Photochemical Sciences Ph.D. Dissertations

Probing the photophysical and mechanical properties of supramolecular polymers by utilizing dynamic coordination bonds

Date of Award

2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Photochemical Sciences

First Advisor

Alexis D. Ostrowski (Committee Chair)

Second Advisor

Francisco Cabanillas (Other)

Third Advisor

Joseph C. Furgal (Committee Member)

Fourth Advisor

Alexander N. Tarnovsky (Committee Member)

Abstract

To correlate and be able to tune the photophysical properties of molecular scale chromophores with the mechanical properties of the macroscale supramolecular polymer such as viscosity, modulus etc. is a complex phenomenon. To tune these properties, we utilize dynamical coordination bonds such as Metal-Ligand interactions. In this work, we present how we can use the photophysical properties specifically probing excited state arising from these tunable dynamical interactions to probe the mechanical properties of the macroenvironment real time in-situ. Utilizing this approach, we were able to detect the viscosity of supramolecular polymeric assembly by probing emission lifetime from triplet electronic state of [Cu(diptmp)2]2+. However, this correlation is not quantitatively ubiquitous in every polymeric host. We probed the reversibility of the polymeric assembly by swelling and deswelling the polymer assembly which is attributed to micro-viscosity. The photophysical changes were of significant magnitude to be able to detect even small reversible changes during swelling and deswelling the polymer. Furthermore, worked on synthesizing a bio-based polymer and made a composite material with multiple ligand moieties. We present how these moieties interact with the polymeric environment and quantify them through their affinity to different metals. The photophysical changes in emission of a bio-based Cu-curcumin polymeric composite material upon applying stress to the composite material has been discussed. We also present to show whether we can induce the photophysical changes in NIR emission of a water soluble [Cr(ddpd)3]3+ complex termed as molecular ruby exhibiting upon subjecting it to thin supramolecular films with increasing modulus and looked at its stress-response.

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