We are featured on JACS cover!

Our work on oxygen activation by some calcium complexes is featured on JACS cover.

Reaction of a Ca-TEMPO complex with O2 led to a unique calcium hydroperoxide and a heterometallic Ca/K peroxide. Combining experimental observations with computational investigations, a mechanistic rationalization was proposed for the reaction outcomes. The designed approach reveals a new versatile platform for O2 activation and advances the understanding of Ca/ROS systems.

Fresh Impetus in the Chemistry of Calcium Peroxides
by Arkadiusz Kornowicz, Tomasz Pietrzak, Krzesimir Korona, Michał Terlecki, Iwona Justyniak, Adam Kubas,* and Janusz Lewiński*
J. Am. Chem. Soc. 2024, 146, 28, 18938–18947

Group photo!

We thank dr Karol Karnowski who took few shots of our team in July 2024. Missing were dr M. Zienkiewicz-Machnik, prof. J. Sa, and dr M. Kochman.

Two new papers on OLEDs are out

Enjoy reading our two new papers where CoopCat team contributed with quantum chemical calculations:

An unprecedented roll-off ratio in high-performing red TADF OLED emitters featuring 2,3-indole-annulated naphthalene imide and auxiliary donors
by Magdalena Grzelak, Dharmendra Kumar, Michał Andrzej Kochman, Maja Morawiak, Gabriela Wiosna-Sałyga, Adam Kubas,* Przemysław Data* and Marcin Lindner*
Chem. Sci., 2024, 15, 8404-8413

Regioisomerism vs Conformation: Impact of Molecular Design on the Emission Pathway in Organic Light-Emitting Device Emitters
by Prasannamani Govindharaj, Aleksandra J. Wierzba, Karolina Kęska, Michał Andrzej Kochman, Gabriela Wiosna-Sałyga, Adam Kubas,* Przemysław Data,* Marcin Lindner*
ACS Appl. Mater. Interfaces 2024, 16, 18, 23654–23667

We welcome new PhD student!

We welcome Smith Pataraprasitpon – new PhD student who will work with dr Piekarski on the dynamics of charged triazoles (NCN Sonata project of dr Piekarski).

Four papers with our exp. collaborators

Happy to announce the publication of four new papers from our group!

In collaboration with the Institute of Organic Chemistry (M. Lindner group) and the Łódź University of Technology (P. Data group)
V-shaped donor–acceptor organic emitters. A new approach towards efficient TADF OLED devices
by Wojciech Derkowski, Dharmandra Kumar, Tomasz Gryber, Jakub Wagner, Maja Morawiak, Michał Andrzej Kochman, Adam Kubas,* Przemysław Data,* Marcin Lindner*

In collaboration with exp. group at IChF (R. Szmigielski), Leibniz Institute for Tropospheric Research (H. Herrmann group), and National Institute of Chemistry in Ljubljana (Grgić group)
Aqueous-phase photo-oxidation of selected green leaf volatiles initiated by radical OH radicals: Products and atmospheric implications
by Kumar Sarang, Tobias Otto, Sahir Gagan, Krzysztof Rudzinski, Thomas Schaefer, Martin Brüggemann, Irena Grgić, Adam Kubas,* Hartmut Herrmann,* Rafal Szmigielski*

In collaboration with exp. group at the University of Münster (PI: Olga García Mancheño)
Fine-Tuning Substrate–Catalyst Halogen–Halogen Interactions for Boosting Enantioselectivity in Halogen-Bonding Catalysis
Alica C Keuper, Kevin Fengler, Florian Ostler, Tobias Danelzik, Dariusz G Piekarski, Olga García Mancheño

In collaboration with experimental IChF groups (W. Nogala, T. Ratajczyk, S. Gawinkowski)
A reagentless amperometric biosensor for creatinine assay based on recombinant creatinine deiminase and N-methylhydantoin-sensitive CoCu nanocomposite
by Nataliya Stasyuk, Andriy Zakalskiy, Wojciech Nogala, Sylwester Gawinkowski, Tomasz Ratajczyk, Magdalena Bonarowska, Olha Demkiv, Oksana Zakalska, Mykhailo Gonchar

TV visited our lab

TVP Nauka (the science sub-channel of the main TV channel in Poland) visited our lab. Adam and Gosia gave an interview explaining what happens in the CoopCat lab. Below is a teaser. We will post here the final movie once it appears in TV. Stay tuned!

PNAS paper published!

We continue great collaboration with Kris Palczewski lab at the University of California Irvine.

