃ (Pbcm) form a new type of structure, which is related to the Y₃Rh₂Si₂ type with a distorted tetrahedral surrounding of Ga-atoms for Rh (resp. Ir).