Synthesis and Structural Analysis of the Polymetallated Alkali Calixarenes [M₄(p‐tert‐butylcalix[4]arene‐4H)(thf)_x]₂⋅n THF (M=Li, K; n=6 or 1; x=4 or 5) and [Li₂(p‐tert‐butylcalix[4]arene‐2H)(H₂O)(μ‐H₂O)(thf)]⋅3 THF

Abstract

To study the structures and reactivities of alkali metallated intermediates of calix[4]arenes, three compounds were isolated: [Li(4)(p-tert-butylcalix[4]arene-4H)(thf)(4)](2).6 THF (1), [Li(2)(p-tert-butylcalix[4]arene-2H)(H(2)O)(mu-H(2)O)(thf)].3 THF (2), and [K(4)(p-tert-butylcalix[4]arene-4H)(thf)(5)](2).THF (3). The structure of 1 is shown to be dependent on the coordinating solvent. Partial hydrolysis of 1 leads to the formation of 2. The potassium compound 3 features a different structure to that of 1, due to a higher coordination number as well as stronger cation-pi-bonding interactions.

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

“…This has first led us to the field of alkali [9][10][11][12] and alkaline earth metal compounds, [13,14] of which a number of new clusters were observed. [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. [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.…”

Mixed Metal Multinuclear Cr(III) Cage Compounds and Coordination Polymers Based on Unsubstituted Phenolate: Design, Synthesis, Mechanism, and Properties

“…36,37,43,44 In this context, we have also used calixarenes, which can be understood as cyclic polyphenols, to obtain lithium polyaryloxides. 22,23,37,40 This straightforward access to mixed metal aryl-and alkoxides inspired us to use this approach, replacing alkaline earth metal halides by chromium dihalides as starting compounds due to their better solubility and in spite of the sensitivity of such compounds to humidity. 45 Very similar to a compound described by us, [Ca(OPh) 8 Li 6 -(THF) 6 ], 42 the literature reports on a Cr(II) compound, namely, [Cr(OPh) 5 Li 3 (THF) 3 ] 2 , A (Figure 1), described by Edema et al 46 We were intrigued by this structure, expecting it to be easily oxidized yielding new Cr(III) species which are otherwise not available by direct synthesis from Cr(III) salts and reactions with phenolates.…”

“…36,37,43,44 In this context, we have also used calixarenes, which can be understood as cyclic polyphenols, to obtain lithium polyaryloxides. 22,23,37,40 This straightforward access to mixed metal aryl-and alkoxides inspired us to use this approach, replacing alkaline earth metal halides by chromium dihalides as starting compounds due to their better solubility and in spite of the sensitivity of such compounds to humidity. …”

Mixed metal multinuclear Cr(III) cage compounds and coordination polymers based on unsubstituted phenolate: design, synthesis, mechanism, and properties

“…36,37,43,44 In this context, we have also used calixarenes, which can be understood as cyclic polyphenols, to obtain lithium polyaryloxides. 22,23,37,40 This straightforward access to mixed metal aryl-and alkoxides inspired us to use this approach, replacing alkaline earth metal halides by chromium dihalides as starting compounds due to their better solubility and in spite of the sensitivity of such compounds to humidity. 45 Very similar to a compound described by us, [Ca(OPh) 8 Li 6 -(THF) 6 ], 42 the literature reports on a Cr(II) compound,…”