New copper selenites. Part B: Cu-2(SeO3)(2)center dot H2O and Tl(III)(2)Cu-3(SeO3)(6)

Cu-2(SeO3)(2). H2O and Tl(III)(2)Cu-3(SeO3)(6) were obtained in the course of low-hydrothermal experiments on natrochalcite-type selenate representati ves. The crystal structures were determined by direct methods from single-c rystal X-ray diffraction data collected with a CCD area detector. Cu-2(SeO3 )(2). H2O: space group P2(1)/c, Z = 4, a = 8.409(2) Angstrom, b = 7.508(2) Angstrom, c = 10.511(2) Angstrom, beta = 111.77(1)degrees V = 616.3(2) Angs trom(3), R1 = 0.019. TI(III)(2). Cu-3(SeO3)(6): space group P (1) over bar, Z = 1, a = 4.803(1) Angstrom, b = 9.605(2) Angstrom, c = 9.934(2) Angstrom , alpha = 67.05(2)degrees, beta = 81.41(2)degrees, gamma = 77.96(2)degrees, V = 411.6(2) Angstrom(3), R1 = 0.037.