The aim of the diploma thesis was to optimize the sequential fractionation method of organic matter to be used for physico-chemical characterization of extracted fractions. Humic acid isolated from oxidized brown coal of Leonardite was used as a source matrix of organic matter. An eluotropic series was assembled and sequential fractionation was performed by extraction on a Soxhlet apparatus. The original humic acid and fractions were characterized by elemental analysis (EA) and thermogravimetric analysis (TGA), followed by Fourier transform infrared spectrometry (FTIR), molecular absorption spectrometry (UV/VIS), fluorescence spectrometry and potentiometric titration. Atomic ratios were determined from the results of the elemental analysis. From the measured UV/Vis and fluorescence excitation and emission spectra, the absorption coefficients, resp. fluorescence coefficients. Used fractionation method proved to be a suitable method for studying HA structure. A total of 62 wt. % of initial materiál was extracted, indiivdual fraction amounted from 0.36–30.92 wt. %. From the results of the structural analysis, it is clear that with increasing polarity of the organic solvent, fractions with long aliphatic chains were first isolated and their aromaticity graddualy increased. Non-polar organic solvents were suitable for the extraction of lipid-like coumpounds, while the most polar organic fractions were rich in polar groups and their structual parameters were close to the original humic acid. The fraction extracted with acetonitrile was the most unique fraction. This fraction was rich on nitrogen and amine groups and was similar to protein-like structures. In the last two fractions, extracted with alcohols, a significant bathochromic shift typical of fluorophore type V was observed. Among other things, they were also characterized by a higher content of plant carbohydrate residues.

L’aromaticité et l’antiaromaticité demeurent un sujet d’actualité au niveau fondamental puisque ces concepts permettent d’expliquer la réactivité de diverses classes de molécules. Certains composés polycycliques ayant une conjugaison π étendue, comme par exemple les tétraoxa[8]circulènes, ont des cycles aromatiques et antiaromatiques qui affectent leurs propriétés physicochimiques. Les oxacirculènes sont formés d’un anneau de quatre furanes et de quatre benzènes positionnés en alternance et créant un cœur formellement antiaromatique de cyclooctatétraène (COT). Malgré cela, ces composés démontrent une grande stabilité et peuvent servir en tant que composantes de dispositifs optoélectroniques comme des diodes électroluminescentes. Les propriétés optoélectroniques de ces composés et leur organisation moléculaire à l’état solide sont à l’origine d’un comportement unique. Le présent mémoire décrit la synthèse de tétraoxa[8]circulènes par une réaction très spéciale de cyclocondensation de 1,4-quinones catalysée par des acides, permettant d’accéder à des grandes molécules conjuguées en une étape. Les composés synthétisés ont une géométrie qui empêche leur empilement efficace et crée des vides dans la structure cristalline pouvant servir à l’inclusion de molécules invitées. En particulier, l’inclusion de C60 effectuée par cocristallisation cause l’uniformisation des longueurs des liens du cœur COT des oxacirculènes, suggérant des interactions de transfert de charge. Enfin, les propriétés optiques étudiées par spectroscopie UV-vis et par fluorescence indiquent que les oxacirculènes sont sensibles à leur environnement moléculaire et pourraient donc être utilisés comme des senseurs chimiques. / Aromaticity and antiaromaticity remain important topics of chemical research because these concepts explain the reactivity of various classes of molecules. For instance, certain polycyclic compounds with π-extended conjugation, such as tetraoxa[8]circulenes, contain both aromatic and antiaromatic rings, which affect their physicochemical properties. Oxacirculenes consist of a circular arrangement of four furan and four benzene rings positioned in an alternating fashion, thus creating a formally antiaromatic cyclooctatetraene (COT) core. Despite this, oxacirculenes exhibit great stability. They can serve as components in optoelectronic devices such as electroluminescent diodes, and their molecular organisation in the solid state can be controlled in ways that influence their properties. The present memoir describes the synthesis of tetraoxa[8]circulenes by a very special acid-catalysed cyclocondensation reaction starting from suitable 1,4-quinones, thereby allowing the preparation of large conjugated molecules in a single step. The compounds prepared have an awkward molecular structure that inhibits efficient packing and creates voids in the crystal structure, allowing the inclusion of guests. In particular, the inclusion of C60, achieved by cocrystallization, appears to create charge-transfer interactions as indicated by uniformization of bond lengths in the COT core. Optical properties studied by UV-vis spectroscopy and fluorescence show that oxacirculenes are sensitive to their local chemical environment, suggesting that they can be used as chemical sensors for the rapid detection of guests.

