Network Formation by Square‐planes and Tetrahedra:Polynary Palladiumphosphates M Pd 2 (PO 4 ) 2 ( M = Ca, Cd, Hg), M PdP 2 O 7 ( M = Ca, Sr, Ba, Zn, Hg, Pb), and PbPdSi(P 2 O 7 ) 2 [1]

Starting from PdO, HgO and P 4 O 10 yellow, plate‐like single crystals of HgPdP 2 O 7 were obtained by chemical vapour transport experiments (600 °C → 500 °C, addition of PdCl 2 ). Micro‐crystalline PbPdP 2 O 7 is synthesized by heating ( T max = 700 °C) stoichiometric amounts of PdO, PbO, and phosphoric acid. Using chemical vapour transport experiments (800 °C → 700 °C, addition of PdCl 2 ) brown plate‐like single crystals of PbPdP 2 O 7 were obtained besides yellow needles of PbPdSi(P 2 O 7 ) 2 . Brown, prismatic crystals of HgPd 2 (PO 4 ) 2 with edge‐lengths up to 1 mm were grown by solvothermal reactions of PdO and HgO with conc. H 3 PO 4 (400 °C, 7d, cooling: 1°/h). The structures of all compounds were determined and refined from X‐ray single crystal data (HgPdP 2 O 7 : C 2/ c , a = 14.117(2) Å, b = 4.884(1) Å, c = 8.802(1) Å, β = 100.9(1)°; PbPdP 2 O 7 : Pnma , a = 13.440(1) Å, b = 5.966(1) Å, c = 7.368(1) Å; PbPdSi(P 2 O 7 ) 2 : P 2 1 / m , a = 4.593(1) Å, b = 17.169(1) Å, c = 6.435(1) Å, β = 101.71(1)°; HgPd 2 (PO 4 ) 2 : Fddd , a = 6.955(1) Å, b = 11.342(1) Å, c = 15.840(1) Å). According to IP Guinier‐photographs microcrystalline powders of M Pd 2 (PO 4 ) 2 ( M = Cd, Ca) and M PdP 2 O 7 ( M = Ca, Sr, Ba, Zn) are isotypic to HgPd 2 (PO 4 ) 2 and PbPdP 2 O 7 , respectively. 31 P‐MAS‐NMR studies on HgPdP 2 O 7 and CaPd 2 (PO 4 ) 2 are in accordance with one independent site for phosphorus. Their chemical shifts were determined to δ iso = 24.2 , δ aniso = 83.0 , η = 0.43 for HgPdP 2 O 7 and δ iso = 32.1 , δ aniso = 36.0 , η = 0,84 for CaPd 2 (PO 4 ) 2 .