Unique Hydrogen‐Bonded Complex of Hydronium and Hydroxide Ions

Abstract

H3 O(+) and OH(-) , formed by the self-ionization of two coordinating water molecules during the crystal growing of a host molecule [1,3,5-tris(hydroxymethyl)2,4,6-triethylbenzene (1)], could be effectively stabilized by hydrogen-bonding interactions with the preorganized hydroxy groups of three molecules of 1. The binding motifs observed in the complex (1)3 ⋅H3 O(+) ⋅HO(-) show remarkable similarity to those postulated for the hydrated hydronium and hydroxide ion complexes, which play important roles in various chemical, biological, and atmospheric processes, but their molecular structures are still not fully understood and remain a subject of intensive research.

Synthesis and crystal structure of 1,3-bis{[N,N-bis(2-hydroxyethyl)amino]methyl}-5-{[(4,6-dimethylpyridin-2-yl)amino]methyl}-2,4,6-triethylbenzene

“…The 1,3,5-trisubstituted 2,4,6-trialkylbenzene scaffold has shown to be valuable for the construction of various artificial receptors (Hennrich & Anslyn, 2002). In the course of our research work, we have successfully used this molecular scaffold in the design of acyclic and macrocyclic receptors for neutral (Mazik, 2009(Mazik, , 2012Amrhein et al, 2016;Koch et al, 2016;Amrhein & Mazik, 2021;Ko ¨hler et al, 2020Ko ¨hler et al, , 2021 and ionic substrates (Geffert et al, 2013;Stapf et al, 2015;Schulze et al, 2018). Our studies on the molecular recognition of carbohydrates have shown that the participation of different types of recognition groups in the complexation of the substrate favourably influences the binding process (Stapf et al, 2020a,b;Kaiser et al, 2019).…”

Crystal structure of 9,9-diethyl-9H-fluorene-2,4,7-tricarbaldehyde

“…Compounds featuring a fluorene moiety have been recognized as useful for a broad spectrum of applications, which range from agents for cell imaging, solar cells, organic light-emitting diodes to lasers. Furthermore, fluorene derivatives have the potential to act as artificial receptors for different ionic and neutral substrates in analogy to the known receptors possessing a benzene or biphenyl core, which, for example, are able to complex ammonium ions (Koch et al, 2015;Schulze et al, 2018;Chin et al, 2002;Arunachalam et al, 2010), ion pairs (Stapf et al, 2015) or carbohydrates (Stapf et al, 2020;Kö hler et al, 2020Kö hler et al, , 2021Kaiser et al, 2019;Lippe & Mazik, 2013Amrhein et al, 2016;Amrhein & Mazik, 2021). As a result of the manifold application possibilities of fluorenes, the syntheses of new representatives of this class of compounds are the subject of intensive research (Seidel et al, 2019(Seidel et al, , 2021Seidel & Mazik, 2020;Sicard et al, 2018).…”

Crystal structures of 2-[3,5-bis(bromomethyl)-2,4,6-triethylbenzyl]isoindoline-1,3-dione and 2-{5-(bromomethyl)-3-[(1,3-dioxoisoindolin-2-yl)methyl]-2,4,6-triethylbenzyl}isoindoline-1,3-dione

“…Compounds consisting of a 1,3,5-trisubstituted 2,4,6-trialkylbenzene scaffold have been recognized to possess the ability to act as artificial receptors for various neutral and ionic substrates, such as carbohydrates (Mazik, 2009(Mazik, , 2012, ion pairs (for example, hydronium/hydroxide ions; Stapf et al, 2015) and ammonium ions (Chin et al, 2002;Jonah et al, 2017;Schulze et al, 2018). In the case of carbohydrate-binding agents (artificial carbohydrate receptors), both acyclic (Kaiser et al 2019;Stapf et al, 2020aStapf et al, , 2020bKö hler et al, 2020) and macrocyclic compounds (Lippe & Mazik, 2013, 2015Amrhein et al, 2016;Amrhein & Mazik, 2021) have been developed.…”