Synthesis of Butadiynyl-Strapped Corona[6]arenes and Their Selective Anion Binding Properties

Abstract

A number of butadiynylene-strapped O6-corona­[6]­arenes were synthesized straightforwardly through intramolecular oxidative homocoupling of O6-corona­[6]­arenes, which contained at least two N-propargyl-phthalimide segments. The mono-macrocyclic reactants were prepared from the reaction between 3,6-dichlorotetrazine and N-propargyl-3,6-dihydroxyphthalimide and another 1,4-dihydroxybenzene derivative with roughly a 3:2:1.3–1.5 ratio in a one-pot reaction manner. The synthesized butadiynylene-strapped corona[3]­arene[3]­tetrazines acted as highly selective electron-deficient macrocyclic hosts to form 1:1 complexes with thiocyanate in solution, and the association constant (K a) was up to 1390 M–1. The anion−π noncovalent interactions provided the driving force for host–guest complexation.

Carbazole sulfonamide-based macrocyclic receptors capable of selective complexation of fluoride ion

“…6 , one fluoride ion was captured by two sulfonamide NH groups (N⋯F distances of 2.650 and 2.641 Å, respectively, and the corresponding N–H⋯F angles of 160.4 and 169.1°) from two adjacent host molecules. This disparity in the binding stoichiometry between solution phase and solid state had been previously reported, 36–40 likely resulting from molecular packing effect in the latter case. 37 …”

“…6, one uoride ion was captured by two sulfonamide NH groups (N/F distances of 2.650 and 2.641 A, respectively, and the corresponding N-H/F angles of 160.4 and 169.1 ) from two adjacent host molecules. This disparity in the binding stoichiometry between solution phase and solid state had been previously reported, [36][37][38][39][40] likely resulting from molecular packing effect in the latter case. 37 In order to shed more light on the nature of the formed complex between macrocycle 1 and uoride ion, density functional theory (DFT) calculations were performed at the B3LYP/6-311++G(d,p) level under the polarizable continuum model (PCM) using CH 3 CN as a solvent in the Gaussian 16 package.…”

Anion‐π Interaction for Molecular Recognition of Anions: Focus on Cooperativity with Hydrogen Bonding

“…The bicyclic compound 19, recently prepared by the same team, displays a remarkable selectivity towards the SCNanion. [94] Figure 6 General structure of coronarenes (Reprinted with permission from Springer Nature: Springer, Science China Chemistry [91] ,…”

“…Copyright 2018) and examples of coronarene isomers reported by the team of Wang. [92][93][94] Finally, Stoddart et al recently described the design and synthesis the "Tetrazinebox" 20, a structurally transformative tetrazine-containing tetracationic cyclophane, which seems to be of great interest for the design of future molecular machines. (Figure 7).…”

“…[93] The bicyclic compound 19, recently prepared by the same team, displays a remarkable selectivity towards the SCN À anion. [94] Finally, Stoddart et al recently described the design and synthesis the ''Tetrazinebox'' 20, a structurally transformative tetrazine-containing tetracationic cyclophane, which seems to be of great interest for the design of future molecular machines (Figure 7). [96]…”