LAUSR

Abstract Five uranyl methacrylate complexes with monovalent cations have been synthesized via isothermal room temperature evaporation. The crystal structures of these compounds, [Li(H2O)2][UO2(macr)3]·2Hmacr (1, macr denotes the methacrylate anion CH2 C(CH3)COO−), Na[UO2(macr)3]·H2O (2), Rb[UO2(macr)3] (3), Tl[UO2(macr)3] (4) and Cs[UO2(macr)3] (5), were determined by single crystal X-ray diffraction. In 1–5, the main uranyl-containing structural unit is the [UO2(macr)3]− complex. Variation of the size and nature of the monovalent cations strongly influences the composition and the structure of the compounds. π-interactions between the methacrylate anions, which were previously reported in the crystal structures of [R(H2O)6][UO2(CH2C(CH3)COO)3]2·8H2O (R = Mg or Zn), were observed in 1 and 2 as well, and may play an important structure-directing role. The crystals of 3, 4 and 5 are lacking inversion centers and should exhibit non-linear optical (NLO) properties as well as the previously reported NH4[UO2(macr)3] and K[UO2(macr)3] complexes. The second harmonic generation response of tris(methacrylato)uranylates with monovalent cations (except Tl) has been measured by the powder technique and discussed with respect to previously reported data on the acrylate analogs.