Issue 9, 2021

Tilt and shift polymorphism in molecular perovskites


Molecular perovskites, i.e. ABX3 coordination polymers with a perovskite structure, are a chemically diverse material platform for studying fundamental and applied materials properties such as barocalorics and improper ferroelectrics. Compared to inorganic perovskites, the use of molecular ions on the A- and X-site of molecular perovskites leads to new geometric and structural degrees of freedom. In this work we introduce the concept of tilt and shift polymorphism, categorising irreversible perovskite-to-perovskite phase transitions in molecular perovskites. As a model example we study the new molecular perovskite series [(nPr)3(CH3)N]M(C2N3)3 with M = Mn2+, Co2+, Ni2+, and nPr = n-propyl, where different polymorphs crystallise in the perovskite structure but with different tilt systems depending on the synthetic conditions. Tilt and shift polymorphism is a direct ramification of the use of molecular building units in molecular perovskites and as such is unknown for inorganic perovskites. Given the role of polymorphism in materials science, medicine and mineralogy, and more generally the relation between physicochemical properties and structure, the concept introduced herein represents an important step in classifying the crystal chemistry of molecular perovskites and in maturing the field.

Graphical abstract: Tilt and shift polymorphism in molecular perovskites

Supplementary files

Article information

Article type
08 Apr 2021
14 Jun 2021
First published
16 Jun 2021
This article is Open Access
Creative Commons BY license

Mater. Horiz., 2021,8, 2444-2450

Tilt and shift polymorphism in molecular perovskites

S. Burger, S. Grover, K. T. Butler, H. L. B. Boström, R. Grau-Crespo and G. Kieslich, Mater. Horiz., 2021, 8, 2444 DOI: 10.1039/D1MH00578B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity