University of Silesia in Katowice

If a chromophore molecule includes a strongly electron-rich group attached to an electron acceptor unit via a covalent bond (D–A) or π-electron bridge, photoinduced intramolecular charge transfer processes may occur in a photoexcited molecule. An introduction of an organic push-pull ligand into a transition metal coordination sphere makes the photophysics of metal complexes more complicated due to the occurrence of the intraligand charge transfer (ILCT), close in energy to the metal-to-ligand charge transfer (MLCT) one. In the case of the switch from ³MLCT to ³ILCT or formation of equilibrium between ³MLCT and ³IL/³ILCT, an enhancement of the photoluminescent properties of resulting complexes and improvement of electroluminescence performance of devices based on these compounds are expected. These metal complexes show intense photoluminescence in the visible region and have excited state lifetime, which greatly exceeds the value observed for the related ³MLCT chromophores. This approach gives the opportunity to obtain more efficient emissive materials, and thus their wider use in optoelectronics.

Within this workshop, the student will perform comprehensive photophysical studies of rhenium(I) carbonyl complex with an organic ligand of D–A or D–π–A structure. On the basis of obtained results, the student will determine the nature of the ground and excited state of the examined complex, dynamics of the formation of the lowest triplet excited state, and make a preliminary assessment of the complex in a view of its potential applications.

Detailed plan for workshop

• Determination of the solid-state structure with the use of single-crystal X-Ray analysis

The student will get familiar with the main components of Oxford Diffraction Gemini A Ultra single-crystal diffractometer and operating procedures used in X-Ray measurements. Within this part of the workshop, the student will select an X-Ray-quality crystal, carry out a pre-experiment in order to determine the unit cell parameters, diffraction symmetry and the other properties of the diffraction pattern required to calculate a suitable strategy of data collections. In the next step, the student will determine the solid-state structure of the examined Re(I) complex using Olex2 and SHELX programmes, and prepare the description of the crystal structure, including perspective views of molecular structure and crystal packing arrangement, along with tables gathering intra- and inter-molecular structural parameters (Mercury, Olex2).

• Identification of the molecular structure with the use of NMR technique

In this part of the workshop, the student will become familiar with NMR sample preparation and operating procedure with the use of TopSpin® software package. Also, the software for analysis and processing of NMR spectra and principles of the interpretation of ¹H and ¹³C NMR, and two-dimensional spectra (COSY, HMQC, HMBC, etc.) will be presented. In order to determine the ligand coordination mode and complex molecular structure, the NMR spectra will be recorded for the free ligand of D–A or D–π–A structure and its Re(I) carbonyl complex.

• Infrared and UV-Vis spectroscopy in the studies of metal coordination compounds

The student will have opportunity to record IR spectra of the free ligand of D–A or D–π–A structure and its Re(I) carbonyl complex, and then use IR spectra to determine the organic ligand coordination mode and confirm the arrangement of the carbonyl groups. The UV-Vis technique will be used to examine the impact of the intraligand charge transfer (ILCT) transition on the optical properties of Re(I) complex and determine the ground-state nature. To gain this purpose, the student will record UV-Visible spectra of the free ligand of D–A or D–π–A structure and its Re(I) carbonyl complex in solvents of different polarity, and analyse them on the basis of DFT and TD-DFT calculations.

• Stationary and time-resolved emission spectra of transition metal compounds with close in energy CT triplet excited states (³MLCT and ³ILCT)

This part of the workshop is intended to familiarize the participant with the basic principles of spectrofluorimetric techniques including: steady-state and time-resolved emission spectroscopy. The participant will have opportunity to know the construction and working of a spectrofluorometer, prepare emission and excitation spectra, measure emission decay times with the time-correlated single photon counting (TCSPC) method, determine quantum yields, and examine the impact of the environment (polarity, viscosity, temperature) on the emission spectra of metal transition complex with close in energy ILCT and MLCT triplet excited states. The student will also participate in the processing, analysis and interpretation of the photoluminescence spectra.

• fsTA spectra in the study of the equilibrium between ³ILCT and ³MLCT excited states of transition metal compounds with push-pull organic ligands

In this part of the workshop, the student will become familiar with the basics of femtosecond transient absorption spectroscopy (fsTA), configuration and working of the setup for fsTA measurements, sample preparation procedure (photostability and fluence dependence tests), collection of fsTA spectrum. The participant will also get acquainted with data processing (data preparation for analysis) and global analysis (preparation and interpretation of DAS and EAS spectra).

