title: Excited state properties of photofunctional coordination compounds with tri- and tetradentate chromophores
title: from photophysical characterization to potential applications
titleType: Subtitle
Creators: name: Godinez-Loyola, Yokari
Publisher: name: University of Muenster, Institutional Repository MIAMI
Year: 2025
Subjects: subject: 540 Chemistry and allied sciences

description: Photolumineszente Koordinationsverbindungen sind für Anwendungen wie Bioimaging, Sensorik und Photokatalyse entscheidend. Diese Arbeit untersucht die angeregten Zustände von PtII-Komplexen mit tridentaten Liganden und Phthalocyaninen. Eine Reihe von PtIIKomplexen mit Bis-(triazol)-pyridin- und Bis-(tetrazolat)-pyridin-Liganden wurde synthetisiert und photophysikalisch charakterisiert. Die Ergebnisse zeigen, wie Asymmetrie und die elektronische Natur der Liganden die Eigenschaften beeinflussen. Zudem wurden Phthalocyanine mit verschiedenen Metallkationen hinsichtlich ihrer elektrochemischen und photolumineszenten Eigenschaften untersucht. Die Herstellung von Nanohybridmaterialien verbesserte die Löslichkeit und zeigte Potenzial als MRT-Kontrastmittel. Diese Ergebnisse liefern eine Grundlage für multifunktionale Bildgebungsmittel mit Potenzial für medizinische Diagnostik.
description: Chapter 1. Introduction ..... 1 
1.1 History of the physics of light ..... 1 
1.2 Brief introduction to luminescence ..... 2 
1.3 Absorption ..... 3 
1.4 Excited state deactivation pathways ..... 5 
1.5 Photophysical parameters ..... 9 
1.6 Transition metal complexes (TMCs) ..... 11 
 1.6.1 Valence bond theory (VBT) ..... 12 
 1.6.2 Crystal field theory (CFT) and ligand field theory (LFT) ..... 13 
 1.6.3 Molecular orbital theory (MOT) ..... 15 
1.7 Electronic spectrum of TMCs ..... 18 
1.8 Molecular symmetry ..... 20 
1.9 PtII complexes ..... 25 
1.10 Phthalocyanines (Pcs) ..... 26 
1.11 References ..... 27 
Chapter 2. Photophysical characterization techniques ..... 35 
2.1 UV-visible absorption spectroscopy ..... 35 
2.2 Photoluminescence spectroscopy ..... 36 
2.3 Time-resolved photoluminescence spectroscopy ..... 36 
2.4 Photoluminescence quantum yields ..... 40 
2.5 Transient-absorption spectroscopy ..... 41 
2.6 References ..... 43 
Chapter 3. Photoluminescent PtII complexes ..... 44 
3.1 Introduction ..... 44 
 3.1.1 Generalities of platinum chemistry ..... 44 
 3.1.2 Photoluminescence properties of PtII complexes ..... 45 
 3.1.3 Influence of the ligand design on the photoluminescence properties of PtII
complexes ..... 45 
3.2 Project outline ..... 54 
3.3 Aims ..... 54 
 3.3.1 General aim ..... 54 
 3.3.2 Particular aims ..... 55 
3.4 Results and Discussion ..... 55 
 3.4.1 Synthesis ..... 55 
 3.4.2 Photophysical characterization for liquid solutions at rt ..... 56 
 3.4.3 Photophysical characterization in glassy matrices of 2-MeTHF at 77 K ..... 60 
3.5 Conclusions ..... 63 
3.6 Perspectives ..... 64 
3.7 Experimental details ..... 65 
 3.7.1 Reagents ..... 65 
 3.7.2 Solvents ..... 65 
 3.7.3 Nuclear magnetic resonance (NMR) ..... 65 
 3.7.4 Electrospray ionization (ESI). ..... 65 
 3.7.5 Synthesis of ligand precursors ..... 65 
3.7.5.1 Synthesis of bis-CF3-trz ..... 65 
3.7.5.2 Synthesis of bis-tBu-trz ..... 66 
3.7.5.3 Syntheis of CF3-trz-ttz ..... 68 
 3.7.5.4 Syntheis of tBu-trz-ttz ..... 69 
 3.7.5.5 Syntheis of bis-ttz ..... 71 
 3.7.6 Synthesis of the PtII precursor ..... 71 
 3.7.6.1 Synthesis of [Pt(DMSO)2Cl2] ..... 71 
 3.7.7 Synthesis of the PtII complexes ..... 72 
 3.7.7.1 General procedure ..... 72 
3.7.7.2 Synthesis of Pt(bis-CF3-trz)(4-AmylPy) ..... 72 
3.7.7.3 Synthesis of Pt(bis-tBu-trz)(4-AmylPy) ..... 73 
3.7.7.4 Synthesis of Pt(CF3-trz-ttz)(4-AmylPy) ..... 73 
3.7.7.5 Synthesis of Pt(tBu-trz-ttz)(4-AmylPy) ..... 74 
3.7.7.6 Synthesis of Pt(bis-ttz)(4-AmylPy) ..... 75 
 3.7.8 Photophysical characterization..... 76 
3.7.8.1 UV-visible absorption spectroscopy ..... 76 
3.7.8.2 Steady-state and time-resolved photoluminescence spectroscopy ..... 76 
