Ca2Pd2In and Ca2Pt2In with Monoclinic HT‐Pr2Co2Al Type Structure

The metal‐rich indides Ca2Pd2In and Ca2Pt2In were synthesised from the elements in sealed tantalum ampoules in an induction furnace. Both samples were investigated by X‐ray powder and single crystal diffraction: HT‐Pr2Co2Al type, C2/c, a = 1017.6(5), b = 574.1(3), c = 812.7(3) pm, β = 104.54(2)°, wR2 = 0.0344, 590 F2 values for Ca2Pd2In and a = 1004.3(3), b = 568.9(1), c = 813.1(2) pm, β = 104.25(2)°, wR2 = 0.0435, 654 F2 values for Ca2Pt2In with 25 variables per refinement. The structure contain Pd2 (272 pm) and Pt2 (264 pm) dumb‐bells with a trigonal prismatic coordination for each transition metal atom. These AlB2 related slabs are condensed via common edges. Together the palladium and indium atoms build up three‐dimensional [Pd2In] and [Pt2In] polyanionic networks in which the calcium atoms fill larger channels. The bonding of calcium to the network proceeds via shorter Ca–Pd and Ca–Pt contacts. Ca2Pd2In and Ca2Pt2In are Pauli paramagnets.