We have a general interest in exploring the redox chemistry of lanthanide cations, especially the oxidation chemistry of cerium. Recently, we have been developing the chemistry of redox active hydroxylamine ligands to study unique aspects of metal–ligand non-innocence in the 4f block.1 These hydroxylamine ligands stabilized a redox active cerium(IV) cation to an unprecedented degree with, for example, a Ce(III/IV) redox couple at –1.95 V versus Fc/Fc+. Moreover, we devoted efforts to understanding the relationship between crystal field strength and cerium redox chemistry and explored whether this relationship could be modeled computationally. In this context, we have successfully developed DFT methods for predicting the redox potentials of cerium complexes with varied ligands and solvent environments.2

        

  1. (a) Bogart, J. A.; Lewis, A. J.; Medling, S. A.; Piro, N. A.; Carroll, P. J.; Booth, C. H. Schelter, E. J. Inorg. Chem. 2013, 52, 11600–11607. (b) Kim, J. E.; Carroll, P. J.; Schelter, E. J. Chem. Comm. 2015, 51, 15047–15050. (c) Bogart, J. A.; Lippincott, C. A.; Carroll, P. J.; Booth, C. H.; Schelter, E. J. Chem. Eur. J. 2015, 21, 17850–17859.
  2. (a) Bogart, J. A.; Lewis, A. J.; Boreen, M. A.; Lee, H. B.; Medling, S. A.; Carroll, P. J.; Booth, C. H.; Schelter, E. J. Inorg. Chem. 2015, 54, 2830–2837. (b) Levin, J. R.; Dorfner, W. L.; Dai, A. X.; Carroll, P. J.; Schelter, E. J. Inorg. Chem. 2016, 55, 12651–12659.

We are also working to prepare f-element compounds and molecular materials whose valence can only precisely be described as intermediate between canonical oxidation states and exploring their unusual spectroscopic and magnetic behaviors using magnetic susceptibility and the X-ray absorption measurements.

Unique luminescent characteristics enable lanthanide ions to be applied in solid-state lasers, phosphors and fluorescent lamps. Besides those optical applications, we are currently developing new areas for the application of brightly luminescent cerium compounds: their use as photo-catalysts for organic molecule transformations.3 We expect that our findings will expand the library of photo-catalysts from transition metal photosensitizers to lanthanide ones.      

   

  1. (a) Yin, H.; Carroll, P. J.; Anna, J. M.; Schelter, E. J.J. Am. Chem. Soc.  2015, 137, 9234–9237. (b) Yin, H.; Carroll, P. J.; Manor, B. C.; Anna, J. M.; Schelter, E. J. J. Am. Chem. Soc. 2016, 5984–5993. (c) Yin, H.; Jin, Y.; Hertzog, J. E.; Mullane, K. C.; Carroll, P. J.; Manor, B. C.; Anna, J. M.; Schelter, E. J. J. Am. Chem. Soc. 2016, 138, 16266–16273.