Exploiting polymorphism in second sphere coordination: thermal transformation, NLO properties and selective mechanochemical synthesis

Abstract

The racemic organic building block L acting as a first sphere ligand yields a new second sphere adduct [LH]⁺·[FeCl₄]⁻ crystallizing as racemic polymorphs α and β. Solid-state DFT calculations show that polymorph β is the kinetic adduct as observed experimentally. The β-phase crystallizes in the polar space group Pna2₁ and displays NLO properties. Mechanochemical synthesis yields only the β-phase.