Chromophore hydrolysis and release from photoactivated rhodopsin in native membranes

John D Hong, David Salom, Michał Andrzej Kochman, Adam Kubas, Philip D Kiser, Krzysztof Palczewski

For sustained vision, photoactivated rhodopsin (Rho*) must undergo hydrolysis and release of all-trans-retinal, producing substrate for the visual cycle and apo-opsin available for regeneration with 11-cis-retinal. The kinetics of this hydrolysis has yet to be described for rhodopsin in its native membrane environment. We developed a method consisting of simultaneous denaturation and chromophore trapping by isopropanol/borohydride, followed by exhaustive protein digestion, complete extraction, and liquid chromatography–mass spectrometry. Using our method, we tracked Rho* hydrolysis, the subsequent formation of N-retinylidene-phosphatidylethanolamine (N-ret-PE) adducts with the released all-trans-retinal, and the reduction of all-trans-retinal to all-trans-retinol. We found that hydrolysis occurred faster in native membranes than in detergent micelles typically used to study membrane proteins. The activation energy of the hydrolysis in native membranes was determined to be 17.7 ± 2.4 kcal/mol. Our data support the interpretation that metarhodopsin II, the signaling state of rhodopsin, is the primary species undergoing hydrolysis and release of its all-trans-retinal. In the absence of NADPH, free all-trans-retinal reacts with phosphatidylethanolamine (PE), forming a substantial amount of N-ret-PE (∼40% of total all-trans-retinal at physiological pH), at a rate that is an order of magnitude faster than Rho* hydrolysis. However, N-ret-PE formation was highly attenuated by NADPH-dependent reduction of all-trans-retinal to all-trans-retinol. Neither N-ret-PE formation nor all-trans-retinal reduction affected the rate of hydrolysis of Rho*. Our study provides a comprehensive picture of the hydrolysis of Rho* and the release of all-trans-retinal and its reentry into the visual cycle, a process in which alteration can lead to severe retinopathies.

Two new papers are out!

Tandem rigidification and π-extension as a key tool for the development of a narrow linewidth yellow hyperfluorescent OLED system

by Krzysztof Bartkowski, Paola Zimmermann Crocomo, Michał Andrzej Kochman, Dharmandra Kumar, Adam Kubas, Przemysław Data, Marcin Lindner

Hyperfluorescence (HF), a relatively new phenomenon utilizing the transfer of excitons between two luminophores, requires careful pairwise tuning of molecular energy levels and is proposed to be the crucial step towards the development of new, highly effective OLED systems. To date, barely few HF yellow emitters with desired narrowband emission but moderate external quantum efficiency (EQE < 20%) have been reported. This is because a systematic strategy embracing both Förster resonance energy transfer (FRET) and triplet to singlet (TTS) transition as complementary mechanisms for effective exciton transfer has not yet been proposed. Herein, we present a rational approach, which allows, through subtle structural modification, a pair of compounds built from the same donor and acceptor subunits, but with varied communication between these ambipolar fragments, to be obtained. The TADF-active dopant is based on a naphthalimide scaffold linked to the nitrogen of a carbazole moiety, which through the introduction of an additional bond leads not only to π-cloud enlargement, but also rigidifies and inhibits the rotation of the donor. This structural change prevents TADF, and guides bandgaps and excited state energies to simultaneously pursue FRET and TTS processes. New OLED devices utilizing the presented emitters show excellent external quantum efficiency (up to 27%) and a narrow full width at half maximum (40 nm), which is a consequence of very good alignment of energy levels. The presented design principles prove that only a minor structural modification is needed to obtain commercially applicable dyes for HF OLED devices.


Understanding structure–properties relationships of porphyrin linked to graphene oxide through π–π-stacking or covalent amide bonds

Anna Lewandowska-Andralojc, Ewelina Gacka, Tomasz Pedzinski, Gotard Burdzinski, Aleksandra Lindner, Jessica M O’Brien, Mathias O Senge, Aleksandra Siklitskaya, Adam Kubas, Bronislaw Marciniak, Justyna Walkowiak-Kulikowska

Two graphene oxide nanoassemblies using 5-(4-(aminophenyl)-10,15,20-triphenylporphyrin (TPPNH2) were fabricated by two synthetic methods: covalent (GO-CONHTPP) and noncovalent bonding. GO-CONHTPP was achieved through amide formation at the periphery of GO sheets and the hybrid material was fully characterized by FTIR, XPS, Raman spectroscopy, and SEM. Spectroscopic measurements together with theoretical calculations demonstrated that assembling TPPNH2 on the GO surface in DMF-H2O (1:2, v/v) via non-covalent interactions causes changes in the absorption spectra of porphyrin, as well as efficient quenching of its emission. Interestingly, covalent binding to GO does not affect notably neither the porphyrin absorption nor its fluorescence. Theoretical calculations indicates that close proximity and π–π-stacking of the porphyrin molecule with the GO sheet is possible only for the non-covalent functionalization. Femtosecond pump–probe experiments revealed that only the non-covalent assembly of TPPNH2 and GO enhances the efficiency of the photoinduced electron transfer from porphyrin to GO. In contrast to the non-covalent hybrid, the covalent GO-CONHTPP material can generate singlet oxygen with quantum yields efficiency (ΦΔ = 0.20) comparable to that of free TPPNH2 (ΦΔ = 0.26), indicating the possible use of covalent hybrid materials in photodynamic/photothermal therapy. The spectroscopic studies combined with detailed quantum-chemical analysis provide invaluable information that can guide the fabrication of hybrid materials with desired properties for specific applications.