The new germanates(IV) were synthesized via reaction of GeO2 with AO2 (A=K, Rb, Cs) and the elemental alkaline metals and their crystal structures have been determined from single crystal X-ray data. ß-K4GeO4 / Rb4GeO4 (monoclinic, P21/c , a = 1047.6(3)/1103.2(2), b = 646.5(1)/673.3(1), c = 1048.1(3)/1084.5(2) pm, ß = 112.291(5) / 112.676(4)°, Z = 4) and Cs10Ge2O9 (monoclinic, P21/c , a = 1293.7(2), b = 1148.6(2), c = 1926.4(2) pm, ß = 128.05(8)°, Z = 4) contain isolated, A6Ge3O9 (A = Rb / Cs: monoclinic, P 21/c , a = 663.0(1) / 696.3(2), b = 1346.8(2) / 1403.1(3), c = 1666.6(2) / 1742.8(6) pm, ß = 107.47(2) / 107.88(2)°, Z = 2) cyclotrigermanate ions. In Cs3AlGe2O7 (monoclinic, C2/c, a = 961.5(2), b = 1719.7(2), c = 761.7(1) pm, ß =126.5(1)°, Z = 4) digermanate ions are connected via [AIO4 ] tetrahedra to form ribbons.

The crystal structure of synthetic (NH4)2[B4O5(OH)4] · 2 H2O was determined from single-crystal X-ray diffractometer data. The compound is monoclinic, space group P21 = C 2 2h; the lattice constants are a = 10.691(2)Å, b = 10.646(3) Å, c = 7.223(3)Å, β = 139.4(3)°; the unit cell contains two formula units. The crystal structure was solved from 1190 observed reflections by means of the Patterson method and refined by leastsquares calculations to an index R of 9.2% and Rw of 7.6%. The structure contains isolated polyanions [B4O5(OH)4]2−, similar to those found in the structures of other borates, e.g. borax or tincalconite, but without any mirror plane or twofold axis. The crystallographically different atoms N1 and N2 are coordinated by seven O atoms with distances between 2.83 and 3.40 or 3.37 Å, respectively. Connections between the B – O rings are provided by the NH4 polyedra and by the hydrogen bonding system from the NH4 to the OH groups and to one of the water molecules, thus fo...

Gd 2 (SO 3 ) 3 .3 H 2 O is obtained by passing gaseous SO 2 through a suspension of Gd 2 O 3 in H 2 O at room temperature until a clear solution is formed. Single crystals are obtained by heating to 70(2) o C for 6 days. The compound crystallizes in the triclinic space group P1 with a=6.499(6), b=6.621(3), c=6.954(3), α=110.71(5), β=90.54(3), γ=106.05(1) o and Z=1. The two crystallographically different gadolinium atoms are both coordinated by eight oxygen atoms forming distorted square antiprisms