The Complete Series of Lanthanoid-Chloranilato Lattices with Dimethylsulfoxide: Role of the Lanthanoid Size on the Coordination Number and Crystal Structure

Abstract

We report the synthesis, structural and magnetic characterization of the complete series of lanthanoid-based chloranilato 2D lattices with dimethylsulfoxide (dmso) formulated as: [Ln2(C6O4Cl2)3(dmso)6] with Ln = La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7) and Tb(8) or [Ln2(C6O4Cl2)3(dmso)4]·2dmso·2H2O with Ln = Dy(9), Ho(10), Er(11), Tm(12) and Yb(13); C6O4Cl22− = dianion of 3,6-dichloro-2,5-dihydroxy-1,4-benzoquinone = chloranilato. Single crystal X-ray analysis shows that the largest Ln(III) ions (La–Tb, 1–8) crystallise in the monoclinic P21/n space group (phase I), whereas the smallest ones (Dy–Yb, 9–13) crystallise in the triclinic P-1 space group (phase II). Both phases show a (6,3)-2D network with the typical hexagonal honeycomb lattice, although phase I presents important distortions, resulting in rectangular cavities with a brick-wall orientation. The largest ions (phase I) show a coordination number of nine with a capped square antiprismatic geometry in contrast to the smallest ions (phase II) that present a coordination number of eight with a triangular dodecahedral geometry. Magnetic measurements show that all the Ln(III) ions are magnetically well isolated, leading to the presence of a field induced single-ion magnet behaviour in the Er derivative, with an energy barrier of 23(2) K for DC fields of 20, 50 and 100 mT.