Solid-state caging of 1,10-phenanthroline π–π stacked dimers by calix[4]arene dihydroxyphosphonic acid

Abstract

The calix[4]arene dihydroxyphosphonic acid-1,10-phenanthroline complex shows caging of the guest molecules as a pi-pi stacked dimer in a cavity formed by intermolecular hydrogen bonds and aromatic walls formed by the calixarene.

Assembly modes in the solid state structure of the complexes of melamine mono-cations with para-calix[4]arene sulfonic acid and calix[4]arene dihydroxyphosphonic acid

“…21 The dimeric calixarene motif forms cages holding p-p stacked dimers for the complex with phenanthroline. 22 In the case of the complex with 2,2 0 -bipyridine, 4,4 0 -bipyridine and 1,2-bis (4-pyridyl)ethane 23 1D ladder structures have been observed. Using melamine as a base and the above two calix [4]arenes as the acid, we present here the solid state structures of their complexes, showing subtle and interesting variations in the assembly mode.…”

Chapter 14. Structural Diversity in Metal Phosphonate Frameworks: Impact on Applications

“…95 It is interesting to note that one of the phosphonate oxygens participates in a Cu-m 2 -O-Cu bridge; however, the Cu-O distances seem to be unaffected. Lastly, there is a ''long'' Cu-O distance (2.284(3) Å ), but this dramatic elongation is due to the Jahn-Teller effect (common in a d 9…”

Structure of the kanamycin–calix[4]arene di-O-phosphonate salt

“…As has been oberved for almost all solid-state structures involving calix [4]arene diphosphonic acid, the classical interdigated dimeric motif is present for the anion. The interdigitation angle is 156.9 which lies in the middle of the range of 153.6(5) found in the complex of calix [4]arene diphosphonic acid with melanine, 21 to 163 in the case of the potassium salt. 23 There is one short interaction (d ¼ 3.383 A ˚) between the two aromatic rings which are included in the cavities of a dimer (Fig.…”

“…15 The known crystal structure of kanamycin shows an elongated motif for the three glycosidic units comprised in the cation. 16 Calix [4]arene diphosphonic acid has been shown to bind as an anion to a number of alkyl 18 and heterocyclic ammonium cations, 19 including the antiseptic chlorhexidine. 20 In all cases where complexation takes place from aqueous solvents the base structural motif is an interdigitated dimer.…”

“…20 In all cases where complexation takes place from aqueous solvents the base structural motif is an interdigitated dimer. The packing motifs observed range from simple bilayer systems in the complex with melanine, 21 through cage structures seen with phenanthroline 22 to assemblies with aqua channels for the complex with the propane diammonium cation. 23 As in all the above cases, there was association between ammonium functions and calix [4]arene diphosphonic acid, despite a relatively low number of structures in the CSD, the extension to drug molecules was of interest and the first class tested were the aminoglycosidic antibiotics, as here crystallisation by complexation with the less polar calix [4]arene diphosphonic acid should aid crystal formation.…”