Benzo (Aza) Di- and Tripyrrins, and Their Metal Complexes

Abstract

This thesis continues the investigation of our group's synthesis of benzo-fused aza di- and tripyrrins. The main focus of this work is the complexation of these ligands with various metals. Therefore, symmetrical and unsymmetrical benzo azadipyrrins were successfully synthesised. The synthesis of benzo azatripyrrin was optimised in this work. The success of this objective led to the preparation of these compounds and various derivatives. The path to producing homoleptic complexes faced several obstacles. To solve this problem, many experiments were attempted with various purification techniques. Complexation of azatripyrrn was not achieved. A range of reaction conditions failed to reach our goal. These conditions were gradually modified until a breakup and decomposition were observed. On the other hand, the complexation of symmetrical and unsymmetrical benzo azadipyrrins proposed other difficulties. The main problems in this path were the produced complexes' purification and stability. Several attempts were made using different metals. Unlike azatripyrrin, successful complexation of azadipyrrin was achieved using palladium metal. The unsymmetrical azadipyrrin palladium complex was the first to be successfully synthesised and characterised in 1:1. Through ligand modification, a range of complexes containing ferrocene and thiophene groups were synthesised. While these derivatives are highly interesting in the organometallic field, the goal was to study the insertion behaviour of palladium metal. Modifying this successful technique led to the preparation of symmetrical azadipyrrin palladium complexes and their derivatives. Due to time constraints, these palladium complexation procedures were briefly tested with other metals in the preparation of azadipyrrin complexes. Additionally, test reactions were made to synthesise azatripyrrin palladium complexes. While the results are not conclusive, these tests are the seeds of further work.