Herein we report on the self-assembly, in a low polarity solvent, of a pseudorotaxane species comprising binaphthyl-26- crown-8 (BN26C8) as the macrocyclic host and anthracenylbenzylammonium as the threadlike positively charged guest (ABH+). Absorption and luminescence data reveal a very efficient energy transfer process occurring from the binaphthyl to the anthracene singlet excited states. The self-assembly is highly dependent on the nature of the counteranion confirming the crucial role played by it in the competition between the self-assembly process and the formation of ion pairs (ABH+X–). This behavior can be readily evidenced in dilute solutions from the analysis of the luminescence properties of the system. The complexation of chloride, sulfate and hexa- Introduction Pseudorotaxanes are host–guest systems composed minimally of a threadlike molecule surrounded by a macrocycle.[ 1] These supermolecules have been attracting considerable attention,[2] not only for their structural features, but also because of the variety of properties and functions that can be engineered within them. For example, pseudorotaxane structures constitute a convenient basis for the design and construction of simple prototypes of artificial nanoscale devices and machines.[3–12] It has long been known[13] that crown ethers give adducts with RNH3 + ammonium ions, stabilized by [N+–H···O] hydrogen bonds.[14] More recently it has been shown[15] that when the crown ether ring is large enough, suitably chosen dialkylammonium ions (R2NH2 +) can thread through the macrocycle to give pseudorotaxane species in solution by virtue of strong [N+–H···O] and [C–H···O] hydrogen-bonding interactions. Upon deprotonation of the ammonium ion [a] Dipartimento di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, 40126 Bologna, Italy [b] Present address: Instituto de Ciencia Molecular, Universidad de Valencia, Dr. Moliner 20, 46100 Burjassot, Spain [c] Dipartimento di Chimica and IMC-CNR, Università La Sapienza di Roma, Box 34 Roma 62, piazzale A. Moro 5, 00185 Roma, Italy E-mail: Antonella.dallacort@uniroma1.it [d] Université de Genève, Département de Chimie Organique, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland Eur. J. Org. Chem. 2006, 105–112 © 2006 Wiley-VCH Verlag GmbH & Co. KgaA, Weinheim 105 fluorophosphate salts of ABH+ by racemic BN26C8 as well as the complexation of ABH+ salts of the chiral anion tris[tetrachlorobenzenediolato] phosphate(V) (TRISPHAT–) by (+) BN26C8 are described. The efficiency in complexation follows the trend PF6 – TRISPHAT– Cl–, SO4 2–. The use of the chiral anion TRISPHAT allowed us to investigate the possibility of inducing stereoselective control on the formation of the interpenetrating assembly. Preliminary 1H NMR spectroscopic evidence supports the fact that the chiral anion is paired to the supramolecular complex and that its configuration influences the recognition process.

Ion-pairing effects in the self-assembly of a fluorescent pseudorotaxane / M., CLEMENTE LEON; Pasquini, Chiara; V., HEBBE VITON; J., Lacour; DALLA CORT, Antonella; A., Credi. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - STAMPA. - 1:(2006), pp. 105-112. [10.1002/ejoc.200500479]

Ion-pairing effects in the self-assembly of a fluorescent pseudorotaxane

PASQUINI, CHIARA;DALLA CORT, Antonella;
2006

Abstract

Herein we report on the self-assembly, in a low polarity solvent, of a pseudorotaxane species comprising binaphthyl-26- crown-8 (BN26C8) as the macrocyclic host and anthracenylbenzylammonium as the threadlike positively charged guest (ABH+). Absorption and luminescence data reveal a very efficient energy transfer process occurring from the binaphthyl to the anthracene singlet excited states. The self-assembly is highly dependent on the nature of the counteranion confirming the crucial role played by it in the competition between the self-assembly process and the formation of ion pairs (ABH+X–). This behavior can be readily evidenced in dilute solutions from the analysis of the luminescence properties of the system. The complexation of chloride, sulfate and hexa- Introduction Pseudorotaxanes are host–guest systems composed minimally of a threadlike molecule surrounded by a macrocycle.[ 1] These supermolecules have been attracting considerable attention,[2] not only for their structural features, but also because of the variety of properties and functions that can be engineered within them. For example, pseudorotaxane structures constitute a convenient basis for the design and construction of simple prototypes of artificial nanoscale devices and machines.[3–12] It has long been known[13] that crown ethers give adducts with RNH3 + ammonium ions, stabilized by [N+–H···O] hydrogen bonds.[14] More recently it has been shown[15] that when the crown ether ring is large enough, suitably chosen dialkylammonium ions (R2NH2 +) can thread through the macrocycle to give pseudorotaxane species in solution by virtue of strong [N+–H···O] and [C–H···O] hydrogen-bonding interactions. Upon deprotonation of the ammonium ion [a] Dipartimento di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, 40126 Bologna, Italy [b] Present address: Instituto de Ciencia Molecular, Universidad de Valencia, Dr. Moliner 20, 46100 Burjassot, Spain [c] Dipartimento di Chimica and IMC-CNR, Università La Sapienza di Roma, Box 34 Roma 62, piazzale A. Moro 5, 00185 Roma, Italy E-mail: Antonella.dallacort@uniroma1.it [d] Université de Genève, Département de Chimie Organique, Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland Eur. J. Org. Chem. 2006, 105–112 © 2006 Wiley-VCH Verlag GmbH & Co. KgaA, Weinheim 105 fluorophosphate salts of ABH+ by racemic BN26C8 as well as the complexation of ABH+ salts of the chiral anion tris[tetrachlorobenzenediolato] phosphate(V) (TRISPHAT–) by (+) BN26C8 are described. The efficiency in complexation follows the trend PF6 – TRISPHAT– Cl–, SO4 2–. The use of the chiral anion TRISPHAT allowed us to investigate the possibility of inducing stereoselective control on the formation of the interpenetrating assembly. Preliminary 1H NMR spectroscopic evidence supports the fact that the chiral anion is paired to the supramolecular complex and that its configuration influences the recognition process.
2006
01 Pubblicazione su rivista::01a Articolo in rivista
Ion-pairing effects in the self-assembly of a fluorescent pseudorotaxane / M., CLEMENTE LEON; Pasquini, Chiara; V., HEBBE VITON; J., Lacour; DALLA CORT, Antonella; A., Credi. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - STAMPA. - 1:(2006), pp. 105-112. [10.1002/ejoc.200500479]
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/363781
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 41
  • ???jsp.display-item.citation.isi??? 37
social impact