Transport properties of solid state crown ether channel systems

Abstract

Abstract]I 3 1 were shown to possess ideally stacked crown ether molecules which form channels running in one direction through the solid state structure. By immersion of single crystals of 1 into NaOH, ion exchange takes place to yield the compound [(Na)3(DB18C6)(m 2 -H 2 O) 2/2 ][(Na)3(DB18C6)(m 2 -OH) 2/2 ]I 3 2, with slightly but significantly different cell parameters. Both compounds were tested for transport properties through these channels by using two different devices, one for water transport, the other for NaOH transport, through single crystals of 1 and 2, respectively. The results indicate that transport can take place via a hopping mechanism.

Coordination polymer networks with s-block metal ions

“…One of these is [Na ⊂ (DB18C6)(-OH)][Na ⊂ (DB18C6)(-H 2 O)]I 3 (Fig. 2) [2]. These systems do show transport properties for ions as well as water molecules [2], and could therefore be interesting for solid-state batteries.…”

“…Their exact solid-state structure is not well known, but some studies on lithium, sodium and potassium reveal the coordination of the PEO ligand to the metal ions. Almost independently from the anions, the polyether oxygen atoms wrap around the [2]. alkali cations to form single or double helical structures with the metal ions in the center of a channel-like feature [4].…”

From Alkaline Earth Ion Aggregates via Transition Metal Coordination Polymer Networks towards Heterometallic Single Source Precursors for Oxidic Materials

“…[15][16][17][18][19][20][21][22][23] Being hard metal ions, mainly O-donor ligands were chosen for the coordination to these group 1 and 2 ions. Among these ligands are charged monodentate ligands OR, R = H, alkyl, aryl, [22,23] as well as the neutral polyether ligands such as oligo dimethyl ethers, [24][25][26][27][28][29][30][31][32] crown ethers [33,34] or calixarene ligands. [9][10][11][12] While studying these compounds, some of them exhibited unforeseen structures and properties, such as the ion-conductivity observed in one-dimensionally stacked crown ethers or calixarenes.…”

“…[9][10][11][12] While studying these compounds, some of them exhibited unforeseen structures and properties, such as the ion-conductivity observed in one-dimensionally stacked crown ethers or calixarenes. [10,34] Especially the mixed metal cage compounds containing alkali and alkaline earth metal ions, like the [CaLi 6 (OPh) 8 (thf) 6 ] of Fig. 1, are interesting also for catalysis of e.g.…”

Polymorph of Dibenzo‐24‐Crown‐8 and its Mercury Complex

“…Some of our recent research deals also with the use of crown ethers as scaffolds for channel systems. [14][15][16][17][18][19] The dibenzo-crown ethers seem to be stiffer than the simple crown ethers and show fewer conformations. The larger these dibenzo-crowns, the more flexible they become.…”