Wettability is one of the most widespread phenomena in nature. It is always encountered where a liquid comes into contact with a solid, which makes it one of the most important surface properties of any material and it plays a leading role in almost every field of technology. In particular, knowledge of the surface properties of porous materials is important in many industries. The wettability of porous materials with relatively simple topologies is fairly well understood, whereas for porous materials with complex and hierarchical geometries, unexpected effects are often observed, especially for phenomena occurring at the micro- and nano-scale. Moreover, the available mathematical models describing wettability do not include in their assumptions the topology of the material, i.e., the influence of complex hierarchical micro-nanoscopic structures on the effective wettability. The understanding of wettability phenomena in hierarchical micro- and nanoscopic topologies is of great importance in the study of micro- and nano-fluids and applications of micro- and nano-fluids in biotechnology and thermal energy storage technology.

1^st/2^nd day) Introduction to the School / Computer Simulations of Microporous Materials

The first two days will provide and introduction to the topic of molecular springs and nanoporous confinement. On the first day the student will be introduced to computer simulation methodology. In practice, the student will learn about, computers and clusters for high performance calculations. Then they will learn about the programs for running molecular dynamics simulations (DL_POLY, LAMMPS). This will also include a tutorial for programs for the preparation and visualization of molecular configurations (VMD, PACKMOL). This will progress towards the simulation of water-zeolite systems and then lead to the introduction for the calculation of intrusion isotherm.

The second day will present more theoretical work, to allow the student to simulate liquids, microporous and mesoporous materials. This will lead to the calculation of intrusion-extrusion isotherms of non-wetting liquids into and out of porous solids. The student will learn to choose the methods of computer simulations, the difference in molecular dynamics strategies, choice of force fields and statistical treatment of results. This will lead to the calculations of properties of the systems and a comparison with experimental results to be done in the following days.

3^rd day) Wettability Studies of Solids Surfaces

During this day, the student will learn how to prepare substrates for wettability studies and how to perform surface functionalization with silane monolayers. This will be followed by performing contact angle measurements with the use of different liquids.

4^th day) A. Surface tension measurements with pendant drop technique – practical exercises

During this day the student will learn about surface tension determination and will be able to measure the surface tension of liquids from contact angle experiments in order to calculate the critical surface tension (as a measure of wettability).

4^th day)  B. The time evolution of contact angles on the hydrophobized surfaces

5^th day) High-Pressure Calorimetry and Final Summary

This day will instruct the student on high-pressure calorimetry and will highlight the innovations and challenges with the technique. The experiment will measure the mechanical and thermal effects of a non-wetting liquid intrusion-extrusion into and from a porous environment. This day will also include an explanation of the calibration and data analysis procedure to understand the obtained thermophysical effects. This data will be interpreted using the results collected from computer simulation and surface properties measurements from the previous studies.

The current situation in the global economy requires the search for alternative energy sources and the optimization of current energy technologies, including, inter alia, searching for innovative working fluids, including heat transfer fluids (HTF). An alternative to the currently used HTFs may be systems of ionic liquids with nanoparticles (ionanofluids). Systems containing carbon nanostructures and ionic liquids are characterized by potentially superior thermophysical properties such as thermal conductivity and isobaric heat capacity compared to pure ionic liquids and nanofluids, resulting in effective, low volatility, safe, advanced heat transfer fluids in both cooling and systems solar. The aim of the research is to explain and describe the stabilization mechanism of carbon nanostructures in ionic liquids and to describe the heat transfer mechanism in ionanofluids, taking into account the structure of carbon nanostructures and ionic liquids, interactions of carbon nanostructures with the base liquid, including the surface morphology of nanostructures in ionanofluids, and temperature. The student will conduct a comprehensive study including the development of an optimal procedure for the preparation of ionanofluids, determination of the sedimentation stability of the obtained dispersions and determination of the density, isobaric heat capacity, thermal conductivity, and viscosity of selected ionanofluids. Based on the obtained results and their comparative analysis, they will determine the impact of the structure of carbon nanostructures on the thermal properties of ionanofluids in the context of their potential applications as working fluids.

