Why do polymorphs form? A single crystal phase transformation from weak dipolar interactions to a sixfold phenyl embrace

Abstract
The crystal structures of the α- and β-polymorphs of GeHPh3 are reported along with mechanistic studies of the transformation by DSC and optical microscopy. DSC results also reveal new metastable phases for XHPh3 (X = Si, Sn). The results highlight the significance of the sixfold phenyl embrace (6PE) as an organising motif.