Perchlorato complexes of rare-earth elements: Syntheses and crystal structures of Lu(ClO4)(3) center dot 3H(2)O, Er(ClO4)(3) center dot H2O, and Sc(OH)(ClO4)(2) center dot H2O

Single crystals of Lu(ClO4). 3 H2O were obtained by slow dehydration of Lu( ClO4)(3). 6 H2O at 140 degrees C under flowing argon. The compound crystall izes in the triclinic crystal system (P1, Z = 2, a = 750.3(1), b = 838.4(1) , c = 1054.6(2) pm, alpha = 79.77(2)degrees, beta = 79.18(2), gamma = 63.83 (2), R-all = 0.0426) with Lu3+ eightfold coordinated by oxygen atoms, which belong to five ClO4- groups and three H2O molecules. The [LuO8] polyhedra and ClO4 groups are connected to form chains which are held together only v ia hydrogen bridges. Er(ClO4)(3). H2O can also be prepared by dehydration o f the respective hexahydrate but only at higher temperature and under vacuu m. The triclinic compound (P (1) over bar, Z = 2, a = 678.31(9), b = 783.4( 1), c = 955.9(1) pm, alpha = 77.29(1)degrees, beta = 75.71(1)degrees, gamma = 78.31(1)degrees, R-all = 0.0292) contains Er3+ ions which are coordinate d by seven C104 groups and one H2O molecule. The linkage of the [ErO8] poly hedra and ClO4- tetrahedra results in a three-dimensional network. Attempts to dehydrate Sc(ClO4)(3). 6 H2O led to the basic perchlorate Sc(OH)(ClO4)( 2). H2O. In the monoclinic structure (P2(1)/n, Z = 4, a = 942.8(1), b = 735 .16(8), c = 1157.9(2) pm, beta = 93.76(2)degrees, R-all = 0.0579), Sc3+ is surrounded by six oxygen atoms which belong to three ClO4- ions, two OH- gr oups and one H2O molecule. These octahedra are connected via common edges w hich are formed by the OH- groups to pairs according to [Sc-2(OH)(2)(ClO4)( 6)(H2O)(2)](2-). Four of the six ClO4- groups link the pairs to two-dimensi onal infinite sheets, which are held together via hydrogen bonds.