Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

Abstract

Ion pairs of N-(2,6-dimethylphenyl)-substituted triazatriangulenium (TATA⁺) cation with various counteranions were synthesized to investigate the interactions for the bulky cation. Single-crystal X-ray analysis of the TATA⁺ ion pairs revealed solid-state ion-pairing assemblies without stacking at the cationic π-planes. The TATA⁺ cation showed counteranion-dependent assembly structures, with smaller counteranions located at the top of TATA⁺ and bulkier counteranions displaced from the TATA⁺ plane to interact with the surrounding TATA⁺.

Keywords: charged π-electronic systems; ion pairs; single-crystal X-ray analysis; solid-state assemblies; triazatriangulenium cation.

Figure 1

Triazatriangulenium cations 1a⁺ and 1b⁺.

Figure 2

Synthesis of triazatriangulenium ion pairs 2⁺-X⁻ (X⁻ = BF₄⁻, PF₆⁻, B(C₆F₅)₄⁻, and PCCp⁻).

Figure 3

Single-crystal X-ray structures of (a) 2⁺-Cl⁻, (b) 2⁺-BF₄⁻, (c) 2⁺-PF₆⁻, (d) 2⁺-B(C₆F₅)₄⁻, and (e) 2⁺-PCCp⁻ as (i) packing structures and (ii) enlarged views for the columnar structures. In (i), cation and anion are represented in cyan and magenta colors, respectively. In (ii), brown, pink, yellow, blue, yellow green, orange, and green (spherical) refer to carbon, hydrogen, boron, nitrogen, fluorine, phosphorus, and chlorine, respectively.

Figure 4

Hirshfeld surface analysis mapped with d_norm of closely contacted two 2⁺ in (a) 2⁺-BF₄⁻ and (b) 2⁺-PF₆⁻. Atom color code: brown, pink, and blue refer to carbon, hydrogen, and nitrogen, respectively.

Figure 5

Hirshfeld surface analysis mapped with d_norm of closely contacted ion pairs: (a) 2⁺-Cl⁻, (b) 2⁺-BF₄⁻, and (c) 2⁺-PF₆⁻. Atom color code: yellow, green, orange, and green (spherical) refer to boron, fluorine, phosphorus, and chlorine, respectively.

Figure 6

(i) Single-crystal X-ray structures and (ii) interaction energies for the pairs (a) 2⁺-Cl⁻, (b) 2⁺-BF₄⁻, and (c) 2⁺-PF₆⁻. In (i), the cation and the anion are represented in cyan and magenta colors, respectively.

Figure 7

Hirshfeld surface analysis mapped with d_norm of closely contacted ion pairs: (a) 2⁺-B(C₆F₅)₄⁻ and (b) 2⁺-PCCp⁻. Atom color code: brown, yellow, blue, and green refer to carbon, boron, nitrogen, and fluorine, respectively.

Figure 8

(i) Single-crystal X-ray structures and (ii) interaction energies for the pairs for (a) 2⁺-B(C₆F₅)₄⁻ and (b) 2⁺-PCCp⁻. In (i), the cation and the anion are represented in cyan and magenta colors, respectively.