Ion‐Pairing Assemblies of Deprotonated Meso ‐Hydroxyporphyrins as π‐Electronic Anions

Charged π‐electronic systems provide ion‐pairing assemblies, which would exhibit fascinating properties by appropriate modifications. Deprotonation of acid‐unit‐appended π‐electronic systems, such as meso ‐hydroxyporphyrins (MHPs), enables the formation of π‐electronic anions, for which the substituents modulate the electronic states and assembly modes. In this study, MHP Pt II complex anions, bearing electron‐donating phenyl groups and electron‐withdrawing C 6 F 5 groups, formed various ion pairs in combination with cations, including triazatriangulenium and porphyrin Au III complex cations. Single‐crystal X‐ray analysis revealed solid‐state ion‐pairing assemblies of the MHP Pt II complex anions with charge‐by‐charge packing modes, where the arrangements of the components were dependent on the peripheral substituents and coexisting countercations. Hirshfeld surface analysis and energy decomposition analysis (EDA) calculations revealed that ion‐pairing assembly modes were mainly governed by i π– i π interactions between the MHP Pt II complex anions and countercations.