New Variants of (110)‐Oriented Layered Lead Bromide Perovskites, Templated by Formamidinium or Pyrazolium

We acknowledge support from the University of St Andrews, the China Scholarship Council (studentship to YYG) and Leverhulme Trust (RPG-2018-065). Four new hybrid lead(II) halide perovskites, γ-(FA)2PbBr4, (FA)1.5(AA)0.5PbBr4, (PY)(GA)PbBr4 and (PY)(TZ)PbBr4 ((FA)=formamidinium, (AA)=acetamidinium, (PY)=pyrazolium, (GA)=guanidinium and (TZ)=1,2,3-triazolium), adopt (110)-oriented layered perovskite structures. While (PY) is found to template the formation of ‘conventional’ (110)-oriented structure types (i. e. containing staggered [PbBr4]∞ layers), (FA) is shown to facilitate formation of much less common variants based 3 : 1 ordering of the interlayer species or 3×2 step-like corrugation of the perovskite-like layers themselves. Postprint