Synthesis, Structure and Anion Sensing Properties of a Dicationic Bis(imidazolium)-Based Cyclophane
The preparation and sensing properties of a tetracyclic cyclophane receptor containing two imidazolium rings as anion binding sites and two fluorene rings as fluorescent signaling units, are reported. The receptor behaves as a selective fluorescent chemosensor molecule for inorganic phosphates. H-NMR spectroscopical data clearly indicate the simultaneous occurrence of charge-assisted aromatic and aliphatic C−H noncovalent interactions. PCM/DFT calculations have been carried out to predict the structures of the complexes formed with one and two molecules of PF , HPO and HPO .
2,4,5-Trimethylimidazolium Scaffold for Anion Recognition Receptors Acting Through Charge-Assisted Aliphatic and Aromatic C–H Interactions
A series of two-armed 2,4,5-trimethylimidazolium-based oxoanion receptors, which incorporate two end-capped photoactive anthracene rings, being the central core an aromatic or heteroaromatic ring, has been designed. In the presence of HP2O7(3-), H2PO4(-), and SO4(2-) anions, (1)H- and (31)P NMR spectroscopical data clearly indicate the simultaneous occurrence of several charge-assisted aliphatic and aromatic C-H noncovalent interactions, i.e., significant downfield shifts were observed for the imidazolium C(2)-CH3 protons, the methylene N-CH2 protons, and the inner aromatic proton or the outer heteroaromatic protons. Density functional theory calculations confirm the occurrence of these non…
CCDC 1456591: Experimental Crystal Structure Determination
Related Article: Paula Sabater, Fabiola Zapata, Antonio Caballero, Israel Fernández, Carmen Ramirez de Arellano, and Pedro Molina|2016|J.Org.Chem.|81|3790|doi:10.1021/acs.joc.6b00468
CCDC 1821490: Experimental Crystal Structure Determination
Related Article: Paula Sabater, Faviola Zapata, Pedro Molina, Ibon Alkorta, Jose Elguero, Antonio Caballero, Carmen Ramirez de Arellano|2018|Chem. Sel.|3|3855|doi:10.1002/slct.201800809