<p>U&nbsp; disertaciji&nbsp; je&nbsp; sprovedeno&nbsp; teorijsko&nbsp; istraživanje&nbsp; fizičko-hemijskih&nbsp; svojstava&nbsp;elektronskog podsistema molekula sumanena. Proračuni su sprovedeni u okvirima DFT i TDDFT&nbsp; teorije&nbsp; sa&nbsp; B3LYP&nbsp; funkcionalom&nbsp; i&nbsp; 6-31Gd,&nbsp; 6-31Gdp i&nbsp; 6-31++Gdp&nbsp; bazisom.&nbsp; Za&nbsp; sve&nbsp;proračune&nbsp; u&nbsp; okvirima&nbsp; navedenog&nbsp; nivoa&nbsp; teorije,&nbsp; kori&scaron;ćen&nbsp; je&nbsp; softverski&nbsp; paket&nbsp; Gaussian03.&nbsp;Ispitana&nbsp; su:&nbsp; strukturna&nbsp; i&nbsp; optička&nbsp; (zajedno&nbsp; sa&nbsp; nelinearnim)&nbsp; svojstva&nbsp; sumanena&nbsp; i&nbsp; njegovih&nbsp;derivata dobijenih modifikovanjem sa atomima bora iazota, aromatična i inverziona svojstva&nbsp;svojstva&nbsp; sumanena&nbsp; i&nbsp; njegovih&nbsp; derivata,&nbsp; adsorpciona&nbsp; svojstva&nbsp; sumanena&nbsp; prema&nbsp; molekulima&nbsp;H₂, CO, CO_2&nbsp;i NH_3&nbsp;i uticaj spolja&scaron;njeg električnog polja na svojstva sumanena.</p><p>Prema&nbsp; dobijenim&nbsp; rezultatima,&nbsp; fundamentalna&nbsp; fizičko-hemijska&nbsp; svojstva&nbsp; molekula&nbsp;<br />sumanena mogu se efikasno i fino pode&scaron;avati supstitucijom i disupstitucijom hetero-atomima&nbsp;bora&nbsp; i&nbsp; azota.&nbsp; Dubina&nbsp; i&nbsp; inverziona&nbsp; barijera&nbsp; sumanena se&nbsp; na&nbsp; ovaj&nbsp; način&nbsp; može&nbsp; menjati&nbsp; u&nbsp; oba&nbsp;smera.&nbsp; Pokazalo&nbsp; se&nbsp; da&nbsp; su&nbsp; ova&nbsp; dva&nbsp; parametra&nbsp; u&nbsp; korelaciji,&nbsp; s&nbsp; obzirom&nbsp; da inverziona&nbsp; barijera&nbsp;skoro potpuno zavisi od dubine sumanena. Slično je i sa aromatičnim svojstvima prstenova,&nbsp;koja se u zavisnosti od broja uvedenih hetero-atomamenja od aromatične preko nearomatične&nbsp;do antiaromatične prirode. Optička svojstva su, pomenutim modifikacijama, takođe značajno&nbsp;pobolj&scaron;ana: apsorpcioni pikovi kod UV/Vis spektra se pomeraju ka vidljivoj oblasti, dok je&nbsp;hiperpolarizibilnost&nbsp; sumanena&nbsp; i&nbsp; derivata&nbsp; sa&nbsp; jednim&nbsp; atomom&nbsp; bora&nbsp; vi&scaron;a&nbsp; od&nbsp; referentnog&nbsp;molekula uree, respektivno, 9 i 49 puta.</p><p>Prema dobijenim rezultatima, adsorpciona svojstva sumanena su veoma kompetitivna&nbsp;sa&nbsp; ostalim&nbsp; organskim&nbsp; molekulima&nbsp; kao&nbsp; &scaron;to&nbsp; su&nbsp; ugljenične&nbsp; nanotube&nbsp; i&nbsp; fuleren&nbsp; C₆₀,&nbsp; usled&nbsp;postojanja&nbsp; značajnog&nbsp; dipolnog&nbsp; momenta&nbsp; zbog&nbsp; specifične&nbsp; geometrije.&nbsp; Posebno&nbsp; se&nbsp; ističu&nbsp;pozitivna adsorpciona svojstva prema molekulima H_2&nbsp;<br />i CO. Dok je prvo pomenuti bitan sa&nbsp;energetskog&nbsp; aspekta,&nbsp; specifičnost&nbsp; drugog&nbsp; molekula&nbsp; se&nbsp; ogleda&nbsp; u&nbsp; činjenici&nbsp; da&nbsp; ne&nbsp; može&nbsp; biti&nbsp;adsorbovan od strane ugljeničnih nanotuba.&nbsp;</p><p>Potencijal sumanena, posebno u oblasti organske elektronike, dodatno ističu i rezultati&nbsp;ispitivanja&nbsp; uticaja&nbsp; spolja&scaron;njeg&nbsp; električnog&nbsp; polja.&nbsp; Naime,&nbsp; dobijeni&nbsp; rezultati&nbsp; ukazuju&nbsp; da&nbsp; se&nbsp;specifična&nbsp; (posebno&nbsp; adsorpciona)&nbsp; svojstva&nbsp; sumanena&nbsp; mogu&nbsp; dodatno&nbsp; pobolj&scaron;ati&nbsp; primenom&nbsp;slabog, i eksperimentalno lako ostvarljivog, električnog &nbsp;polja, jer se intenzivira razdvajanje&nbsp;naelektrisanja.</p> / <p>Theoretical&nbsp; investigation&nbsp; of&nbsp; physicochemical&nbsp; properties&nbsp; of&nbsp; electron&nbsp; subsystem&nbsp; of&nbsp;sumanene&nbsp; molecule&nbsp; has&nbsp; been&nbsp; conducted&nbsp; in&nbsp; this&nbsp; doctoral&nbsp; work.