Synthesis of Cyclical Diamine Templated Uranium Sulfates

Abstract

The hydrothermal synthesis of uranium sulfates in the presence of a series of structurally related organic templating agents has been investigated. Piperazine, 2-methylpiperazine, and 1,4-diazabicyclo[2.2.2]octane, each of which is based upon the same six-membered cyclical diamine, exhibit different point symmetries and hydrogen-bonding characteristics. Small changes in the template structure result in marked differences in the reaction product. Three new compounds were synthesized and structurally characterized, [N2C4H12][UO2(H2O)(SO4)2], [N2C5H14][UO2(H2O)(SO4)2], and [N2C6H14][UO2(H2O)(SO4)2]. The inorganic framework of each compound was found to be dependent on the template structure. [N2C4H12][UO2(H2O)(SO4)2] consists of one-dimensional [UO2(H2O)(SO4)4/2]∞ 2- chains, which hydrogen bond to one another to form quasi two-dimensional layers. One-dimensional chains are observed in [N2C5H14][UO2(H2O)(SO4)2]. These chains, which have the formula [UO2(H2O)(SO4)4/2(UO2(H2O)(SO4)2)]∞ 4- are unprecedented in uranium chemistry. Two-dimensional layers are observed in [N2C4H12][UO2(H2O)(SO4)2]. Each uranyl [UO2]2+ unit is bound to one water molecule and four bridging sulfate tetrahedra.

Topologically and geometrically flexible structural units in seven new organically templated uranyl selenates and selenite–selenates

“…4 ] nÀ tetrahedra (T¼S, Se, P, As). They have been observed first in the structure of Mn[(UO 2 ) (SO 4 ) 2 (H 2 O)](H 2 O) 5 [39] and later in a number of amine-templated uranyl sulfates [40][41][42][43][44][45] [50]. Fig.…”

Synthesis and crystal structure of a new neodymium(III) selenate-selenite: Nd2(SeO4)(SeO3)2(H2O)2

“…This research area is largely dominated by metal phosphates and aluminosilicate zeolites [1,2]. A few organically templated metal sulfates have also been reported recently [3][4][5][6][7][8][9][10][11][12][13]. As for the oxy-anions of Se, an organically templated 2D zinc selenite was first reported by Harrison et al.…”

Synthesis, Crystal Structure, and Magnetic Properties of a Three‐Dimensional Hydroxide Sulfate: Mn5(OH)8SO4

“…[28] O. Hare et al have synthesized several uranium sulfates, one of which has a 3D structure. [29][30][31] Metal sulfates without entrained organic cations also exhibit interesting catalytic, ion-exchange, and magnetic properties, and they have higher thermal stability relative to metal sulfate hybrids.…”