Controlled Structural Variations in Templated Uranium Sulfates

A series of experiments in the UO2(CH3CO2)2·2H2O/H2SO4/1-(2-aminoethyl)piperazine/H2O system were conducted
to determine the effects of variation in initial reactant concentrations on the reaction products. Several reaction gels
were produced, in which the composition varied from 16:80:4:500 UO2(CH3CO2)2·2H2O/H2SO4/1-(2-aminoethyl)piperazine/H2O to 4:92:4:500 UO2(CH3CO2)2·2H2O/H2SO4/1-(2-aminoethyl)piperazine/H2O. Single crystals of two
new organically templated uranium sulfates, [N3C6H18]2[(UO2)5(H2O)(SO4)8]·5H2O and [N3C6H18][(UO2)2(H2O)(SO4)3(HSO4)]·4.5H2O, were isolated. Both compounds exhibit structures in which the inorganic frameworks are two-dimensional and the protonated amines reside between layers, participating in extensive hydrogen bonding. The
composition and structure of each compound is dependent on the nature of the starting concentrations. Crystal
data:  for [N3C6H18]2[(UO2)5(H2O)(SO4)8]·5H2O, monoclinic, space group P21/n (No. 14), a = 21.5597(3) Å, b =
10.2901(2) Å, c = 22.8403(3) Å, β = 96.7436(7)°, and Z = 4; for [N3C6H18][(UO2)2(H2O)(SO4)3(HSO4)]·4.5H2O,
monoclinic, space group P21/a (No. 14), a = 15.7673(4) Å, b = 10.5813(3) Å, c = 16.7710(5) Å, β = 99.9216(9)°, and Z = 4.