Project

Discipline

Pyrrole; Calix[4]pyrrole; Macrocyclic Ligands; Catalysis; Triphenylene; Extended porphyrins; Discotic mesophases; Calix[4]pyrroles; Macrocylces; Reduction; Metal complexes

Lead
Lay summary
Lead:In our research we use calix[4]pyrroles as starting materials which are spontaneously formed by a simple chemical process known for more than 120 years. Calix[4]pyrroles are obtained without the need of external instruction. These classes of synthetic transformations have a flavor of spontaneous creation, a phenomenon, which is of general interest. These macrocycles are obtained by a simple process which is very similar to the biosynthetisis of the "pigments of life". They have attracted the attention of scientists interested in biosynthesis, prebiotic synthesis and natural products.Review:In contrast to the natural "pigments of life, the synthetic calix[4]pyrroles do not easily form transition metal complexes. Our group has proposed and developed a strategy, whereby the structurally blocked calix[4]pyrrole pyrroles can be transformed into efficient macrocyclic ligands. The reduction process studied in our group allows to obtain close relatives to the porphyrin-like "pigments of life". The four nitrogen ligands are in geometric positions close to the ones made available by the tetrapyrrolic cofactors. Different diastereomers of our novel ligand syntheticaly feasible and the influence of the relative configuration of the ligand on the metal complexation can be studied. Goal:The goal of our research is to make these novel and unique ligands available by studying new approaches to these ligand, by optimizing the reduction process used so far and by studying the properties of the ligands and their metal complexes.Significance:Our studies enlarge the structural variety of macrocyclices available to the chemists but also to other scientists. Metal complexes of macrocyclic ligands are good candidates for studies in catalysis, in material science, but also as sensors for studies of natural processes. The simplicity of the access studied in our group should make many different ligands available.

Direct link to Lay Summary

Last update: 21.02.2013

Active participation

Title	Year

Number	Title	Start	Funding scheme

Project A:Calix[4]pyrroles are known for over 100 years. We have been the first to reduce these easy to synthesize macrocylces. The ligand obtained have interesting structures and form metal complexes with transition metals. The synthesis of these reduced forms of calix[4]pyrroles and of analogues of these compounds are studied and their properties will be examined.Project B:Control of the supramolecular organization by optimizing the architecture of single molecules as building blocks constitutes a challenge in device fabrication. The discotic molecules, such as hexaalkoxy-triphenylene, self-organize by p stacking into columnar supramolecular structures facilitating a charge carrier transport along these one dimensional assemblies. The aim of this work is to connect two triphenylenes derivatives with a rigid linker, in order to control the self-organization of the discotic molecules and increase the supramolecular order of the hexagonal columnar mesophase.