Recognition of nitrate by the ammonium derivative of a 20-membered dioxadiaza-calix[4]arene analog—solution and solid-state study of the anion binding properties. Issue 8 (25th February 2015)

• Record Type: Journal Article
• Authors: Moreno-Corral, Ramón; Höpfl, Herbert; Yatsimirsky, Anatoly K.; Gálvez-Ruiz, Juan Carlos; Lara, Karen O.
• Is Part Of: Tetrahedron. Volume 71:Issue 8(2015)
• Page Start: 1232
• Page End: 1240
• Publication Date: 2015-02-25
• Subjects: Calixarene analog -- Cyclophane -- Host–guest chemistry -- Anion recognition -- Nitrate receptor -- X-ray structure analysis; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2015.01.005
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A 20-membered dioxadiaza-calix[4]arene analog (1 ) was combined with a series of inorganic acids to explore the anion-inclusion properties of the corresponding ammonium dication [1-H 2 ] 2+ . The neutral calix[4]arene analog 1 and six salts of the receptor in the mono- or diprotonated form, [1-H 2 ]Cl2 (2 ), [1-H 2 ]Br2 (3 ), [1-H 2 ][MeOSO3 ]2 (4 ), [1-H 2 ][NO3 ]2 (5 ), [1-H 2 ][ClO4 ]2 (6 ), and [1-H ][ClO4 ] (6b ), were structurally characterized by single-crystal X-ray diffraction analysis, which enabled a detailed comparative analysis of the non-covalent interactions. The structural comparison showed that the different anions induce conformational changes of the macrocyclic structure, but only NO 3 − gave a true inclusion complex. Additionally, the tetramethylammonium derivative of1, [1-Me 4 ]I2 (7 ), was prepared and structurally characterized. 1 H NMR titration studies of [1-H 2 ] 2+ in an aqueous–polar solvent mixture (H2 O/MeOH, 9:1 v/v, pH 5.5) with a series of organic and inorganic anions gave association constants varying from 1.4 to 84.6 M −1 . Graphical abstract: