Wright A. J., Attfield J. P.
Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Inorg Chem. 1998 Jul 27;37(15):3858-3861. doi: 10.1021/ic980212l.
The crystal structure, magnetic properties, and ion-exchange behavior of RbMnHP(3)O(10) have been determined. The crystal structure (a = 12.1866(3) Å, b = 8.3586(2) Å, c = 9.0763(3) Å, beta = 109.067(1) degrees, space group C2/c), determined from X-ray powder diffraction, is of NH(4)FeHP(3)O(10) type, consisting of hydrogen triphosphate anions linking Jahn-Teller distorted Mn(III)O(6) octahedra around Rb(+) cations. Magnetic susceptibility measurements and low-temperature neutron powder diffraction show that RbMnHP(3)O(10) behaves as a Curie-Weiss paramagnet at high temperatures and orders antiferromagnetically below a Néel temperature of 10 K. The magnetic structure is commensurate with the nuclear cell, and the collinear antiferromagnetic structure has magnetic symmetry group P(C)()2/c' with spins of 3.82(6) &mgr;(B) lying in the ac plane. Exchange of H(+) for Li(+) has not proved possible without a breakdown of the RbMnHP(3)O(10) framework due to strong symmetric hydrogen bonding between triphosphate anions.
已确定RbMnHP(3)O(10)的晶体结构、磁性和离子交换行为。由X射线粉末衍射确定的晶体结构（a = 12.1866(3) Å，b = 8.3586(2) Å，c = 9.0763(3) Å，β = 109.067(1)°，空间群C2/c）为NH(4)FeHP(3)O(10)型，由围绕Rb(+)阳离子的Jahn-Teller畸变Mn(III)O(6)八面体连接的三磷酸氢根阴离子组成。磁化率测量和低温中子粉末衍射表明，RbMnHP(3)O(10)在高温下表现为居里-外斯顺磁体，在低于10 K的奈尔温度下呈反铁磁有序。磁结构与核单元相称，共线反铁磁结构的磁对称群为P(C)()2/c'，自旋为3.82(6) μ(B)，位于ac平面。由于三磷酸根阴离子之间强烈的对称氢键作用，在不破坏RbMnHP(3)O(10)骨架的情况下，用Li(+)交换H(+)已被证明是不可能的。
