Structural Features in Some Layered Hybrid Copper Chloride Perovskites: ACuCl4 or A2CuCl4

We present three new hybrid copper(II) chloride layered perovskites of generic composition ACuCl(4) or A(2)CuCl(4), which exhibit three distinct structure types. (m-PdH2)CuCl4 (m-PdH22+ = protonated m-phenylenediamine) adopts a Dion-Jacobson (DJ)-like layered perovskite structure type and exhibits a very large axial thermal contraction effect upon heating, as revealed via variable-temperature synchrotron X-ray powder diffraction (SXRD). This can be attributed to the contraction of an interlayer block, via a slight repositioning of the m-PdH22+ moiety. (3-AbaH)(2)CuCl4 (3-AbaH(+) = protonated 3-aminobenzoic acid) and (4-AbaH)(2)CuCl4 (4-AbaH(+) = protonated 4-aminobenzoic acid) possess the same generic formula as Ruddlesden-Popper (RP) layered perovskites, A(2)BX(4), but adopt different structures. (4-AbaH)(2)CuCl4 adopts a near-staggered structure type, whereas (3-AbaH)(2)CuCl4 adopts a near-eclipsed structure type, which resembles the DJ rather than the RP family. (3-AbaH)(2)CuCl4 also displays static disorder of the [CuCl4](infinity) layers. The crystal structures of each are discussed in terms of the differing nature of the templating molecular species, and these are compared to related layered perovskites. Preliminary magnetic measurements are reported, suggesting dominant ferromagnetic interactions.

Automated summary

Three new hybrid copper(II) chloride layered perovskites with distinct structures are presented in this study. The differences in structure are attributed to the nature of the templating molecular species used. Preliminary magnetic measurements indicate dominant ferromagnetic interactions in these materials.