Tuning receptors for the encapsulation of beryllium²⁺

Abstract

A method for evaluating second sphere H-bonding interactions as a means to tune specific characteristics in coordinating ligands has been used to evaluate the binding strength of a series of beryllium complexes.

The Design of Tetradentate Ligands for Beryllium Encapsulation

“…In contrast, ligands L16L18 and L20 which contain potential hydrogen bonding groups situated within proximity of an intrahard oxygen atom were found to be pre-organized towards the resulting complexation geometry due to the additional stabilizing hydrogen bond(s). 19 The optimized structures showed all ligands coordinated to Be 2+ in a tetradentate fashion, with ligands of type L16L19 forming the cationic complexes [BeLn(x) -H ] + (where x = (a)(e)) and ligand L20 forming the neutral complex BeL20(x) -2H . The highest binding energy occurred with the complexation of ligand L18(b) to the Be 2+ cation.…”

“…18 An initial computational investigation on a series of tetradentate receptors designed to have a selective, compact beryllium binding pocket ( Figure 5) was performed. 19 Ligands L16L18 and L20 provided an N 3 O donor set while ligand L19 presented an N 4 donor set. In ligands L16, L17, L18 and L20 the R groups with amine (b) or (c), amide (d), or urea (e) functionalities had the ability to form a hydrogen bond to the hard oxygen donor.…”

“…However, the greatest enhancement of stabilization energy was seen in the L16 complex series when a comparison of the energies was made between the buttressed complex compared to their non-buttressed counterparts, particularly with the introduction of a methylamine H-bond donating group. 19 The second-sphere intramolecular hydrogen bonding interactions of the methylamine-containing complex [BeL16(c) -H ] + are illustrated in Figure 6.…”

Organomagnesium Crown Ethers and Their Binding Affinities with Li+, Na+, K+, Be2+, Mg2+, and Ca2+ Ions – A Theoretical Study

“…[25] Thus, designing new ligands, which could effectively bind one ion over the other is a key problem to address. Though toxic, beryllium and its alloys are indispensable for the aeronautic and space industry [26,27] due to their comparable mechanical properties to steel but non-magnetic and nonsparking. However, one of the major safety issues in using beryllium and its compounds is that they can cause the development of chronic beryllium disease.…”

Organomagnesium Crown Ethers and Their Binding Affinities with Li+, Na+, K+, Be2+, Mg2+, and Ca2+ Ions - a Theoretical Study

“…[14][15][16][17][18] Though toxic, beryllium and its alloys are indispensable for the aeronautic and space industry. 19,20 This is due to their comparable mechanical properties to steel but at the same time non-magnetic and non-sparking. However, one of the major safety issues in using beryllium and its compounds is that it can cause the development of chronic beryllium disease.…”