De Lill, Daniel T.

Metal-organic frameworks (MOFs), are a unique
class of materials in which metal clusters are linked
together by organic moieties forming porous 1-D, 2-D,
and 3-D structures. MOFs have many applications
resulting from not only the overall structure, but also
the metal center, organic “linker”, or a combination
thereof. The high surface areas and porosity of these
materials have found use in heterogeneous catalysis,
display technologies, semiconducting materials,
and biomedicine. These materials are also currently
being developed as a new sensor technology for
detection of potentially harmful chemicals. Nitroaromatics
are key components in the fabrication of
explosives, however, current detection methods are
time consuming and expensive. Considering this, our
interest lies in synthesizing MOFs that can be used
as a sensor for nitroaromatic compounds. To this
end, our lab has developed a new Er(III) MOF based
on the linker 2-2’-bithiophene-5,5’-dicarboxylic acid
(DTDC). Herein, synthesis and nitroaromatic sensing
studies will be discussed.

FAU's Office of Undergraduate Research and Inquiry hosts an annual symposium where students engaged in undergraduate research may present their findings either through a poster presentation or an oral presentation.

Luminescent lanthanide containing coordination polymers and metal-organic frameworks hold great potential in many applications due to their distinctive spectroscopic properties. While the ability to design coordination polymers for specific functions is often mentioned as a major benefit bestowed upon these compounds, the lack of a meaningful understanding of the crystal engineering and luminescence in lanthanide coordination polymers remains a significant challenge toward functional design. Currently, the study of luminescence attributed to these compounds is based on the antenna effect as derived from molecular systems, where organic antennae are used to facilitate lanthanide-centered luminescence. This molecular based approach does not take into account the unique features of extended network solids, particularly the formation of band structure. By comparing molecular and band-based approaches, it was determined that the band structure of the organic sensitizing linker needs to be considered when evaluating the luminescence of lanthanide coordination polymers. This new model, as well as work on the crystal engineering and sensor applications of these materials will be presented.

The organic linker 1,2,4,5-benzenetetracarboxylic acid (BTC) has been widely used in the construction of lanthanide metal-organic frameworks (MOFs) due the high symmetry and versatile nature of its structure. Under identical hydrothermal reaction conditions, it was discovered that lanthanide BTC MOFs will form one of four unique structures based on its location in the series (La-Sm, Eu-Tb, Dy-Tm, Yb-Lu). This is uncommon in LOF materials, as in many cases the same compound can be produced for all of the lanthanides or two different structures may be observed for the first and second half of the series. Descriptions and comparisons of these structures as discussed herein, noticeably the decrease in coordination number and the lanthanide-oxygen bond lengths as the lanthanide atomic number increases. This thesis also attempts to use these compounds to catalyze a model mixed-aldol reaction. Two closely related BTC compounds from yttrium and uranium are also presented. The structure of the yttrium BTC MOFs was identical to that of the Eu, Gd and Tb compounds.

The focus of this thesis is to develop lanthanide (Ln) luminescent materials through the exploration of coordination polymers and nanomaterials. Herein, dimethyl-3,4- furanedicarboxylate acid undergoes hydrolysis under hydrothermal conditions to form coordination polymers with lanthanide ions. The resulting coordination polymers exhibited luminescent properties, with quantum yields and lifetimes for the Eu-and Tb-CP of 1.14+-0.32% and 0.387=-0.0001 mx, and 3.33=-0.82% and 0.769=-0.006 ms, respectively. While the incorporation of lanthanides was not achieved in this work, progress toward the production of pure phase InP in the nanoregime has been made, using a low-cost, hydrothermal method. Through SEM and PXRD conflict, it is believed that pure INP particles with a size range of 58-81 nm were successfully synthesized.