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Novel materials for NLO applications based on guanidine derivatives - crystal engineering and detailed characterisation
Kohúteková, Soňa ; Němec, Ivan (advisor) ; Kalbáč, Martin (referee) ; Vlčková, Blanka (referee)
Title: Novel materials for NLO applications based on guanidine derivatives - crystal engineering and detailed characterisation Author: Mgr. Soňa Kohúteková Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Ivan Němec, Ph.D. Abstract: This doctoral thesis is focused on the preparation and characterisation of new compounds for potential application in nonlinear optics (NLO). Four molecules containing guanidine fragment were chosen as the carriers of NLO properties - aminoguanidine, diaminoguanidine, N-guanidine-formamide and 1H-pyrazole-carboxamidine, according to the promising preliminary results of hyperpolarizability values obtained by quantum-chemical calculations. Experimental work was divided into two main directions of preparation of new crystalline materials - preparation of perovskite metal-organic frameworks (MOFs) and molecular crystals. In the first group of studied materials, target molecules were expected to occupy cavities of frameworks built by formate anions coordinated to metal cations. In the second group, in the molecular crystals, carriers of NLO properties were co-crystallised with selected inorganic anions to prevent the formation of centrosymmetric dimers and to influence the desired crystal packing. Prepared materials were characterised mainly by the means of...
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Surface-modified Luminescence, Surface-enhanced Raman Scattering and Plasmon Catalysed Reactivity of Ru(II) Dicarboxybipyridine Complexes Chemisorbed on Ag Nanoparticles
Žůrková, Markéta ; Vlčková, Blanka (advisor) ; Němec, Ivan (referee) ; Michl, Martin (referee)
[Ru(bpy)3]2+ (bpy = 2,2'-bipyridine) and its dicarboxybipyridine derivatives, namely [Ru(bpy)2(dcbpy)]2+ (dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) and [Ru(dcbpy)3]2+ , were employed as model molecular ions for investigation of the mechanism of surface-modified luminiscence, of light-induced surface reactivity of adsorbates in systems with Ag nanoparticles (NPs), and as prospective photoexcited reductants of Ag+ ions capable of in- situ generation of Ag NPs. The steady state and the nanosecond time resolved luminescence (namely, 3 MLCT phosphorescence) of the [Ru(bpy)2(dcbpy)]2+ chemisorbed onto the non-aggregated Ag NPs has been investigated and compared to those of the electrostatically bonded [Ru(bpy)3]2+ . The intensity decrease of the emission and the excitation spectra observed for both complexes upon their attachment to Ag NPs has been attributed to the overlap of the excitation spectra with the surface plasmon extinction (SPE) of Ag NPs. This overlap enabled energy transfer from 3 MLCT excited state of the complexes to the excited surface plasmon state of Ag NPs. Additionally, it was proved that the chemisorption of the complexes manifests itself by at least one order of magnitude shorter 3 MLCT excited state lifetime than the electrostatic interaction. Furthermore, by the newly developed...
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Perinatal brachial plexus palsy - comprehensive testing
Štěpánková, Tereza ; Vlčková, Blanka (advisor) ; Šafářová, Marcela (referee)
This thesis focuses on the comparison of the results of selected clinical trials in children with perinatal brachial plexus palsy (PBPP) in the age range of 4-6 years. The theoretical part summarizes the basic knowledge about the anatomical basis of PBPP, its types and levels of nerve injuries, the main comorbidities of PBPP, the most commonly used clinical trials, the possibilities of conservative and surgical therapy with emphasis on conservative therapy methods applied in the Czech Republic. The main goal was to determine the correlations between selected tests and verify their suitability for use in children with PBPP. Methods: A total of 14 probands with a diagnosed PBPP in the age range of 4-6 years (mean age 69.9 months; SD ± 11.6 months) were included in the study. All subjects underwent 3 clinical trials - Acvitve Movemet Scale (AMS), Brachial Plexus Outcome Measure (BPOM) and Bruininsk-Oseretsky Motor Proficiency Test - Second Edition (BOT-2), which were administered during 1-2 visits. Total and partial test results were recorded and compared in correlation analysis. Results: Based on the results of statistics a significant linear relationship between the scores of AMS and BPOM was confirmed (Pearson's r = 0.961; p < 0.001). No linear relationship between other tests or their partial...
