A5075972230- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Porphyrin and Phthalocyanine Chemistry
- Photochemistry and Electron Transfer Studies
- Luminescence and Fluorescent Materials
- Analytical Chemistry and Sensors
- Chemotherapy-induced cardiotoxicity and mitigation
- Lanthanide and Transition Metal Complexes
- Nanoparticle-Based Drug Delivery
- Organoboron and organosilicon chemistry
- Photochromic and Fluorescence Chemistry
- Molecular Sensors and Ion Detection
- Photodynamic Therapy Research Studies
- Conducting polymers and applications
- Electron Spin Resonance Studies
- Organic Light-Emitting Diodes Research
- Characterization and Applications of Magnetic Nanoparticles
- Free Radicals and Antioxidants
- Synthesis and Biological Evaluation
- Luminescence Properties of Advanced Materials
- Phenothiazines and Benzothiazines Synthesis and Activities
- Supramolecular Chemistry and Complexes
- Crystallography and molecular interactions
- Organoselenium and organotellurium chemistry
- Electrochemical Analysis and Applications
Cardinal Stefan Wyszyński University in Warsaw
2016-2024
Polish Academy of Sciences
2016-2023
Institute of Physical Chemistry
2016-2023
University of Warsaw
2012-2013
Michigan State University
2012-2013
Federal Urdu University
2010
In the most widely used procedure for luminescence quantum yield determination, absorption and emission spectra are measured on two different instruments. This leads to errors caused by wavelength misalignment monochromator characteristics of spectrophotometer spectrofluorometer. These can be avoided using a method fluorescence determination that relies simultaneous (SAFE) measurement single commercial The method's performance is compared with standard routinely relative determination....
We have synthesized citric-acid-stabilized magnetic nanoparticles with very good magnetization behavior and relatively low contribution from shape surface anisotropies. In this work, we report also on a simple adsorption of doxorubicin onto the these nanoferrites that can provide facile preparation process for potential drug carriers. To estimate amount adsorbed doxorubicin, propose novel method utilizing ternary system determination interactions between nanoparticles. The Gibbs free...
A series of 8 luminescent borafluorene complexes were extensively studied both experimentally and theoretically in order to elucidate the effect organoboron moiety rigidification on physicochemical properties these compounds. Due spiro geometry boron atom, ligand units are perpendicularly aligned, which considerably affects flexibility molecule as well its solid-state structure. Through comparative analysis with close diphenyl analogues, we show how structural features influence thermal,...
Comparison of photostability in degassed and aerated toluene solutions is reported for 5,10,15,20-tetraphenylporphyrin, 5,10,15-tri(p-tolyl)porphyrin, their zinc analogues. After degassing, quantum yields photodegradation are higher, but the photodecomposition rates decrease. Lower stability deoxygenated due to much longer triplet lifetimes: 200-300 microseconds, compared 200-360 ns non-degassed toluene. For porphyrins, LC-MS results show that initial photoproduct contains two oxygen atoms....
Doxorubicin exhibits unusual photoreactivity in aqueous solutions. Our data show that there are two distinct photoreactive pathways for doxorubicin. One is a two-step process leads to the formation of 3-methoxysalicylic acid, stable degradation product. The other pathway photoreduction doxorubicin form corresponding dihydroquinone, which undergoes spontaneous oxidation mediated by dissolved oxygen recover with hydrogen peroxide. account known nonlinear dependence fluorescence intensity on...
Quinine is by far the most popular fluorescence quantum yield standard used nowadays. In this work, we exploit a modified version of recently developed SAFE (simultaneous absorption and emission measurement) method for investigating temperature dependence yields. The accuracy was verified using rhodamine 6G B solutions, which have well characterized dependences. Subsequently, investigated quinine solutions in 0.05 M sulfuric acid 0.1 perchloric acid. results show large This particularly...
Abstract Among seven possible nitrogen‐in constitutional isomers of porphyrin only one, porphycene, has been obtained so far in the free, unsubstituted form. Herein, synthesis another isomer, parent hemiporphycene ( HPc ), and its thorough structural, spectral, photophysical, electrochemical, theoretical characterization are reported. Most properties intermediate between those as evidenced by values inner‐cavity dimensions, orbital‐energy splittings, absorption coefficients, magnetic...
Three approaches of computational chemistry [quantum mechanics (QM) calculations, docking, and molecular dynamics (MD) simulations] were used to investigate the redox cycle bovine erythrocyte glutathione peroxidase from class 1 (GPx1, EC 1.11.1.9). The pKa calculations for two states active-site selenocysteine GPx1 (selenol, Sec45-SeH, selenenic acid, Sec45-SeOH) estimated using a bulk solvent model (B3LYP-IEFPCM B3LYP-CPCM-COSMO-RS). calculated values Sec45-SeH Sec45-SeOH corrected via...
