Scanning Tunneling Microscopy Observations of Neutral and Mixed-Valence Organometallic Complexes

Doctoral Dissertation

Abstract

Low-temperature ultra-high-vacuum scanning tunneling microscopy (STM) is used to study di- and trinuclear iron-based organometallic molecules. Chemical oxidation of these molecules leads to mixed-valence species with interesting intramolecular charge-transfer properties. STM images of neutral molecules show symmetrical distribution of electron density across the metal centers because the metal centers are present in the same oxidation state. STM images of mixed-valence molecules show an asymmetric distribution of the electron density, indicating that the metal centers are present in diļ¬€erent oxidation states. I have found that the intramolecular charge-transfer rates depend on the geometry of the organic linker between the metal centers, and that these mixed-valence compounds retain their electronic properties when placed on a metal surface in the absence of bulk solvent. Comparison with theoretical STM images derived from constrained-density-functional theory (CDFT) calculations leads to the conclusion that the observed features in the STM images are electronic in nature. Investigation of mixed-valence dinuclear organometallic molecules with asymmetric electron state density may open up the possibility for their use in molecularly based electronic devices.

Attributes

Attribute NameValues
URN
  • etd-04082013-105353

Author Rebecca Carole Quardokus
Advisor Prof. S. Alex Kandel
Contributor Prof. S. Alex Kandel, Committee Chair
Contributor Prof. J. Daniel Gezelter, Committee Member
Contributor Prof. Prashant Kamat, Committee Member
Contributor Prof. Marya Lieberman, Committee Member
Degree Level Doctoral Dissertation
Degree Discipline Chemistry and Biochemistry
Degree Name PhD
Defense Date
  • 2013-04-04

Submission Date 2013-04-08
Country
  • United States of America

Subject
  • STM

  • mixed valence

  • scanning tunneling microscopy

Publisher
  • University of Notre Dame

Language
  • English

Record Visibility and Access Public
Content License
  • All rights reserved

Departments and Units

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