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Full-Text Articles in Physical Sciences and Mathematics

Pentacene-Fused Diporphyrins, Lin Jiang, James Engle, Ross Zaenglein, Alex Matus, Christopher Ziegler, Hong Wang, Martin Stillman Sep 2015

Pentacene-Fused Diporphyrins, Lin Jiang, James Engle, Ross Zaenglein, Alex Matus, Christopher Ziegler, Hong Wang, Martin Stillman

Christopher J. Ziegler

In this work, we report the synthesis, spectroscopic characterization, and theoretical analysis of a linearly conjugated pentacene-fused porphyrin dimer and cross-conjugated quinone-fused dinaphtho[2,3]porphyrins. These multichromophoric systems display non-typical UV-visible absorptions of either porphyrins or pentacenes/quinones. UV-visible, emission and magnetic circular dichroism (MCD) spectroscopy suggest strong electronic interactions among the multichromophores in the system. DFT calculations revealed the delocalization of the HOMOs and LUMOs spanning the entire dimer and linker assembly. The pentacene-fused porphyrin dimer is significantly more stable than both the corresponding pentacene and the heptacene derivatives. The availability of these huge π-extended and electronically highly interactive multichromophoric systems promises …


Combined Mcd/Dft/Tddft Study Of The Electronic Structure Of Axially Pyridine Coordinated Metallocorroles, Hannah Rhoda, Laura Crandall, G. Geier, Christopher Ziegler, Victor Nemykin Sep 2015

Combined Mcd/Dft/Tddft Study Of The Electronic Structure Of Axially Pyridine Coordinated Metallocorroles, Hannah Rhoda, Laura Crandall, G. Geier, Christopher Ziegler, Victor Nemykin

Christopher J. Ziegler

A series of metallocorroles were investigated by UV−vis and MCD spectroscopies to investigate similarities and differences in the electronic structure and spectroscopy of the closed- and open-shell metallocorroles. Similar to the free-base H3tpfc, inspection of the MCD Faraday B-terms for all of the macrocycles presented here revealed that a ΔHOMO < ΔLUMO condition is present for each complex, which results in an unusual sign-reversed sequence for π−π* transitions in their MCD spectra.


Synthesis Of Dimeric Rhenium Phenylenediimine Conjugates, Christopher Ziegler, J Bass, C Bogdanowicz, R Herrick, A Hasheminasab Sep 2015

Synthesis Of Dimeric Rhenium Phenylenediimine Conjugates, Christopher Ziegler, J Bass, C Bogdanowicz, R Herrick, A Hasheminasab

Christopher J. Ziegler

No abstract provided.


Improved Synthesis Of [Re(Co)(3)(H2o)(3)]Br And Its Derivatives, Gerard Kerins, Joshua Farrell, Richard Herrick, Christopher Ziegler Sep 2015

Improved Synthesis Of [Re(Co)(3)(H2o)(3)]Br And Its Derivatives, Gerard Kerins, Joshua Farrell, Richard Herrick, Christopher Ziegler

Christopher J. Ziegler

Rhenium has been studied at length as a non-radioactive chemical analog to Technetium, a popular diagnostic imaging agent employed in nuclear medicine and biology. This study details a new synthetic method for preparing [Re(CO)3(H2O)3]Br as well as multiple derivatives of this complex using tridentate ligands. Full synthetic details and characterization will be pre


Enhanced Helical Folding Of Ortho-Phenylenes Through The Control Of Aromatic Stacking Interactions, Sanyo Mathew, Laura Crandall, Christopher Ziegler Sep 2015

Enhanced Helical Folding Of Ortho-Phenylenes Through The Control Of Aromatic Stacking Interactions, Sanyo Mathew, Laura Crandall, Christopher Ziegler

Christopher J. Ziegler

The ortho-phenylenes are a simple class of foldamers, with the formation of helices driven by offset aromatic stacking interactions parallel to the helical axis. For the majority of reported o-phenylene oligomers, the perfectly folded conformer comprises perhaps 50–75% of the total population. Given the hundreds or thousands of possible conformers for even short oligomers, this distribution represents a substantial bias toward the folded state. However, “next-generation” o-phenylenes with better folding properties are needed if these structures are to be exploited as functional units within more complex architectures. Here, we report several new series of o-phenylene oligomers, varying both the nature …