Plan of the workshop:

1. Indication, based on the literature, of ionanofluid components with potentially the best properties as heat transfer systems. Formulating a research hypothesis.
2. Characteristics of an ionic liquid. Determination of the water content (drying of the ionic liquid if necessary), determination of the density and refractive index at 25 oC – liquid purity indicators. Comparison with the recommended literature data.
3. Characteristics of carbon nanoparticles. TEM and SEM analysis, size and shape.
4. Preparation of ionanofluids using a two-step method. Development of the optimal method of obtaining dispersion – selection of the sonication method, sonication time.
5. Study of sedimentation stability under various temperature conditions.
6. Determination of concentration and temperature dependence of density, isobaric heat capacity, thermal conductivity, viscosity of selected ionanofluids.
7. Processing the results, including the statistical analysis of the obtained results.
8. Based on the obtained results, their comparative analysis with commercially available heat transfer fluids and the analysis of cryo-TEM and TEM micrographs, photos obtained with an electron microscope, determination of the impact of the structure of carbon nanostructures on the thermal properties of ionanofluids in the context of their potential applications as liquid systems for heat transfer.
9. Discussion of the results – indicating the advantages and disadvantages of ionanofluids as potential heat transfer systems.

The use of near infrared spectroscopy techniques and chemometric methods for the characterization of the produced two-component mixtures in the form of powders or liquids. Getting to know the measurement possibilities of the NIR technique, the construction of the instrument (Antaris II, FT-NIR), in particular with the possibility of recording spectra of samples in the reflection mode with the use of an integrating sphere, a rotating accessory for measuring spectra for heterogeneous samples, a fiber optic probe and measurement of spectra in the transmission mode. Construction of calibration models using the principal component regression (PCR) allowing for quick estimation of vitamin C content in model mixtures of pharmaceutical products. Familiarization with good practices of building calibration models, including methods of characterizing the quality of model (fit to experimental data and prediction errors). Selected techniques of initial transformation of NIR spectra.

Preparation of phenothiazine derivatives by Sonogashira cross-coupling reaction. Purification of crude products by column chromatography. Analysis of the obtained products based on 1H NMR spectra. Preparation of solutions of the obtained compound with a precise concentration in solvents of different polarity (hexane, tetrahydrofuran, chloroform, methanol, acetonitrile). Study of the solvatochromism effect of a selected compound in various solvents by performing an absorption measurement. 

Search for new materials with desired properties and functionalities has become a major field of scientific activity with a strong financial support form industry and government. The proposed workshop will introduce students of chemistry to the fundamental problem in material characterization and design: how to connect the desired macroscopic properties to the molecular structure of matter. We will limit our interest to optical materials with a wide range of interesting properties utilizing Non Linear Optics (NLO) phenomena.

Workshop will start with a short lecture on the fundamental aspects of interaction of light with matter. The lecture will provide the necessary background of NLO pnenomena and molecular electric properties related to NLO.

During the hands-on sessions that will follow the participants will learn how to use popular tools like visualization software, software performing DFT calculations, and literature databases to obtain molecular electric properties. Analysis of the results, comparison to the reference values, and connecting them to the macroscopic characteristics will conclude the workshop

The development of medical science has made it possible to control many diseases, but there is still a need to search for new methods of therapy. A relatively new problem of modern medicine is the significant increase in bacterial and fungal infections. With the advancement of surgery and the advent of intensive care, the number and variety of these infections is increasing rapidly. Additionally, e.g. the development of chemotherapy has led to an increase in the number of immunocompromised patients. Due to the widespread use of antibiotics, often broad-spectrum antibiotics, microbes have developed a variety of drug resistance mechanisms over the years. Moreover, the number of drug-resistant strains is constantly growing. Therefore, it is necessary to search for new drugs with unique mechanisms of action that would be more effective against the pathogen and less harmful to human health. 

Quinoline derivatives have a wide range of biological activity, including have antibacterial and antifungal properties. One of the agents used in medicine based on the quinoline fragment is chlorquinaldol, which has a particularly strong effect on gram-positive bacteria and yeasts, e.g. Candida albicans. In this context, [60]fullerene derivatives are an interesting example of a biologically active carbon nanomaterial that generates the so-called reactive oxygen species – singlet oxygen and superoxide anion radical. In recent years, thanks to the intensive development of methods for structural modification of the fullerene cage, a plethora of new fullerene derivatives active against gram-positive and gram-negative pathogens have been proposed. 

The aim of the research is to combine the well-known drug – chloroquinaldol with the structure of fullerene using Bingel-Hirsch reaction. The project begins with a literature review and the development of a method of obtaining the designed chemical structure. Then the student proceeds to a multi-stage synthesis, selects the appropriate purification method and performs structural characterization of the obtained substances using techniques such as: 1H and 13C NMR, MS, IR and UV-Vis.