Dimeric Resorcin[4]arene Capsules in the Solid State

Abstract

Supramolecular chemistry research is focused on the study of weak non‐covalent intermolecular — that is, supramolecular — interactions as the driving force in self‐assembly and molecular recognition. Dimeric resorcin[4]arenes capsules have been a focus of our research for the last 15 years. This review describes the solid state complexation studies of unsubstituted phenolic resorcin[4]arenes and pyrogall[4]arenes towards the formation of dimeric capsules and assemblies using ionic and neutral species as guest molecules and templates. The multitude of different crystal structures obtained during these studies demonstrates the versatile nature of resorcin[4]arenes and pyrogall[4]arenes (2‐hydroxy‐resorcin[4]arenes) as supramolecular hosts in crystal engineering.

Encapsulation of secondary and tertiary ammonium salts by resorcinarenes and pyrogallarenes: the effect of size and charge concentration

“…35 The ability of resorcinarenes to bind both symmetrical and unsymmetrical quaternary ammonium salts is well reported. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Tetramethyl ammonium (TMA) cation is of optimum size and orientation to template dimeric capsular assemblies. 5,8,10,[17][18][19] Complexes of resorcinarenes and diquaternary ammonium [N,N-dialkyl-1,4-diazabicyclo[2.2.2]octane (alkyl 2 -DABCO)] dications show higher binding constant in alcoholic solvents than the quaternary ammonium analogues 14 due to the higher charge concentration of the diquaternary ammonium cations.…”

Recognition of N‐Alkyl and N‐Aryl Acetamides by N‐Alkyl Ammonium Resorcinarene Chlorides

“…[17][18][19] Unfunctionalized resorcinarenes have a pbasic cavity and can bind guests through cation···p, CH···p, and hydrophobic interactions. [1,2,5] In addition, the resorcinarene salts can, by means of the circular hydrogen-bond seam, interact with guests through hydrogen-bond interactions. [17,18] Recently, the resorcinarene salts have been shown to also act as halogen-bond [20] acceptors to give deep-cavity cavitand-like compounds.…”

To catalyze or not to catalyze: elucidation of the subtle differences between the hexameric capsules of pyrogallolarene and resorcinarene

“…2†). Therefore, the formation of smaller (dimeric, or monomeric) pyrogallolarene–cation complexes observed in methanol solution 5 c and in the solid state 5g,8 can be excluded.…”