skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: α, α', α", α'"- meso-tetrahexyltetramethyl-calix[4]pyrrole: An easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents

Abstract

α, α', α", α'"- meso-Tetrahexyltetramethyl-calix[4]pyrrole is easily obtained as a single diastereomer in a one-pot reaction. It exhibits enhanced solubility in organic solvents, including aliphatic solvents, relative to its parent meso-octamethylcalix[4]pyrrole (1). Somewhat surprisingly, the tetrahexyl derivative 2 complexes with tributylmethylammonium chloride in chloroform more strongly than does 1 as shown by NMR titrations. However, 1 and 2 exhibit comparable complexation strength in extraction experiments, the difference between the NMR and extraction results being attributed to the effect of organic-phase water in the extraction systems. Mass-action analysis indicates the formation of the predominant complex TBMA +(1 or 2)Cl in both NMR and extraction systems, and equilibrium constants are reported. x-Ray crystal structures were obtained for the free ligand 2 and its complex with tetramethylammonium chloride. In addition, the free ligand crystallises in the 1,3-alt conformation with equatorial hexyl arms. In the chloride complex with 2 in its cone conformation, the hexyl arms adopt an axial orientation, enveloping the anion. DFT calculations show this binding conformation to be the most stable, mostly owing to destabilising steric interactions involving the pyrrole C–H and alkyl C–H groups positioned equatorially.

Authors:
 [1];  [2];  [2];  [3];  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Texas, Austin, TX (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1236597
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Supramolecular Chemistry
Additional Journal Information:
Journal Volume: 28; Journal Issue: 1-2; Journal ID: ISSN 1061-0278
Publisher:
Taylor & Francis
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; pyrrole; solubility; anion binding; chloride; extraction

Citation Formats

Williams, Neil J., Bryantsev, Vyacheslav S., Custelcean, Radu, Seipp, Charles A., and Moyer, Bruce A. α, α', α", α'"-meso-tetrahexyltetramethyl-calix[4]pyrrole: An easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents. United States: N. p., 2016. Web. doi:10.1080/10610278.2015.1120873.
Williams, Neil J., Bryantsev, Vyacheslav S., Custelcean, Radu, Seipp, Charles A., & Moyer, Bruce A. α, α', α", α'"-meso-tetrahexyltetramethyl-calix[4]pyrrole: An easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents. United States. doi:10.1080/10610278.2015.1120873.
Williams, Neil J., Bryantsev, Vyacheslav S., Custelcean, Radu, Seipp, Charles A., and Moyer, Bruce A. Fri . "α, α', α", α'"-meso-tetrahexyltetramethyl-calix[4]pyrrole: An easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents". United States. doi:10.1080/10610278.2015.1120873. https://www.osti.gov/servlets/purl/1236597.
@article{osti_1236597,
title = {α, α', α", α'"-meso-tetrahexyltetramethyl-calix[4]pyrrole: An easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents},
author = {Williams, Neil J. and Bryantsev, Vyacheslav S. and Custelcean, Radu and Seipp, Charles A. and Moyer, Bruce A.},
abstractNote = {α, α', α", α'"-meso-Tetrahexyltetramethyl-calix[4]pyrrole is easily obtained as a single diastereomer in a one-pot reaction. It exhibits enhanced solubility in organic solvents, including aliphatic solvents, relative to its parent meso-octamethylcalix[4]pyrrole (1). Somewhat surprisingly, the tetrahexyl derivative 2 complexes with tributylmethylammonium chloride in chloroform more strongly than does 1 as shown by NMR titrations. However, 1 and 2 exhibit comparable complexation strength in extraction experiments, the difference between the NMR and extraction results being attributed to the effect of organic-phase water in the extraction systems. Mass-action analysis indicates the formation of the predominant complex TBMA+(1 or 2)Cl– in both NMR and extraction systems, and equilibrium constants are reported. x-Ray crystal structures were obtained for the free ligand 2 and its complex with tetramethylammonium chloride. In addition, the free ligand crystallises in the 1,3-alt conformation with equatorial hexyl arms. In the chloride complex with 2 in its cone conformation, the hexyl arms adopt an axial orientation, enveloping the anion. DFT calculations show this binding conformation to be the most stable, mostly owing to destabilising steric interactions involving the pyrrole C–H and alkyl C–H groups positioned equatorially.},
doi = {10.1080/10610278.2015.1120873},
journal = {Supramolecular Chemistry},
number = 1-2,
volume = 28,
place = {United States},
year = {Fri Jan 29 00:00:00 EST 2016},
month = {Fri Jan 29 00:00:00 EST 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Density‐functional thermochemistry. III. The role of exact exchange
journal, April 1993

  • Becke, Axel D.
  • The Journal of Chemical Physics, Vol. 98, Issue 7, p. 5648-5652
  • DOI: 10.1063/1.464913

Universal Solvation Model Based on Solute Electron Density and on a Continuum Model of the Solvent Defined by the Bulk Dielectric Constant and Atomic Surface Tensions
journal, May 2009

  • Marenich, Aleksandr V.; Cramer, Christopher J.; Truhlar, Donald G.
  • The Journal of Physical Chemistry B, Vol. 113, Issue 18, p. 6378-6396
  • DOI: 10.1021/jp810292n

Enhanced liquid–liquid anion exchange using macrocyclic anion receptors: effect of receptor structure on sulphate–nitrate exchange selectivity
journal, August 2010

  • Moyer, Bruce A.; Sloop, Frederick V.; Fowler, Christopher J.
  • Supramolecular Chemistry, Vol. 22, Issue 11-12, p. 653-671
  • DOI: 10.1080/10610271003763263