SOLVENT-TUNING OF A Feⁱⁱ EXCITED STATE TOWARD UNDERSTANDING LIGAND DESIGN

Malme, Justin Thomas

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https://hdl.handle.net/2142/122703 Copy

Description

Title

SOLVENT-TUNING OF A Feⁱⁱ EXCITED STATE TOWARD UNDERSTANDING LIGAND DESIGN

Author(s)

Malme, Justin Thomas

Contributor(s)

• Vura-Weis, Josh
• Ren, Tong
• Gautam, Prakhar
• Boedicker, Lauren
• Clendening, Reese

Issue Date

2023-06-20

Keyword(s)

• Electronic structure
• potential energy surfaces

Abstract

Cyanide-containing d⁶ transition metal complexes are known to exhibit strong solvatochromism of their MLCT band, but also a solvent-lifetime dependence. These effects are understood to be modulated by second-shell donor-acceptor interactions at the cyanide nitrogen, the strength of which are dictated by solvent acceptor number, a measure of relative Lewis acidity. These modulations can be understood as altering the σ-donor π-acceptor character of the cyanide ligands. A recently reported long-lived Feⁱⁱ complex, Fe(HMTI)(CN)₂, exhibits a biphasic solvent-lifetime relationship, with a rising and falling edge as acceptor number increases, making it difficult to pin down the nature of the relationship. In this work, a variant of the Fe(HMTI)(CN)₂, Fe(TIM)(CN)₂ (TIM=2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene) and its bound lewis acid counterpart, Fe(TIM)(CNBPh₃)₂, are investigated. Fe(TIM)(CN)₂ exhibits a largely monophasic solvent-lifetime relationship, with lifetime falling nearly exponentially as solvent acceptor number rises. This relationship is probed more closely by UV-Vis transient absorption experiments, and DFT calculations, to elucidate the effects of modulating σ-donor π-acceptor character of ligands bound to Feⁱⁱ chromophores.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122703

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