Ca3Al2B8O18: borate with a graphene-like layer featuring two types of topological six-membered rings induced by [AlO4] units

Abstract

A novel borate Ca₃Al₂B₈O₁₈, with two types of topological six-membered rings (6-MRs) in its graphene-like layer, was successfully fabricated by introducing [AlO₄] tetrahedra. The 6-MRs [B₅AlO₁₇] in Ca₃Al₂B₈O₁₈ can be identified as unique ones, and Ca₃Al₂B₈O₁₈ exhibits a new fundamental building block [B₈O₁₉] greatly enriching the structural diversity of B–O configurations.