BIFUNCTIONAL BF2 COMPLEXES OF POLYDENTATE BIS(AMIDINATES): SYNTHESIS, STRUCTURES, AND PHOTOLUMINESCENCE PROPERTIES

<p>Five novel bis(difluoroboryl)-bis(amidinates) <strong>L^1-5</strong>(BF₂)₂ were synthesized in yields of 12−33%. Ethylene-linked bis(difluoroboryl)-bis(amidinates) represent an unprecedented class of new bifunctional fluorophores that have the potential to serve as air stable indicators and sensors for applications in medicine, materials science, and supramolecular chemistry.</p> <p>The syntheses of the precursor bis(amidines) <strong>L^1-5</strong>H₂ were carried out through a proven three-step method of by treating 2 equivalents of pivoloyl chloride with ethylene diamine in CH₂Cl₂ to yield a bis(amide) as a colorless powder in 76% yield. The bis(amide) was subsequently reacted with 2 equivalents of PCl₅in CH₂Cl₂ to give the corresponding bis(imidoylchloride) as a yellow oil in 86% yield. Subsequent aminolysis with 2-aminopyridine, 4-methyl-2-aminopyridine, 6-methyl-2-aminopyridine, 4,6-dimethyl-2-aminopyridine, and 2-aminoquinoline yielded the polydentate bis(amidines) as colorless solids (61−71%).</p> <p><strong>L^1-5</strong>H₂were stirred in toluene at room temperature with 2 equivalents of BF₃∙OEt₂ in the presence of excess trimethylamine to form <strong>L^1-5</strong>(BF₂)₂ as colorless solids in 12−33% yields. Compounds <strong>L^1-4</strong>(BF₂)₂ were characterized by NMR, IR, and UV-Vis spectroscopy as well as mass spectrometry and elemental analysis. For all four diboron-bis(amidinate) complexes, the molecular structures are presented. The photoluminescent properties of <strong>L^1-4</strong>(BF₂)₂ were investigated by their excitation, and emission spectra, as well as quantum yield determinations and the photostability tests both in solution (THF) and in the solid-state.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2021

Author dc:creator

• Calderon-Diaz, Alvaro

Contributors dc:contributor

• Michael Stollenz, PhD
• Daniela Tapu, PhD
• Thomas Leeper, PhD

• Fluorescence
• Luminescence
• Solid-state
• bis(Amidine)
• bis(amidinate)
• boron
• Chemistry

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/43

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1044