Analysis of molecular square size and purity via pulsed-field gradient NMR spectroscopy

Inorganic Chemistry

Volumn 41, Issue 24, 2002, Pages 6172-6174

  Otto, William H ^a,b   Keefe, Melinda H ^a,b   Splan, Kathryn E ^a,b   Hupp, Joseph T ^a,b   Larive, Cynthia K ^a,b  

^a UNIVERSITY OF KANSAS   (United States)

^b NORTHWESTERN UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

METAL COMPLEX;

ARTICLE; CHEMICAL ANALYSIS; CHEMICAL STRUCTURE; COMPLEX FORMATION; DIFFUSION COEFFICIENT; HYDRODYNAMICS; MACROMOLECULE; MASS SPECTROMETRY; MOLECULAR WEIGHT; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; SOLUBILITY;

EID: 0037010976     PISSN: 00201669     EISSN: None     Source Type: Journal    
DOI: 10.1021/ic020334k     Document Type: Article

References (23)

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6. (b) Ruegger, H.; Pregosin, P. S. Helv. Chim. Acta 2001, 84, 2833 and references therein.
7. Terrill, R. H.; Postlethwaite, T. A.; Chen, C. H.; Poon, C. D.; Terzis, A.; Chen, A. D.; Hutchison, J. E.; Clark, M. R.; Wignall, G.; Londono, J. D.; Superfine, R.; Falvo, M.; Johnson, C. S.; Samulski, E. T.; Murray, R. W. J. Am. Chem. Soc. 1995, 117, 12537.
8. Hodge, P.; Monvisade, P.; Morris, G. A.; Preece, I. Chem. Commun. 2001, 239-240.
9. Burini, A.; Fackler, J. P.; Gallassi, R.; Macchioni, A.; Omary, M. A.; Rawashdeh-Omary, M. A.; Pietroni, B. R.; Sabatani, S.; Zuccaccia, C. J. Am. Chem. Soc. 2002, 124, 4570.
10. Timmerman, P.; Weidman, J.-L.; Jolliffe, J.-L.; Prins, L. J.; Reinhoudt, D. N.; Shinkai, S.; Frish, L.; Cohen, Y. J. Chem. Soc., Perkin Trans. 2 2000, 2077-2089 and references therein.
11. Olenyuk, B.; Levin, M. D.; Whiteford, J. A.; Shield, J. E.; Stang. P. J. J. Am. Chem. Soc. 1999, 121, 10434-10435.
12. (a) Giordano, P. J.; Wrighton, M. S. J. Am. Chem. Soc. 1979, 101, 2888.
13. (b) Slone, R. V.; Hupp, J. T.; Stern, C. L.; Albrecht-Schmitt, T. E. Inorg. Chem. 1996, 35, 4096.
14. (c) Forsyth, T. P.; Nurco, D. J.; Pandey, R. K.; Smith, K. M. Tetrahedron Lett. 1995, 36, 9093.
15. (d) Slone, R. V.; Hupp, J. T. Inorg. Chem. 1997, 36, 5422.
16. (e) LeCours, S. M.; Dimagno, S. G.; Therien, M. J. J. Am. Chem. Soc. 1996, 118, 11854.
17. All compounds were prepared via literature methods or purchased from Aldrich. Comer 4 was synthesized according to ref 9a, square 5 was synthesized according to the procedure in ref 9d for a closely related square, and ligand 5 was synthesized according to the procedure in ref 9e for closely related porphyrins. Satisfactory elemental analyses were obtained.
18. 5 was added to solutions of the ligand and square of 4 to solubilize them fully. The reported D values are averages of 3 measurements on the same sample. The reported error is the larger of either the exponential fitting error or the standard deviation of the 3 trials.
19. (a) Cussler, E. L. Diffusion; Mass Transfer in Fluid Systems; Cambridge University Press: Cambridge, 1984.
20. (b) Hansen, J. P.; McDonald, I. R. Theory of Simple Fluids; Academic Press: London, 1976.
21. The fit is insufficiently precise to distinguish a square from a triangle. Studies of rigid multidentate guest binding, however, support the square geometry, as do molecular sieving studies (probe-molecule size cutoff studies) of thin films of 5.
22. Fan, J.; Whiteford, J. A.; Olenyuk, B.; Levin, M. D.; Stang, P. J.; Fleischer, E. B. J. Am. Chem. Soc. 1999, 121, 2741.
23. In principle, plots of In intensity versus gradient amplitude squared could also be used to assess the presence of contaminants having resonances identical to those of the parent compound. A straight-line relationship indicates a single unique diffusion coefficient, whereas a nonlinear curve is indicative of multiple species possessing different diffusion coefficients, In practice, experiments using intentionally prepared mixtures of square 2 and either ligand 2 or comer 2, and integrating over the region containing the overlapped resonances, show that curvature is readily evident only when the "contaminant" comprises a significant percentage (approximately 10-25%) of the sample.