Ion-pairing π-electronic systems: ordered arrangement and noncovalent interactions of negatively charged porphyrins

Abstract

In this study, charged π-electronic species are observed to develop stacking structures based on electrostatic and dispersion forces. iπ–iπ Interaction, defined herein, functions for the stacking structures consisting of charged π-electronic species and is...

Ion-pairing assemblies of heteroporphyrin-based π-electronic cation with various counteranions

“…Small electrostatic repulsion forces were effective in stabilizing the stacked 1ni + dimers. On the other hand, the synergetic i π– i π interaction 4 between 1ni + and PCCp − units was suggested by E es and E disp (−61.14 and −115.23 kcal mol −1 , respectively).…”

“…2 The introduction of charges to the π-electronic molecules results in significant contributions of electrostatic forces, which induce attraction and repulsion between oppositely and identically charged species, respectively. 3,4 Dispersion forces can overcome repulsive forces and cause identically charged species to be located close to each other. Thus, the arrangement of charged π-electronic systems can be modulated by charge-by-charge and charge-segregated assembling modes, with the stacking of oppositely and identically charged species, respectively.…”

Tetracyanocyclopentadienide-Based Stable Poly(aromatic) Anions

“…Different from traditional charged species, aromatic ions tend to form well-organized, dimension-controlled assemblies through electrostatic and π–π interactions. Promising properties for functional electronic and optical devices have been demonstrated. − As such, synthetic efforts to introduce new categories of aromatic ions are especially attractive. However, in all previous studies, no aromatic anion-based polyelectrolytes have been reported.…”

“…Along this line, we were attracted to the possibility to incorporate tetracyanocyclopentadienide (TCCp)-based aromatic anions in polynorbornene structures through an envisioned ring-opening metathesis polymerization (ROMP; Scheme ). In addition to identifying a viable synthesis compatible with charge-containing moieties during each synthetic step to construct monomers, this task needs to explore whether such charged monomers can be effectively tolerated by metathesis polymerization given their high propensity toward intrinsic stacking , and the coordinative nature of σ-CN unit in anionic TCCp structures. − If successful, this type of synthetic methodology will open access to a new class of polyelectrolyte structures based on aromatic anions.…”

“…It is likely due to the instabilities of traditional π-electronic anion species. Pentacyanocyclopentadienide (PCCp – ) and its derivatives (TCCp – ) bearing electron-withdrawing cyano substituents have recently emerged ,, and have been studied in ion-pair extraction, phase-transfer catalysis, and supramolecular assemblies. , Taking advantage of the chemical stability of this class of aromatic anions, we wish to report herein the development of the first aromatic anion-containing polyelectrolytes, polynorbornene-TCCp (PNb-TCCp) with tetrabutylammonium (TBA) as the countercation. A highly efficient synthetic pathway was developed to access norbornene derivative-based structural modules carrying TBA:TCCp moieties.…”