Single crystals of Eu(ClO4)(3) have been obtained by slow dehydration of a
hydrous product prepared by the reaction of Eu2O3 with HClO4. The crystal s
tructure (hexagonal, P6(3)/m, Z = 2, a = 924.96(9), c = 574.86(8) pm) consi
sts of tricapped trigonal [EuO9] prisms and [ClO4] tetrahedra. One of the o
xygen atoms in the ClO4 group does not coordinate to Eu3+ and points toward
s the empty channel which runs in the direction [001].