3.7.8.3 Photoluminescence quantum yields ..... 76 
3.8 References ..... 76 
Chapter 4. Photophysical characterization of phthalocyanines ..... 83 
4.1 Introduction ..... 83 
 4.1.1 Generalities about phthalocyanines ..... 83 
 4.1.2 Synthesis of phthalocyanines ..... 84 
 4.1.3 Absorption spectra of Pcs and MPcs ..... 86 
 4.1.4 Photoluminescence of Pcs and MPcs ..... 89 
4.2 Project outline ..... 92 
4.3 Aims ..... 93 
 4.3.1 General aim ..... 93 
 4.3.2 Particular aims ..... 93 
4.4 Results and discussion ..... 93 
 4.4.1 UV-visible absorption spectroscopy ..... 93 
 4.4.2 Cyclic voltammetry (CV) ..... 95 
 4.4.3 Spectroelectrochemistry (SEC) ..... 97 
 4.4.4 Photophysical properties in liquid solutions at rt ..... 99 
 4.4.5 Photophysical properties in glassy matrices at 77 K ..... 101 
 4.4.6 Preparation of PMMA films ..... 103 
 4.4.7 Photophysical properties of PMMA films ..... 105 
 4.4.8 Transient absorption spectroscopy ..... 108 
 4.4.9 Activation of the fluorescence of NiPc ..... 111 
4.5 Conclusions ..... 113 
4.6 Experimental details ..... 114 
 4.6.1 Reagents ..... 114 
 4.6.2 Solvents ..... 114 
 4.6.3 Cyclic voltammetry (CV) ..... 114 
 4.6.4 Spectroelectrochemistry (SEC) ..... 115 
 4.6.5 Theoretical methods ..... 116 
 4.6.6 Photophysical measurements ..... 117 
 4.6.6.1 UV-visible absorption spectroscopy ..... 117 
4.6.6.2 Steady-state and time-resolved photoluminescence spectroscopy 117 
4.6.6.3 Transient absorption spectroscopy ..... 117 
 4.6.7 Steady-state and time-resolved measurements of PMMA films at rt ..... 118 
 4.6.8 Preparation of the PMMA films ..... 118 
 4.6.9 Temperature-dependent steady-state and time-resolved spectroscopy of
PMMA films ..... 118 
4.6.10 Scanning tunneling microscopy-induced luminescence (STML) ..... 118 
4.7 References ..... 119 
Chapter 5. Preparation and photophysical characterization of nanohybrids
(Laponite-Pcs) as magnetic resonance imaging (MRI) contrast agents ..... 125 
5.1 Introduction ..... 125 
 5.1.1 Dyes, pigments, and inks ..... 125 
 5.1.2 Sensors ..... 125 
Chemical sensors ..... 125 
Biosensors ..... 126 
 5.1.3 Catalysis ..... 127 
Oxidative reactions ..... 127 
Electrocatalysis ..... 127 
Polymerization catalysis ..... 127 
Photoredox catalysis ..... 127 
 5.1.4 Photovoltaic applications ..... 129 
 5.1.5 Photodynamic therapy (PDT) ..... 130 
 5.1.6 Photothermal therapy (PTT) ..... 134 
 5.1.7 Bioimaging ..... 135 
Magnetic resonance imaging (MRI) ..... 135 
5.2 Laponite ..... 137 
5.3 Project outline ..... 141 
5.4 Aims ..... 142 
 5.4.1 General aim ..... 142 
 5.4.2 Particular aims ..... 142 
5.5 Results and discussion ..... 142 
 5.5.1 Physisorption ..... 142 
 5.5.2 Characterization of the nanohybrids ..... 143 
 5.5.2.1 UV-visible absorption spectroscopy, EPR, and MALDI-TOF
 ..... 144 
 5.5.2.2 Photophysical properties in solid state
 ..... 151 
5.5.2.3 Photophysical properties in aqueous dispersions ..... 152 
5.5.2.4 Photophysical properties in hydrogels ..... 154 
 5.5.3 Magnetic resonance imaging (MRI) ..... 158 
 5.5.4 Conclusions ..... 160 
 5.5.5 Perspectives ..... 160 
5.6 Experimental details ..... 161 
 5.6.1 Reagents ..... 161 
 5.6.2 Solvents ..... 161 
 5.6.3 Physisorption of Pcs onto Laponite ..... 161 
 5.6.4 Preparation of the hydrogels ..... 161 
 5.6.5 Photophysical measurements ..... 162 
 5.6.5.1 UV-visible absorption spectroscopy ..... 162 
5.6.5.2 Steady-state and time-resolved photoluminescence spectroscopy 162 
 5.6.6 Electron paramagnetic resonance (EPR) ..... 162 
 5.6.7 MALDI-TOF ..... 163 
 5.6.8 Magnetic resonance imaging (MRI) ..... 163 
 5.6.9 Rheology measurements ..... 163 
5.7 References ..... 164 
Chapter 6. Conclusions and perspectives ..... 175 
Appendix 1. Collaboration partners ..... 177 
Appendix 2. Curriculum vitae ..... 178 
Appendix 3. NMR and mass spectra ..... 182 
3.1 NMR and mass spectra of the ligand precursors ..... 182 
3.2 NMR and mass spectra of the PtII complexes ..... 201