The new quaternary palladium chalcogenides, Rb2ZrPd3S6, Rb2HfPd3S6 and Cs2ZrPd3Se6 have been prepared from elemental powders through alkali metal halide flux methods and they are structurally characterized by single crystal X-ray diffraction techniques. They adopt two-dimensional layered structures. In these layers, there are two basic building blocks centered by metals. The early transition groups 4 metals (Zr, Hf) are surrounded by six Q (S, Se) atoms in a trigonal prismatic fashion and Pd atoms are coordinated to four square plane Q atoms. The structural variations of these phases come from the different connecting mode of these building blocks.
<br>Two MQ6 units are bridged by two Pd atoms to form the basic repeating units, M2Pd2Q12. These units are linked together to complete the infinite anionic two-dimensional layer, 2¦∞[MPd3Q62-]. These layers stack on top of each other and the Alkali metal cations reside between the layers to satisfy the charge neutrality and complete the three-dimensional structure.
<br>A series of new quaternary group 4 metal palladium chalcogenides, A2MPd3Q6 (A = Rb, Cs; M = Zr, Hf; Q = S, Se) have been prepared from elements with the use of alkali metal halide fluxes and they are structurally characterized by single crystal X-ray diffraction methods. They are isostructural and the structure of the title compounds consists of anionic 2¦∞[MPd3Q62-] slabs and alkali metal ions. In the slab, the group 4 metals, M are surrounded by six Q atoms in a trigonal prismatic fashion and the Pd atoms are coordinated to four Q atoms of a square plane. Two hexagons made of six edge-sharing square planar PdQ4 are interconnected by two trigonal prismatic MQ6 to form the basic repeating unit, M2Pd12Q28. These are linked together to form the infinite anionic two-dimensional 2¦∞[MPd3Q62-] slabs. These slabs stack on top of each other the alkali metal cations reside between the slabs to satisfy the change neutrality and complete the three-dimensional structure. No strong Q-Q bonding interaction is found in this phase and the charge valence of the title compounds should be described as [A+]2[M4+][Pd2+]3[Q2-]6 (A = Rb, Cs; M = Zr, Hf; Q = S, Se).
