Skip to main content

Metallocomplexes of macrocyclic compounds for photonic devices

Periodic Reporting for period 2 - METCOPH (Metallocomplexes of macrocyclic compounds for photonic devices)

Reporting period: 2017-01-01 to 2018-12-31

The project combines the ideas of organic chemistry, photochemistry and spectroscopy of metallocomplexes of macrocyclic compounds (MMCs) for applications in quantum information processing, sensing, switching and amplification. The project aims at focusing efforts of five research groups with extended and complementary competence in their respective research fields on gathering of spectroscopic information and photochemistry characterization of MMCs for future development of optical devices (e.g. organic light emitting devices, light emitting electrochemical cells, sensors and light emitting transistors) based on newly synthesized compounds.
Synthesis and extensive studies on novel, more effective and photostable materials will accelerate development of optical devices with reduced energy consumption and low production costs. What is important, the project fulfills the society demand in development of green chemistry products and methodologies preventing pollution and reducing consumption of nonrenewable resources.
The overall project objectives can be formulated as follows:
• Development of new approaches for the synthesis and purification of MMCs with predetermined spectroscopic and photophysical features;
• Investigation of molecular structure and energy deactivation pathways upon photoexcitation of novel MMCs;
• The study of behavior of MMCs upon the influence of the host matrices and different procedures/conditions of samples preparation;
• Exploration and analysis of the physical and chemical mechanisms of manipulation of the optical response of MMCs upon continuous and pulsed irradiations.
The first year of the project was dedicated to synthesis of different free-based macrocyclic cores, organic ligands and metallocomplexes based on combining of parent core with peripheral substituents. A series of substituted isomers of metallocomlexes of porphyrazine, porphyrin, phthalocyanine and porphycene as well as pincer metallocomplexes were successfully synthesized.
The photophysical/spectroscopic data for selected new metallocomplexes were gathered during second year of the project. Performed work obeys systematic investigations of the conformational structures and stability of metallocomplexes in different media (crystal, metal surface, solution or polymeric films). MMCs with simplest chemical structure exhibit in solution stable and reproducible spectral and photophysical characteristics. It is worth to mention that the conformational stability and the photophysical properties of MMCs depend significantly on various of internal and external reasons. The modification of the structure with different substituents, ligands coordination to the central metal atom or essential distortion of the MMCs macrocycle in dependence on type of central metal ion are internal factors influencing the chemical structure of mentioned compounds. The external factors are: solvents properties (viscosity, polarity, hydrogen bonding), interaction with metallic surfaces, steric hindrance in polymeric films or temperature and pressure. In result, the structure and symmetry of the MMC may be essentially disturbed what, in consequence, can lead to modification of spectral and photophysical characteristics. Influence of all the types of factors on conformational stability and structure of MMCs were studied during second year of the project.
During the third year of the project, theoretical chemists performed mutual quantum chemical modeling of the tetrapyrrolic cores topology in dependence on substituents in order to understand the effect of different modifications of the cores geometry on the electronic properties of the singlet and triplet excited states of the MMCs. For example, the dependence of photophysical properties of novel palladium metallocomplexes was studied for series of octaethylporphyrins with increasing number of aryl substituents.
The last year of the project was dedicated to selection of functionalized MMCs suitable for various applications such as optical sensors and OLEDs.
In particular, a range of MMCs based on matalloporphirines and metallophthalocyanines along with organo-transition metal complexes were investigated. Several promising materials for application as optical sensors of temperature and oxygen were identified. Long excited state lifetimes make some of these materials promising agents for singlet oxygen generation - a phenomenon crucial for modern photodynamic treatment schemes for instance for cancer. A new class of metal complexes displaying efficient thermally activated delayed fluorescence at ambient temperature was found. These silver complexes display the shortest TADF luminescence times so far found for TADF materials and deliver compounds with photoluminescence quantum yields approaching unity. Thus, this class of coumpounds represents particularly attractive materials for OLED applications.
The research and innovation contributions of the project were based on the synthesis and characterization of novel luminescent metallocomplexes for design of new types of devices for applications in modern nano- and photonic technologies.
The key impact of the project was a creation of collaboration between scientific groups from five countries. The combination of different skills of participants made possible to obtain a series of new photonic materials and begin the characterization of their properties for future applications. The teams participated in the project joined forces in order to design new MMC compounds and to investigate their fundamental (optical) properties using modern experimental techniques and methodologies. Consortium of teams from EU and Third countries in METCOPH project allows the efficient exploitation of innovative results towards industrial and commercial applications, with obvious benefit to the EU competitiveness in the global market.
The multidisciplinary character of the Project is crucial for sharing and improvement of scientific skills of the participants in different scientific fields. Young scientists from different research groups get the expertise and improve their skills in such fields as molecular spectroscopy, photophysics and photochemistry, theoretical modelling, optical microscopy and synthesis. New skills and experiences are especially important for early-stage participants of the project from Third Countries (Ukraine and Belarus). The project opens perspectives for realization of scientific careers either in the academic or industrial areas of EU.
The non-scientific impact of the project is possibility of cultural exchange and improvement of language skills (English, Polish, Russian). Friendly collaboration between EU and Third countries teams allows not only to exchange research expertise but also promotes international neighborhood relationships in Europe.
The project actions pursued to maintain an appropriate gender balance in all activities. 40% of participants of the project are female scientists. Other important aspect is to keep the right work-life balance that allows young parents to continue their scientific career. Therefore project takes into account flexible work hours for all participants declaring such needs.
During the project, the process of continuous information exchange and collaboration between the research groups from Poland, Germany, Israel, Belarus and Ukraine result in successful realization of planned deliverables and tasks.