Helicenes are polycyclic aromatic compounds in which the benzene rings are connected in ortho positions leading to screw-shaped molecules. They exhibit helical chirality even though they do not contain any asymmetric carbon. Helicenes’ chirality results from the fact that clockwise and counterclockwise helices are non-superimposable. Both enantiomers are stable and isolable forms. Furthermore, their intriguing semiconductivity was foreseen opening their potential applications in organic electronic devices. Recently, we have developed a revised microwave photodehydrocyclization procedure for preparation of various substituted helicenes in multigram scale. Our effort is directed toward synthesis and utilization of carbo- and heterohelicenes in the following topics:

    • Multigram scale production of various helicenes

 We developed a revised photocyclization method for preparation of [n]helicenes and their derivatives on a multigram scale.
scheme helicene 1_600dpi

    • Design and photochemical synthesis of new helicenes

 Using the concept described above we are focusing on a large scale preparation of various helicene derivatives or heterohelicenes.

scheme helicene 2_600dpi

scheme helicene 3_600dpi

    • Supramolecular organization of aromatic systems, π-π interactions

 Combining the electron rich and electron deficient starting materials we are interested in a CT-complexes formation.

  CT

    • Development of chiral stationary phases membranes

The chirality of non-racemic helicenes can be employed in construction of chirally endowed materials such as HPLC stationary phases or membranes.

    • Semi-conductive polymers based on helicene scaffold

Conductive organic polymers can be used in two main electronics applications – materials used to construct various devices e.g. PLED (polymer light emitting diodes, part of OLED, organic light emitting diodes), OSC (organic solar cells), OTFT (organic thin film transistors) and as selective layers in chemical sensors. Thin films made by polymeric semiconductors or by particular molecules embody excellent electron mobility and they serve as fundamental structural elements of printed electronics or hybrid inorganic-organic devices. In contrast to common inorganic components based on silicon the energy expenditure of OTFT fabrication is very low and the technology allows the use of common printing techniques.


Our goal is to prepare conjugated thiophene-based and polyacetylene-based polymer systems containing helicene substituents which would exhibit promising electrical and optical properties. All conjugated polymers contain π-electrons which are highly delocalized and easily polarizable. These features play important roles in the electrical and optical properties of polyconjugated systems, making them rather different from conventional conductors.

electro

    • Helically chiral systems in enantioselective organo- and photocatalysis

Helicenes are very promising compounds in enantioselective catalysis, due to their chirality and considerable steric hindrance. Attachment of helicene moiety to the structure of flavins leads to new helically chiral flavins, which are not only suitable for various organocatalytic redox reactions, but their unique properties allows for their use in photocatalysis as well.

flavin

    • Design of helically chiral ligands and their transition-metal complexes

Coordination chemistry of helicenes and their use as chirality inductors is still strongly under-developed. Among privileged lignads exhibiting central, axial or planar chirality, use of helically chiral ligands in transition metal catalysis is still very rare. We are focusing on helical phosphines and their transition-metal complexes potentially usable in homogeneous asymmetric catalysis.

trans_PM