Palladium(IV) in an Oxoanionic Environment: The XeF2 Assisted Synthesis of [Pd(S2 O7 )3 ](2.)

For the first time tetravalent palladium is detected, coordinated exclusively by simple oxoanions. Stabilization was achieved by formation of the [Pd(S2 O7 )3 ](2-) complex in which three chelating disulfate groups surround the metal atom. The salt K2 [Pd(S2 O7 )3 ] could only be obtained if the reaction of K2 [PdCl6 ] and neat SO3 was performed in the presence of XeF2 .

Self-assembly of polyoxoselenitopalladate nanostars [Pd₁₅(μ₃-SeO₃)₁₀(μ₃-O)₁₀Na]⁹⁻ and their supramolecular pairing in the solid state

An anionic Pd₁₅-oxo-cluster [Pd₁₅(μ₃-SeO₃)₁₀(μ₃-O)₁₀Na]⁹⁻ has been synthesized. It is the result of an unprecedented self-assembly of Pd(2+) and Na(+) cations, SeO₃²⁻ and oxo anions. It has been found for the first time, that selenito groups can give rise to supramolecular interactions in the solid state with palladium atoms, through the selenium electron lone pairs.

Synthesis, crystal structure and Raman spectrum of K(2)[(Pt(2))(HPO(4))(4)(H(2)O)(2)] containing (Pt(2)) ions

In the crystal structure of the acid platinum phosphate dipotassium di-μ-hydrogenphosphato-bis-[aqua-platinum(III)](Pt-Pt), K(2)[Pt(2)(HPO(4))(4)(H(2)O)(2)], the (Pt(2))(6+) dumbbells within the paddle-wheel complex show Pt-Pt distances of 2.4944 (5) and 2.4892 (5) Å. The pottassium ions are seven-fold coordinated by hydrogenphosphate groups. In the crystal, O-H⋯O hydrogen bonds help to establish the packing. The Raman spectrum was recorded.

Ag(2)PdP(2)O(7)

Disilver(I) palladium(II) diphosphate, Ag(2)PdP(2)O(7), is isotypic with Na(2)PdP(2)O(7). It consists of infinite diphosphato-pallad-ate(II) [Pd(P(2)O(7))(2/2)](2-) ribbons with the Pd(II) ion in an almost square-planar coordination ( symmetry) and the P(2)O(7) group exhibiting 2 symmetry. The [Pd(P(2)O(7))(2/2)](2-) ribbons are linked by distorted [AgO(6)] octa-hedra. (31)P-MAS NMR studies on Ag(2)PdP(2)O(7) are in accordance with one independent site for phospho-rus; its isotropic chemical shift δ(iso) = 21.5 p.p.m. is similar to that of Pd(2)P(2)O(7).

Selenium Oxoanion Compounds of Palladium(II)

Three new palladium compounds, PdSeO3, PdSe2O5, and Na2Pd(SeO4)2, containing selenium oxoanions of both Se(IV) and Se(VI) have been prepared under mild hydrothermal conditions. PdSe2O5 and Na2Pd(SeO4)2 both possess one-dimensional structures. Within the structure of PdSe2O5, [PdO4] square planar building blocks are joined together through diselenite, Se2O52-, anions, and form a zigzag chain along the c axis. In Na2Pd(SeO4)2, [PdO4] units are connected by two selenate, SeO42-, anions, and extend along the a axis to form a [Pd(SeO4)2]2- chain. Na+ cations reside in the space between the [Pd(SeO4)2]2- chains and act as counter cations. Unlike above two compounds, PdSeO3 exhibits a layered structure. In the structure of PdSeO3, [PdO4] units are connected to each other by corner-sharing and form a zigzag chain along the b axis. The chains are further joined together by tridentate selenite, SeO32-, anions to form layers in the [ab] plane that stack along the c axis. Crystallographic data: (193 K; Mo Kalpha, lambda=0.71073 A): PdSeO3, monoclinic, space group P21/m, a=3.8884(5) A, b=6.4170(8) A, c=6.1051(7) A, beta=96.413(2) degrees, V=151.38(3) A3, Z=2; PdSe2O5, monoclinic, space group C2/c, a=12.198(2) A, b=5.5500(8) A, c=7.200(1) A, beta=107.900(2) degrees , V=463.8(1) A3, Z=4; Na2Pd(SeO4)2, triclinic, space group P, a=4.9349(11) A, b=5.9981(13) A, c=7.1512 (15) A, alpha=73.894(4) degrees, beta=86.124(4) degrees, gamma=70.834(4) degrees, V=192.03(7) A3, Z=1.