Anion Recognitions via Cocrystallizations with Organic π-Acids in the Efficient Self-Assembly of Nanoscopic One-Dimensional Molecular Chains (Wires)

Abstract

The self-assembly of various anions (e.g., thiocyanate, nitrite/nitrate, sulfite/sulfate, tetrahalometallates, etc.) with prototypical π-acids (consisting of cyano-and nitrosubstituted pyrazine and benzene, as well as tetracyanoethylene) occurs rapidly and selectively to yield a series of novel one-dimensional structures. The wire-like molecular chains all consist of parallel stacks of π-acids and alternate anions of different sizes and shapes that establish the dihedral angles R and φ sufficient to define these unique structures. Analogy of such linear arrays to nanoscopic wires is reinforced by the protective sheath of countercations that are completely arrayed around the linear cores. The critical feature of these efficient self-assemblies is shown to derive from anion/π-recognitions via charge-transfer forces between the electron-rich anions acting as electron donors and the electron-poor π-acids acting as electron acceptors to spontaneously generate synthons according to Mulliken theory.

Tuning of the anion–π interaction

“…For two complexes, where the BSSE energies are large (18 and 19), we have carried out BSSE-corrected geometry optimizations, and we have obtained comparable results, very similar interaction energies and slightly larger equilibrium distances. For complexes where the nitrogen atoms of s-triazine are forming covalent bonds with silver and boron (20)(21)(22)(23)(24)(25)(26)(27)(28), the BSSE correction has not been applied. Some interesting points can be extracted from the geometrical results.…”

“…In addition, the favorable interaction of anions with p-acidic rings, namely anion-p interaction [19][20][21], has been extensively studied theoretically [22], and its importance has been corroborated by a great deal of experimental work. For instance, a new family of anion receptors based on anionp interactions has emerged [23][24][25][26][27][28][29][30][31][32]. Moreover, the design and synthesis of highly selective anion channels [33][34][35][36][37][38][39][40] Electronic supplementary material The online version of this article (doi:10.1007/s00214-012-1219-6) contains supplementary material, which is available to authorized users.…”

“…Interaction energies and cooperativity energies with BSSE correction (E BSSE and E coop , respectively, in kcal/mol), equilibrium distances (R e and R rB , in Å ) and their variation (DR e and DR rB , in Å ) at the RI-MP2/aug-cc-pVDZ level of theory for complexes[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] …”

Aromatische Ringe in chemischer und biologischer Erkennung: Energien und Strukturen

“…[307] Der [311] mit dreifüßigen Rezeptoren [312] und einem Triazin enthaltenen Käfigmolekül [313] identifiziert. Vor Kurzem wurde auch über Anion-p-Wechselwirkungen von F À mit elektronenreichen Arenen in einem dreifüßigen Käfigmolekül berichtet.…”

Anion-π Interactions in Supramolecular Chemistry and Catalysis

“…the attractive noncovalent force between an electron-deficient π-system and an anionic moiety [34,35], has also been recognized as a non-covalent bonding interaction. Its nature has been described by a plethora of theoretical studies [36][37][38][39] in addition to an increasing amount of experimental investigations [40][41][42][43][44]. Anion-π interactions are expected to become noticeable players in fields as diverse as medicine, environmental chemistry and biochemical processes [31,[45][46][47].…”