# name
Synthesis and kinetics of photoisomerization processes of water soluble Pt(II) compounds

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Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2026, Tutora: Montserrat Sofía Ferrer García

# metadata.dc.description.abstract[].value
This study focuses on the synthesis of water-soluble square-planar Pt(II) complexes containing the azobenzene ligand 4-phenylazopyridine (Phpy) via substitution reactions from a Pt(II) diamine (TMEDA) precursor. The aim of this work is to investigate the cis-trans isomerization mechanism of the azobenzene coordinated to the metal center, with the goal of achieving a deeper understanding of this process.
A comprehensive study aimed at the synthesis of [Pt(Phpy)2TMEDA]2+ was carried out. Initial attempts employed [Pt(H2O)2TMEDA](OTf)2 as a building block; however, no reaction was observed. The Pt(II) precursor was subsequently replaced with the literature reported “[Pt(NO3)2TMEDA]” complex. It was found that the nitrate building block was not well characterized in the literature and the synthesis described led to the dinuclear complex [Pt2(OH)2TMEDA2](NO3)2 instead. Nevertheless, the latter compound did not allow the obtention of the desired azoderivative. Thus, a different precursor was selected [Pt(MeCN)2TMEDA](OTf)2. After a study to optimize the reaction conditions, the bisazo complex [Pt(Phpy)2TMEDA](OTf)2 was successfully isolated and fully characterized. Furthermore, later studies enabled the obtention of the monoazo analogue [Pt(MeCN)(Phpy)TMEDA](OTf)2.
A brief investigation under the same reaction conditions was carried out using different azobenzenes bearing appended isocyanide moieties to evaluate whether this synthetic approach could be extended to other ligands. However, these attempts did not afford the targeted products.
Once the desired products were obtained, a kinetico-mechanistic study of the thermal cis-trans isomerization in different solvents of the coordinate azobenzene ligands was carried out. The corresponding activation parameters were determined, and a mechanism of isomerization proposed. The availability of both mono- and bisazo complexes allowed the investigation of the existence of cooperative effects, which to date have not been unambiguously demonstrated in square-planar platinum(II) complexes containing two azobenzene ligands in cis position.

# metadata.dc.rights[].value
cc-by-nc-nd (c) Valenzuela Gimeno, Neus, 2026

# metadata.dc.title[].value
Synthesis and kinetics of photoisomerization processes of water soluble Pt(II) compounds

# metadata.dc.title.alternative[].value
Síntesi i estudi cinètic de processos de fotoisomerització de compostos de Pt(II) solubles en aigua