Synthesis and recognition properties of calix[4]arene semitubes as ditopic hosts for N-alkylpyridinium ion pairs. Issue 26 (10th May 2016)

• Record Type: Journal Article
• Authors: Vita, Francesco; Vorti, Michela; Orlandini, Guido; Zanichelli, Valeria; Massera, Chiara; Ugozzoli, Franco; Arduini, Arturo; Secchi, Andrea
• Is Part Of: CrystEngComm. Volume 18:Issue 26(2016)
• Page Start: 5017
• Page End: 5027
• Publication Date: 2016-05-10
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c6ce00268d
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Three novel calix[4]arene semitubes having two alkyl bridging spacers of different lengths were synthesized and used as homoditopic hosts for small neutral acidic molecules and N -alkylpyridinium salts. Abstract : A series of calix[4]arene semitubes (4a–c ) having alkyl bridging spacers of different lengths and flexibilities on their lower rim was synthesised and characterised in solution and in the solid state by 1 H NMR spectroscopy and X-ray crystallography. The binding properties of these novel ditopic hosts toward a series of N -alkylpyridinium ion pairs were investigated in low polar media by 1 H NMR and UV-vis spectroscopy and compared with those of the corresponding calix[4]arene monotopic host5 . These studies showed that in low polar solvents, the calix[4]arene semitubes behave as homoditopic hosts giving rise with N -alkylpyridinium ion pairs to supramolecular adducts of 1 : 2 host–guest stoichiometry.