eprintid: 8843 rev_number: 5 userid: 6 dir: disk0/00/00/88/43 datestamp: 2011-11-10 19:56:37 lastmod: 2016-11-15 13:47:57 status_changed: 2011-11-10 19:56:37 type: thesis_degree metadata_visibility: show contact_email: dac11@pitt.edu item_issues_count: 0 eprint_status: archive creators_name: Czegan, Demetra Anne Chengelis creators_email: dac11@pitt.edu creators_id: DAC11 title: NOVEL ANTENNAE FOR THE SENSITIZATION AND PROTECTION OF LANTHANIDE CATIONS EMITTING IN THE VISIBLE AND NEAR-INFRARED ispublished: unpub divisions: sch_as_chemistry full_text_status: public keywords: antenna effect; chrysin; doped semiconductor nanocrystals; doping; flavonoids; galangin; lanthanide properties; lanthanides; morin; quantum dots; quercetin; spectrophotometric titrations; CdSe semiconductor nanocrystals; naringenin; near infrared lanthanides; near infrared luminescence; metal-organic frameworks abstract: Several lanthanide cations are luminescent in the visible and in the near-infrared (NIR) regions, with unique and advantageous luminescence properties compared to organic fluorophores, which make luminescent lanthanide complexes desirable for a range of applications including light amplification, optical telecommunications, biological imaging and bioanalytical techniques. To overcome the limitation of low absorptivity and weak luminescence of free lanthanide cations in solution, lanthanide complexes are formed with chromophoric groups that are capable of absorbing incident light, and transferring the resulting energy to the lanthanide cation thus sensitizing luminescence ("antenna effect"). Additionally, lanthanide cations must be protected from solvent molecules whose vibrational overtones efficiently deactivate lanthanide cation excited states through non-radiative routes. The research work presented here has focused on developing lanthanide species with improved photophysical properties, utilizing a variety of approaches to reach two main goals: providing efficient sensitization of lanthanide cations via the antennae effect and superior protection against non-radiative deactivation. In a relatively traditional coordination chemistry approach, natural product molecules of the flavonoid family were used as antennae for NIR emitting lanthanide cations. Using a nanomaterials approach to achieve improved protection from quenching, visible emitting lanthanide cations were incorporated into CdSe semiconductor crystals, which bring their own electronic properties, including broad absorbance bands with high epsilon values and size dependent band gaps. Thus, the nanocrystals are used to provide protection from quenching as well as sensitize lanthanide cations through the antennae effect. In an alternate nanomaterials approach NIR emitting Yb3+ and Nd3+ were incorporated into NaYF4 inorganic nanoparticle matrices that were coated with organic tropolonate sensitizing groups. The nanoparticle matrix protects the lanthanide cations from non-radiative deactivation while the surface bound chromophores provide antennae effect sensitization. In addition, upconverting NaYF4:Yb,Er nanocrystals were synthesized and their potential to serve as energy acceptors from a naphthalimide based antenna or energy donors to Quantum Dots were investigated. Finally, metal-organic frameworks (MOFs) were explored as method to sensitize NIR and visible emitting lanthanide cations by incorporating the lanthanide cations at metal sites in the MOF structure and/or as occupants of the pores of zinc based MOFs. date: 2009-10-01 date_type: completed institution: University of Pittsburgh refereed: TRUE etdcommittee_type: committee_chair etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_name: Petoud, Stephane etdcommittee_name: Michael, Adrian etdcommittee_name: Waggoner, Alan etdcommittee_name: Saxena, Sunil etdcommittee_email: spetoud@pitt.edu etdcommittee_email: amichael@pitt.edu etdcommittee_email: waggoner@cmu.edu etdcommittee_email: sksaxena@pitt.edu etdcommittee_id: SPETOUD etdcommittee_id: AMICHAEL etdcommittee_id: etdcommittee_id: SKSAXENA etd_defense_date: 2009-07-31 etd_approval_date: 2009-10-01 etd_submission_date: 2005-08-03 etd_access_restriction: 5_year etd_patent_pending: FALSE assigned_doi: doi:10.5195/pitt.etd.2011.8843 thesis_type: dissertation degree: PhD committee: Stephane Petoud (spetoud@pitt.edu) - Committee Chair committee: Adrian Michael (amichael@pitt.edu) - Committee Member committee: Alan Waggoner (waggoner@cmu.edu) - Committee Member committee: Sunil Saxena (sksaxena@pitt.edu) - Committee Member etdurn: etd-08032005-105327 other_id: http://etd.library.pitt.edu/ETD/available/etd-08032005-105327/ other_id: etd-08032005-105327 citation: Czegan, Demetra Anne Chengelis (2009) NOVEL ANTENNAE FOR THE SENSITIZATION AND PROTECTION OF LANTHANIDE CATIONS EMITTING IN THE VISIBLE AND NEAR-INFRARED. Doctoral Dissertation, University of Pittsburgh. (Unpublished) document_url: http://d-scholarship-dev.library.pitt.edu/8843/1/DemetraCzeganPhDThesis.pdf