Ana de Bettencourt-Dias

Associate Professor

Inorganic and Materials Chemistry

Licenciatura (1993), University of Lisbon, Portugal;
Dr. rer. nat. (1997), magna cum laude, University of Cologne, Germany (Thomas Kruck); Gulbenkian Postdoctoral Fellow (1998-2001), University of California, Davis (Alan L. Balch).

E-mail: abd [at] unr.edu
Phone: 775-682-8421
FAX: 775-784-6804
Office: CB 226

Ana de Bettencourt-Dias

Research Interests

We are interested in the luminescence of lanthanide ions and how to utilize this property to develop new emitting materials for display applications.

The emission spectra of lanthanide ions arise from f-f transitions. Since the 4f electrons are shielded from the ligand environment by the filled 5s and 5p orbitals, the 4f orbitals have essentially core character and are not influenced by the metal ion's coordination environment. Thus, the f-f transitions are extremely narrow, leading to high emission color purity, and each ion has its own characteristic emission. However, the transitions are forbidden by selection rules and thus population of the lanthanide ion emissive state is achieved through sensitization. In this process the metal ion's luminescence is accomplished through excitation of a coordinated ligand and subsequent energy transfer from a triplet state of the ligand to the metal ion by a dipole-dipole exchange mechanism.

One area of our research involves the design and synthesis of ligands that will be good sensitizers. We routinely synthesize and characterize new organic molecules, which will be utilized as ligands/sensitizers for luminescent metal complexes. These molecules are studied with a variety of techniques and we utilize X-ray single crystal and powder diffraction, vibrational, absorption and emission spectroscopy as standard characterization tools. The ligands are further extensively characterized by electrochemistry. By utilizing this technique, we study electropolymerization as a mean to forming polymer films that can potentially be functionalized with lanthanide ions.

Another area of research involves the synthesis of metal complexes of the new ligands synthesized by our group. In addition to the standard characterization techniques, we extensively utilize emission spectroscopy to qualitatively and quantitatively characterize the luminescence properties of the new metal complexes and their solutions. Knowledge of these properties allows us to improve on the designed ligands and metal complexes to obtain highly efficient emitters.

Students in our group learn the principles of organic synthesis and molecular design, as well as the synthesis of metal complexes and isolation of X-ray quality single crystals. Further, they have the opportunity to learn X-ray single crystal diffraction and electrochemistry as well as vibrational, absorption, emission and NMR spectroscopy.

Selected Publications

“Thiophene-derivatized Pybox and its highly luminescent lanthanide ion complexes,” de Bettencourt-Dias, A.; Viswanathan, S.; Rollett, A. J. Am. Chem. Soc. 2007, asap.

“Lanthanide-based emitting materials in light-emitting diodes,” de Bettencourt-Dias, A. Dalton Trans. 2007, 2229-2241.

“Exploring lanthanide luminsecence in metal-organic frameworks: Synthesis, structure, and guest sensitized luminescence of a mixed europium/terbium-adipate framework and a terbium-adipate framework,” de Lill, D.T.; de Bettencourt-Dias, A.; Cahill, C.L. Inorg. Chem. 2007, 46, 3960-3965.

“Small molecule luminescent lanthanide ion complexes - Photophysical characterization and recent developments,” de Bettencourt-Dias, A. Curr. Org. Chem. 2007, 11, 1460-1480.

“Phenylthiophene-dipicolinic acid-based with strong solution blue and solid state green emission,” de Bettencourt-Dias, A.; Poloukhtine, A. J. Phys. Chem. B 2006, 110, 25638-25645.

“Eu(III) and Tb(III) luminescence sensitized by thiophenyl-derivatized nitrobenzoato antennas,” Viswanathan, S.; de Bettencourt-Dias, A. Inorg. Chem. 2006, 45, 10138-10146.

“Nitro-functionalization and quantum yield of Eu(III) and Tb(III) benzoic acid complexes,” de Bettencourt-Dias, A.; Viswanathan, S. Dalton Trans. 2006, 4093-4103.

“2-Chloro-5-nitrobenzoato complexes of Eu(III) and Tb(III) - A 1 D coordination polymer and enhanced solution luminescence,” Viswanathan, S.; de Bettencourt-Dias, A. Inorg. Chem. Comm. 2006, 9, 444-448.

“Intermolecular forces and functional group effects in the packing structure of thiophene derivatives,” de Bettencourt-Dias, A.; Viswanathan, S.; Ruddy, K. Cryst. Growth Des. 2005, 5, 1477-1484.

“New isophthalato-based 2D coordination polymers of Eu(III), Gd(III), and Tb(III) - Enhancement of the terbium-centered luminescence through thiophene derivatization,” de Bettencourt-Dias, A. Inorg. Chem. 2005, 44, 2734-2741.

“Luminescent nitrobenzoato complexes of Ln3+: First examples of sensitization of green and red emission,” de Bettencourt-Dias, A.; Viswanathan, S. Chem. Commun. 2004, 8, 1024-1025.