Synthesis and crystal structures of yttrium sulfates Y(OH)(SO4), Y(SO4)F, YNi(OH)(3)(SO4)-II and Y2Cu(OH)(3)(SO4)(2)F center dot H2O

Y(OH)(SO4), Y(SO4)F, YNi(OH)(3)(SO4)-II and Y2Cu(OH)(3)(SO4)(2)F . H2O are obtained from hydrothermal reactions at 380 degrees C under a pressure of 2 10 MPa. Their crystal structures were refined from single-crystal X-ray dif fraction data. The four compounds have the following space groups and unit cells: Y(OH)(SO4) P2(1)/n, a = 7.9498(6), b = 10.9530(9), c = 8.1447(6) Ang strom, beta = 93.764(1)degrees; Y(SO4)F, Pnma, a = 8.3128(9), b = 6.9255(7) , c = 6.3905(7) Angstrom; YNi(OH)(3)(SO4)-II, Pnma, a = 6.9695(8), b = 7.26 15(8), c = 10.292(1) Angstrom; Y2Cu(OH)(3)(SO4)(2)F . H2O, P2(1)/n, a = 11. 6889(7), b = 6.8660(4), c = 12.5280(8) Angstrom, beta = 97.092(1)degrees. T he coordination environments of the yttrium atoms in the four structures va ry from highly irregular 6 + 2, 6 + 3, 7 + 1 coordination polyhedra to rela tively regular dodecahedra. (C) 2000 Editions scientifiques et medicales El sevier SAS. All rights reserved.