Skip to main content Accessibility help
×
Home

Interactions of Actinide Analogues with Naturally Occurring Organic Matter

  • Barbara E. Stout (a1) and Cielito M. Deramos (a1)

Abstract

We have studied the interaction of a low molecular weight alginic acid (ca. 7,000 daltons) with Ca2+, Mg2+, Eu3+ and La3+, using lanthanide luminescence spectroscopy (LLS) and 13C NMR. LLS results imply that nine-coordinate lanthanide ions lose six water molecules upon complexation with alginate, forming inner-sphere alginate complexes. In general, the 13C resonances in the NMR studies decreased in intensity as metal ion concentration increased, but the preference of a cation for repeating mannuronate and guluronate units (MM and GG blocks) varied greatly. The La3+ ion binds preferentially to the GG blocks, though some binding to the MM blocks is evident, while Eu3+ binds equally well to GG and MM blocks. Ca2+ shows a strong preference for the GG blocks only, while Mg2+ shows no evidence of binding to alginate at all. These preferences may be explained in terms of cation size, charge and coordination number. The diequatorial linkage pattern of sequential mannuronate residues leads to a flat ribbon-like structure with shallow cavities for the metal ions while the diaxial linkages of the guluronates allow a deeper, more size-specific cavity. Calcium has the optimum ionic radius for the GG cavities compared to the larger Eu3+ and La3+ ions. The smaller Mg2+ ion does not bind at all over the concentration range studied. This could be due to its large charge density to coordination number ratio that would make dehydration of this ion and subsequent complexation by alginate thermodynamically unfavorable.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Interactions of Actinide Analogues with Naturally Occurring Organic Matter
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Interactions of Actinide Analogues with Naturally Occurring Organic Matter
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Interactions of Actinide Analogues with Naturally Occurring Organic Matter
      Available formats
      ×

Copyright

References

Hide All
1. Choppin, G. R. and Stout, B. E., Sci. of the Total Environment, 83, 203 (1989).
2. Stevenson, F. J., Humus Chemistry. (John Wiley and Sons: New York, 1982).
3. Schweiger, R. G., J. Org. Chem, 27,1789 (1962).
4. Muzzarelli, R.A.A., Natural Chelating Polymers. (Pergammon Press: New York, 1973).
5. Horrocks, W. W. and Sudnick, D R., J. Am Chem. Soc, 101, 334 (1979).
6. Stout, B.E. and DeRamos, C.M., unpublished results.
7. Wang, Z., Zhang, Q., Konna, M., Saito, S., Biopolymers, 33, 703 (1993).
8. Shannon, R. D., Acta Cryst., 32A, 751 (1976).

Interactions of Actinide Analogues with Naturally Occurring Organic Matter

  • Barbara E. Stout (a1) and Cielito M. Deramos (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed