[Am]Mn(H₂POO)₃: A New Family of Hybrid Perovskites Based on the Hypophosphite Ligand

Abstract

A family of five hybrid ABX perovskites has been synthesized using hypophosphite (HPOO) as the X-site ion. These compounds adopt the general formula [Am]Mn(HPOO), where Am = guanidinium (GUA), formamidinium (FA), imidazolium, triazolium, and dabconium. We explore the diverse structural and phase transition behavior of these materials through single-crystal diffraction measurements and demonstrate contrasting magnetism in two of the phases, Am = GUA and FA, that arises from structural distortions. The results show that hypophosphite perovskites offer a promising platform for generating new functional materials.

Tilts and shifts in molecular perovskites

“…1]. 7,9,16,37,40,47,57,58 This structure features out-of-phase tilts (R 5 − ) of equal amplitude polarised along two axes of the perovskite unit cell and another out-of-phase tilt of different magnitude along the third direction (a − a − b − in Glazer notation). 24 Yet, the tiltdriven C2/c phase is the only structure appearing in all different families, and such common phases seem to be more of an exception than a rule.…”

“…Hypophosphites and dicyanamides show a broad variety of binding angles and their binding arrangements are not restricted to planar, thus leading to the range of distortions observed. 9,45 It is noteworthy that all the bent linkers appear to favour conventional tilts above unconventional tilts, which again may form the basis of simple design rules. To further explore the binding modes of Fig.…”

“…70 ; Ph = phenyl, C 6 H 5 ) all contain the correct ingredients to couple to a M 3 + Jahn-Teller distortion to break the inversion symmetry. 9,14,73 Thus replacement of Mn 2+ with Cu 2+ is likely to give an acentric structure. However, incorporation of Cu in larger molecular perovskites often leads to the preferential adoption of alternative structure types 16,74 and so the realisation of a Cu-containing dicyanamide perovskite may be an experimental challenge.…”

Mix and Match: Organic and Inorganic Ions in the Perovskite Lattice

“…[81,164,175] HP(AX) structures employ many of the ligands we discussed for HP(A) and HP(X) compounds. [176] Although limited, this is already an interesting list including linear and bent ligands as well as ligands with homogeneous or heterogeneous anchoring groups. Since the perovskite backbone is dominated by the BX 3 Figure 5.…”

“…The most recent addition to this list is hypophosphite (H 2 POO − ). [176] Although limited, this is already an interesting list including linear and bent ligands as well as ligands with homogeneous or heterogeneous anchoring groups.…”