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 K alpha, lambda = 0.71073 A): PdSeO3, monoclinic, space group P2(1)/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) A(3), 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) A(3), Z = 4; Na2Pd(SeO4)(2), triclinic, space group P $$($) over bar, 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) A(3), Z = 1.