Single crystals of an organically templated holmium hydrogen phosphate sulfate, [enH(2)](0.5)[Ho(HPO4)(SO4)(H2O)] (en; ethylenediamine) were prepared by hydrothermal reaction and its crystal structure was determined by single crystal X-ray diffraction data. This compound crystallized in the monoclinic system, space group P2(1)/a (No. 14) and the unit cell parameters are a 12.938(5), b = 6.834(3), c = 9.100(2) angstrom, and beta=88.12(2)degrees. The crystal structure is similar to that of [enH(2)](0.5)[Ce(HPO4)(SO4)(H2O)] which had a layered structure built tip by Cc centered polyhedra and HPO4 and SO4 tetrahedra, and the diprotonated ethylenediamine cations were located in the interlayer. For other rare earth elements two types of compounds were obtained tinder hydrothermal conditions. The compounds of R = La, Pr, Nd, Sm and Eu are isostructural with [enH(2)](0.5)[Ce(HPO4)(SO4)(H2O)] and those of Gd, Th, Dy, Er and Yb with [enH(2)](0.5)[Ho(HPO4)(SO4)(H2O)]. The unit cell volumes of these compounds decrease by lanthanide contraction. The compounds of R except La, Sm and Eu exhibited the Curie-Weiss paramagnetic behavior. (C)2010 The Ceramic Society of Japan. All rights reserved
