Promoting structural distortion to enhance the crystal field strength of Mn(II) in tetrahedral bromide for near-unity yellow emission.

Two zero-dimensional hybrid manganese bromide polymorphs ((DMAPH)MnBr) exhibit single-crystal to single-crystal phase transformation, accompanied by an increase in MnBr tetrahedral bond angle variance (). This structural change leads to an emission redshift due to enhanced crystal field strength, achieving yellow emission with near-unity quantum yield, which highlights its potential for solid-state lighting applications.