Abstract Free base and zinc porphyrins functionalized with cyclooctatetraene (COT), a molecule known as good triplet‐state quencher, have been obtained characterized in detail by structural, spectral, photophysical techniques. Substitution COT leads to dramatic decrease of the intrinsic lifetime porphyrin triplet. As result, photostability oxygen‐free solution increases two three orders magnitude. In non‐degassed solutions, improvement is about tenfold for porphyrins, but free bases become...
The determination of luminescence quantum yields by means relative methods requires setting identical experimental conditions for both sample and reference compounds. This requirement has a critical impact on the applicability these protocols, as it does not allow precise low quantum-yield values using well-characterized high-quantum-yield standards. We show that simultaneous absorption fluorescence-emission measurement (SAFE) approach [Nawara Waluk. Anal. Chem. 2017, 89, 8650], compounds...
We have investigated the stability of doxorubicin and daunorubicin complexes with Fe3+ in aqueous solution. Doxorubicin are anthracycline chemotherapeutic agents that differ structurally by presence a hydroxymethylketone functionality versus methyl ketone moiety daunorubicin. demonstrate hydroxyl group enhances its 1:1 complexation relative to seen for utilize UV–visible absorbance, circular dichroism, fluorescence EPR spectroscopies, molecular dynamics, semiempirical calculations understand...
The photophysics and photostability of 12,13-dihydro-5H-indolo[3,2-c]acridine (IA), a rigid bifunctional indole derivative with proton donor/acceptor functionalities, can be drastically changed by the environment. formation hydrogen bonds alcohols leads to significant decrease triplet efficiency an increase photostability. photodegradation yield was found about two hundred times lower in methanol 1-propanol than n-hexane or acetonitrile. A similar effect has been reported for...
Two porphycenes, substituted at the meso positions with two and four methyl groups, respectively, reveal similar absorption spectra, but their photophysical properties are completely different. 9,20-dimethylporphycene emits fluorescence about 20% quantum yield, independent of solvent. In contrast, 9,10,19,20-tetramethylporphycene is extremely weak in nonviscous solvents, it can be recovered by placing chromophore a rigid environment. We propose model that explains these differences, based on...
We have investigated the effects of methoxy and daunosamine sugar moieties on stability anthracycline complexes with Fe3+ in aqueous solution. Idarubicin daunorubicin are structurally very similar, differing only by presence substituent at 4-position. demonstrate that group interacts sterically proximal quinone oxygen atom this interaction affects anthracycline–iron(III) complex. A similar steric effect is seen for pendent moiety. Free solution does not show any significant interactions...
Parent, unsubstituted porphycene and its two derivatives: 2,7,12,17-tetra-n-propylporphycene 2,7,12,17-tetra-t-butylporphycene were substituted at the meso position with amino nitro groups. These families of porphycenes characterized in detail respect to their spectral, photophysical, tautomeric properties. Two trans tautomers similar energies coexist ground electronic state, but only one form dominates lowest excited singlet state. Absorption, magnetic circular dichroism (MCD), emission...
We have investigated the photoreactivity of chemotherapeutic agent doxorubicin. demonstrate ability this compound to generate H2O2 catalytically as a result auto-oxidation its photoreduced form. may accumulate in toxic levels pharmaceutical preparations.
A porphycene-derived compound with a 20 π-electron skeleton has been obtained by replacing two pyrrolene units of porphycene pyridine rings. NMR, electronic absorption and MCD spectra, the lack fluorescence are typical for 4 N cyclic π electron systems. The structure differences respect to can be rationalized treating these compounds as perturbed, doubly positively charged [22]annulene [20]annulene perimeters, respectively. Even though spectroscopic photophysical criteria proposed...
Abstract The synthesis and characterization of six triarylisocyanurates, featuring 2,7‐fluorenyl or 9,10‐anthracenyl groups incorporated in their peripheral arms are reported. Photophysical studies reveal that these new octupolar derivatives more fluorescent ( Φ F ≥0.60 for all compounds except 1,3,5‐tri(9H‐fluoren‐2‐yl)‐1,3,5‐triazinane‐2,4,6‐trione 3 ) present a red‐shifted lowest absorption emission compared to known phenyl analogues comparable size. Depending on the nature terminal...
A fluorescent bis(8-oxyquinolato) diborinic complex with a central 2,2'-biphenyl backbone 1 and its octafluoro analogue 2 were synthesized to study the optical-structural relationship of sterically encumbered molecules featuring close intramolecular π-stacking interactions involving chromophore units. The crystal structure revealed unique π-stacked arrangement two pendant phenyl groups 8-oxyquinolato ligands (Q) located in inner part complex. Unlike 1, closely related features conformational...