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New pathways to plasmonic nanoparticle assembling into 2D and 3D hybrid active systems for SERS of graphene and SERS, SERRS and GERS + SERS of aromatic molecules
Gajdošová, Veronika ; Vlčková, Blanka (advisor) ; Němec, Ivan (referee) ; Michl, Martin (referee)
In the first part of the Thesis, a new type of active system for SERS and SERRS of hydrophobic molecules, namely a 3-dimensional (3D) nanosponge aggregate with incorporated hydrophobic molecules has been developed, and tested by fullerene C60 and hydrophobic free- base tetraphenylporfine (H2TPP). The SERS and SERRS (surface enhanced /resonance/ Raman scattering) limits of detection (LODs) of C60 at four excitation wavelengths spanning the visible spectral region were found to be by one order of magnitude lower than in the reference system, which mimics the previously reported ways of utilization of Ag nanosponges as substrates for SERS and SERRS. The superiority of the newly developed sample is attributed to the efficient localization of the hydrophobic molecules into hot spots in 2D fractal aggregates of Ag nanoparticles (NPs). Diprotonation of H2TPP during the procedure using HCl as the preaggregation agent has been eliminated by employment of NaCl. On the other hand, investigation of the mechanism of H2TPP protonation during the former preparation procedure opened a possibility to employ Ag nanosponge aggregate as nanoreactor. In the second part of the Thesis, 2D assemblies of AgNPs were found to be better substrates for SERS of single layer graphene (SLG) than the 3D ones. In particular, the 2D...
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Surface-enhanced Raman spectral detection of bilirubin and temporally synchronized monitoring of its photochemical transformations in selected solvents by SERS and electronic absorption spectroscopy
Hrnčířová, Jana ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
Surface-enhanced Raman scattering (SERS)-active systems based on macroscopic Ag nanosponge aggregates as well as the conditions of SERS spectral measurements were optimized for selective and sensitive detection of a biomedically important, amphiphilic bile pigment bilirubin (BR) in alkaline aqueous solutions and in its solutions in a selected water miscible solvent, namely dimethylsulfoxide (DMSO) and/or water-immiscible solvent, namely CH2Cl2. Ag nanosponges assembled by using HCl as a pre-aggregation agent were found to be the optimal SERS-active systems for a reliable detection of BR in all the above-mentioned solvents. In all cases, the protonated form of adsorbed BR has been detected upon BR incorporation into Ag nanosponges, and its marker bands have been established by SERS spectral probing at excitation wavelengths in the 445-780 nm range. The sensitivity of SERS spectral detection was evaluated in terms of the concentration values of SERS spectral detection limits (SERS LODs) of BR incorporated into Ag nanosponges. In particular, the SERS LOD for BR incorporated from its alkaline aqueous solution is 1 x 10-8 M (at 532 nm excitation), for BR incorporated from its solution in DMSO, its value is also 1 x 10-8 M (at 532 and/or 633 nm excitations), and for incorporation from the solution of BR...
