Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"photochromism"”.
-
Shedding Light on Phytochemical Diversity: Photochromism of chromenes isolated from Piper kelleyi
The following chapters are focused on understanding the photochromic behavior of naturally occurring chromenes and its role in the biosynthesis of a variety of natural product architectures. Ultimately, chromenes and ortho-quinonemethide derived natural products will be used to understand their …
-
Effects of High-Pressure on the Photochromism and Thermochromism of the Anils
Made available in DSpace on 2014-12-13T18:55:36Z (GMT). No. of bitstreams: 1 7804023.pdf: 5633758 bytes, checksum: 5c9741068b2c3650449a062a39cb6f14 (MD5) Previous issue date: 1977
-
Auf dem Weg zu photochromen supramolekularen Architekturen : Untersuchungen zu Synthese und Eigenschaften potentieller Bausteine
… blocks being anthracene and diarylethenes. The photochromism of the desired functionalised terpyridines was investigated; furthermore the influence of transition metal ions on the photochemical behaviour of the target molecules was studied.
-
Controlling the sense of molecular chirality with light: Toward a liquid crystal optical switch
… compounds and chirochromism, a new class of photochromism based on the photoepimerization of two diastereomers. The stereochemistry, in the former case, is controlled by the handedness of the circularly polarized light and in the latter case, controlled by the irradiating wavelength.
-
Studies in Naphthopyran chemistry
… substituted naphtho[2,1-b]pyrans showed no photochromism at 0 °C, but their derived polymers become pale yellow on irradiation. Diaryl derivatives exhibited red to brown photochromism both as monomers and polymers. Polymerisation resulted in a decreased rate of fading which is influenced by …
-
Transition metal complexes of bis(diphenylphosphino)methane, dithizone and dithiolenes: structural, spectroscopic, electrochemical and computational studies
… behaviour. None of these complexes exhibited any photochromism. X-ray crystal structures of [Pt(COD)(dptc)] and [Pt(dppf)(dptc)] were determined. Both complexes contain the dithizone ligand in a doubly deprotonated, or secondary, form. Synthetic routes to the preparation of mixed …
-
Synthesis and Optical Studies of Organoboron Compounds
… complexes. It washypothesized that the photochromism arose from radical species that form via the photooxidationof iodide and other anions by the boronium cations. Although EPR data was provided to supportthis hypothesis, the EPR data was inconsistent with that expected for the proposed …
-
Preparation and characterization of photo-, thermo-, and solvatochromic materials containing benzospiropyran
… phosphonium based system selectively exhibits photochromism only (i.e. no thermal relaxation), thus producing a potentially permanent effect or certainly a sufficiently long term effect for many applications. The control of this solute-solvent interaction by photons was coupled with an increase …
-
Studies on photochromic and potentially mesogenic mercury(II) dithizonates
… nature of the long-chain organic ligand. This photochromism was not observed in the solid state.
-
High throughput optical materials
… property. Different colours of reversible photochromism have been observed and tailored by use of different salts in the synthesis, and trends between structure and optical property have been examined.<br/>Synthesis of the anhydrous zeolite type phase K2Al2Si3O10(KCl) with edingtonite …
-
Novel Bio-Imaging Techniques Based on Molecular Switching
… sensor using protein-flexibility mediated photochromism, deep tissue imaging with super-nonlinear fluorescence microscopy, and light-driven fluorescent timer for simultaneous spatial-temporal mapping of protein dynamics in live cells. The first technique, dark state dynamics sensing and …
-
Asymmetric induction in solid state photochemistry
… in chiral crystals. Finally, solid state photochromism was discovered for some of the bridgehead-substituted dibenzobarrelene derivatives. Possible intermediates responsible for the photochromic phenomena are suggested.
-
Investigations of benzothienopyrans and related compounds
… form predominates and the compounds exhibit photochromism providing that an aryl substituent is present at C-4. Attempts to effect acid catalysed dehydration of the benzothieno[3,2-b]pyran-4-ols failed. However, treatment with N,N-dimethylcarbamyl chloride effects a novel acylative ring …
-
Photophysical transformations in molecules studied by ultrafast multi-pulse spectroscopy /
This dissertation aims at exploring excited state photoevolution of three different systems by the means of transient absorption spectroscopy. First two chapters are dedicated to the theoretical background, the description of the objects of the study and the experimental tools used. The following …
-
Molekulių fotofizikinių virsmų tyrimas ultrasparčiosios daugiaimpulsės spektroskopijos metodais /
This dissertation aims at exploring excited state photoevolution of three different systems by the means of transient absorption spectroscopy. First two chapters are dedicated to the theoretical background, the description of the objects of the study and the experimental tools used. The following …
-
Switching hybrid polymers with physically and covalently entrapped organic photochromes
The aim of this work was to test and tailor new sol gel derived hybrid polymer coatings for the incorporation of photochromic spirooxazines and chromenes. The development and optimisation of work was performed via two different routes (dye and matrix ones), that led to photochromic multi-layer …
-
Optische und strukturelle Eigenschaften von Edelmetallnanopartikeln
Noble-metal nanoparticles exhibit rich optical behavior, such as resonant light scattering and absorption and non-linear signal enhancement. This makes them attractive for a multitude of physical, chemical, and biophysical applications. For instance, recent biomedical experiments demonstrate the …