The Effect of Methylene Spacers on the Spectral, Electrochemical, Structural, and Photophysical Properties and Electron Injection Dynamics of Bis(4,4'-disubstituted-2,2'- bipyridyl) Ruthenium(II) Dye Analogues and The Effect of Alkali Metal Ions on the Structure and Spectroscopy of a Tripodal Co(II) Complex Público

Lense, Sheri (2010)

Permanent URL: https://etd.library.emory.edu/concern/etds/qr46r145t?locale=pt-BR
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Abstract

Abstract
The Effect of Methylene Spacers on the Spectral, Electrochemical, Structural, and
Photophysical Properties and Electron Injection Dynamics of Bis(4,4'-disubstituted-2,2'-
bipyridyl) Ruthenium(II) Dye Analogues and
The Effect of Alkali Metal Ions on the Structure and Spectroscopy of a Tripodal Co(II)
Complex
By Sheri Lense

Variations of cis-dithiocyanatobis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) (N3), in which methylene spacers were inserted between the bipyridyl and carboxylic acid or methyl ester groups, were synthesized and characterized to study the effects of methylene spacers on the spectral, electrochemical, and structural properties and electron injection dynamics. The complexes exhibit very similar electronic absorption spectra that are blue-shifted with respect to the N3 dye. For all complexes, the reversibility of the Ru(II/III) couple increases with increasing linker length. The complexes with one methylene spacer are significantly less stable under reducing conditions than the complexes with two or three methylene spacers. Electron transfer from the modified dyes to TiO2 was also investigated. The injection yields are smaller for the modified dyes than for the N3 dye, likely because electron injection is slower, allowing for competing decay processes to become more competitive.

Part II of this thesis describes the coordination of alkali metal ions by tripodal Co(II) complexes. The alkali metal ions influence both the local and extended geometry of these complexes. Upon alkali metal ion coordination the ligand geometry around the transition metal ion changes from trigonal monopyramidal to trigonal bipyramidal and the solid-state structure takes on an extended form, with the transition metal complexes linked through shared alkali metal ions to form one-dimensional chains.

Table of Contents


Table of Contents
Section
Page

List of Figures

List of Tables

List of Schemes

Part I. The Effect of Methylene Spacers on the Spectral,
1
Electrochemical, Structural, and Photophysical Properties and Electron
Injection Dynamics of Bis(4,4'-disubstituted-2,2'-bipyridyl) Ruthenium(II)
Dye Analogues
Chapter I. Introduction
1
Section I-I. Solar Cells
1
Section I-II. Thin Film Solar Cells
1
Section I-III. Dye Sensitized Solar Cells (DSSCs)
4
Section I-IV. Improvements on the N3 Dye
7
Section I-V. Interfacial Electron Transfer from the Dye to TiO
11
2
Section I-VI. Outline for Part I of Thesis
16
Chapter II. The Effect of Methylene Spacers on the Spectral,
18
Electrochemical, Structural, and Photophysical Properties and Electron
Injection Dynamics of Bis(4,4'-disubstituted-2,2'-bipyridyl) Ruthenium(II)
Dye Analogues
Section II-I. Synthesis
18
Section II-II. Spectroscopy
23
Section II-III. Electrochemistry
27
Section II-IV. Structural Characterization
32
Section II-V. TiO Film Sensitization and Electron Injection Dynamics
34
2
Section II-VI. Conclusions
42
Section II-VII. Experimental Section and Supplementary Material
43
Part II. The Effect of Alkali Metals of the Structure and Spectroscopy
75
of a Tripodal Co(II) Complex
Chapter III. Introduction
75
Section III-I. Alkali(ne Earth) Metal Cations in Biology
76
Section III-II. Ca2+ in Photosystem II
78
Section III-III. Synthetic Ligands for Alkali(ne earth) Ions: Crown
80
Ethers
Section III-IV. Transition Metal Coordination
83
Section III-V. Binucleating Ligands
83
Section III-VI. Heterodinuclear Transition Metal-Alkali(ne Earth) Ion
84
Ligands
Section III-VII. Implications of Alkali(ne) Earth Cations for the
86
Reactivity of Transition Metal Ion Complexes
Section III-VIII. Alkali(ne Earth) Cation Sensors and Molecular Switches
92
Section III-IX. Applications to Crystal Engineering
96
Section III-X. Outline for Part II of Thesis
99
Chapter IV. Initial Attempts at Heterodinuclear Ligand Design
100
Section IV-I. Ligand Design
100
Section IV-II. Synthesis and Characterization of LM and
[CoLM(NO3)]BPh4

101
Section IV-III. Synthesis and characterization of LBz_1, [CoLBz_3](PF6)2 and [ZnLBz_3](PF6)2
109
Section IV-IV. Experimental Section and Supplementary Material
114
Chapter V. The Influence of Alkali Metals on the Local and Extended Structure of a Tripodal Transition Metal Complex
122
Section V-I. Overview
122
Section V-II. Synthesis
123
Section V-III. Structural Characterization
126
Section V-IV. NMR Spectroscopy
135
Section V-V. UV-Visible Absorption Spectroscopy and Calculation of Binding Constants
137
Section V-VI. IR Spectroscopy
145
Section V-VII. Electrochemistry
146
Section V-VIII. Ligand Design
152
Section V-IX. Conclusions
156
Section V-X. Experimental Section and Supplementary Material
157
References
177

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