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Surface-enhanced resonance Raman scattering of Zn(II) porphyrins in systems with aggregated and non-aggregated Ag nanoparticles
Spáčil, Dušan ; Vlčková, Blanka (advisor) ; Procházka, Marek (referee)
In this diploma thesis, SERRS(Surface - enhanced resonance Raman Scattering) and SERS (Surface - enhanced Raman Scattering), surface of plasmon extinction spectra and TEM images of systems with tetracationic zinc porphyrin ZnTMPyP and silver nanoparticles (Ag NPs) were studied and interpreted. The systems with isolated nanoparticles and the systems with compact aggregates were investigated. The systems with isolated nanoparticles were prepared by addition of ZnTMPyP to hydrosol of Ag NPs. NaCl was added to this system and so compact aggregates were prepared. SERRS and SERS spectra of ZnTMPyP were studied at excitation wavelengths λexc= 441.6 nm a 532 nm. Firstly, stationary systems and secondly dynamic development of hydrosol Ag NPs → Ag NPs/ ZnTMPyP → Ag NPs/ ZnTMPyP/ NaCl systems for 680 s was investigated. Time evolution of SERRS and SERS spectra were analyzed by factor analysis (FA) and time evolution of spectra extinction plasmon were measured. FA showed a strong increase of the signal of ZnTMPyP after the addition of NaCl, i.e. after conversion of isolated nanoparticles to compact aggregates. In these systems with high concentration of ZnTMPyP the increase of signal was succeeded by its decreased. With help of FA the limit of SERRS spectral detection (λexc= 441,6 nm) and limit of SERS spectral...
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Excitation wavelength-dependent Raman spectra of single-layer graphene-phtalocyanine hybrid systems
Uhlířová, Tereza ; Vlčková, Blanka (advisor) ; Němec, Ivan (referee)
A systematic chemical and spectroscopic approach to evaluation of the effect of single-layer graphene (SLG) on Raman spectra of free-base phthalocyanine (H2Pc) in glass/SLG/H2Pc hybrid systems has been developed. By a combi- nation of electronic absorption spectra, Raman spectra at five excitation wave- lengths (532, 633, 647, 785 and 830 nm) and excitation profiles of H2Pc Raman spectral bands, the constitution of the three prepared hybrid sysems has been es- tablished in the following manner: Hybrid system I comprises probably a bilayer of H2Pc molecules, system VI approximately a monolayer of H2Pc, and system X a slightly reorganized monolayer of H2Pc molecules. Micro-Raman spectral map- ping of all three hybrid systems yielded H2Pc spectral bands (together with the SLG spectral bands) at all five excitation wavelengths. By contrast, for all three HOPG/H2Pc reference systems (HOPG = highly oriented pyrolytic graphite), prepared by the same procedure as the corresponding samples, H2Pc signal was detected only at 633 and 647 nm excitations. A selective increase of normalized Raman intensities of H2Pc spectral bands for the glass/SLG/H2Pc monolayer hybrid systems at 830 nm was revealed on the basis of a mutual comparison of Raman excitation profiles of all three samples of glass/SLG/H2Pc hybrid systems....
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Study of nucleic-acid structure and interactions by resonance Raman scattering
Klener, Jakub ; Štěpánek, Josef (advisor) ; Michl, Martin (referee) ; Vlčková, Blanka (referee)
Despite the decades of intensive research, nucleic acids represent still a permanent object of structural studies. Within the framework of the doctoral work, the apparatus for measurement of UV excited resonance Raman spectra (UV RRS) was built up and optimized. A realistic and complex interpretation table was prepared based on analysis of published data and extensive series of UV RRS measurements on NA model structures, mononucleotides, and polynucleotides. The established methodology was verified when applied in several structural studies of nucleic acids, mainly the study of the influence of magnesium ions on the equilibrium between duplexes and triplexes formed by PolyA and PolyU homopolynucleotides, a study of temperature-induced structural changes in DNA double helix and DNA hairpin, and investigation of slow structural transitions of guanine quadruplexes induced by the presence of potassium ions. The results of the test measurements and the above-mentioned studies have shown that the created methodology for studying UV RRS of nucleic acids brings most of the expected benefits of the resonance excitation: the possibility of Raman scattering measurements at the same concentrations as in the case of UV absorption, high sensitivity to fine temperature-induced structural changes and good interpretability...
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