&nbsp; Calculations &nbsp;are&nbsp; performed&nbsp;within DFT and TD-DFT with B3LYP functional and 6-31Gd, 6-31Gdp i &nbsp; 6-31++Gdp basis&nbsp;sets. For all calculations, on the mentioned level of theory, Gaussian03software package was&nbsp;used.&nbsp; Investigation&nbsp; encompassed:&nbsp; structural &nbsp; and&nbsp; optical&nbsp; (including&nbsp; nonlinear)&nbsp; properties&nbsp; of&nbsp;sumanene&nbsp; and&nbsp; its&nbsp; derivatives&nbsp; obtained&nbsp; by&nbsp; modification&nbsp; with&nbsp; boron&nbsp; and&nbsp; nitrogen&nbsp; atoms,&nbsp;aromatic and bowl to bowl inversion properties of sumanene and its derivatives, adsorption&nbsp;properties of sumanene towards H₂, CO, CO_2&nbsp;i NH_3&nbsp;molecules and the influence of external&nbsp;electric field to the properties of sumanene.</p><p>According to obtained results, fundamental physicochemical properties of sumanene&nbsp;molecule could be efficiently and finely adjusted with the monosubstitution and disubstitution&nbsp;with&nbsp; hetero-atoms&nbsp; of&nbsp; boron&nbsp; and&nbsp; nitrogen.&nbsp; Bowl&nbsp; depth and&nbsp; bowl&nbsp; to&nbsp; bowl&nbsp; inversion&nbsp; barrier&nbsp;could&nbsp; be&nbsp; tuned&nbsp; in&nbsp; both&nbsp; directions.&nbsp; It&nbsp; was&nbsp; demonstrated&nbsp; that&nbsp; these&nbsp; two&nbsp; parameters&nbsp; are&nbsp;correlated, since bowl to bowl inversion barrier principally depends on the fourth power of&nbsp;bowl&nbsp; depth.&nbsp; Similar&nbsp; situation&nbsp; is&nbsp; with&nbsp; aromatic&nbsp; nature&nbsp; of&nbsp; sumanene&nbsp; rings,&nbsp; which&nbsp; change,&nbsp;depending&nbsp; on&nbsp; the&nbsp; number&nbsp; of&nbsp; introduced&nbsp; boron&nbsp; and&nbsp; nitrogen&nbsp; atoms,&nbsp; from&nbsp; aromatic&nbsp; through&nbsp;non-aromatic&nbsp; towards&nbsp; anti-aromatic&nbsp; nature.&nbsp; Thanks&nbsp; to&nbsp; mentioned&nbsp; modifications,&nbsp; optical&nbsp;properties&nbsp; are&nbsp; improved&nbsp; as&nbsp; well:&nbsp; absorption&nbsp; peaks&nbsp; in&nbsp; UV/Vis&nbsp; spectra&nbsp; shift&nbsp; towards&nbsp; visible&nbsp;area,&nbsp; while&nbsp; hyperpolarizabilities&nbsp; of&nbsp; sumanene&nbsp; and&nbsp; its&nbsp; derivative&nbsp; containing&nbsp; one&nbsp; boron&nbsp; atom&nbsp;are higher than hyperpolarizability of referent molecule of urea, respectively, 9 and 49 times.&nbsp;</p><p>Thanks&nbsp; to&nbsp; significant&nbsp; dipole&nbsp; moment&nbsp; due&nbsp; to&nbsp; the&nbsp; specific&nbsp; geometry, &nbsp;nvestigated &nbsp;adsorption properties of sumanene are very competitive to the other &nbsp;organic molecules such&nbsp;as carbon nanotubes and fullerene C₆₀. Positive adsorption properties of sumanene towards H_2&nbsp;and CO molecules are distinguished. While the H_2&nbsp;molecule is important from the energetic&nbsp;aspects, specificity of CO molecules is that it can&rsquo;t be adsorbed by carbon nanotubes.</p><p>Potential&nbsp; of&nbsp; sumanene,&nbsp; especially&nbsp; in&nbsp; the&nbsp; field&nbsp; of&nbsp; organic&nbsp; electronics,&nbsp; is &nbsp;emphasized&nbsp;through the obtained results related to the investigation of the influence of external electric&nbsp;field.&nbsp; Obtained&nbsp; results&nbsp; indicate&nbsp; that&nbsp; specific&nbsp; (especially&nbsp; adsorption)&nbsp; properties&nbsp; of&nbsp; sumanene&nbsp;could be additionally improved by application of &nbsp;weak, and experimentally easily achievable,&nbsp;external electric field, due to the higher charge separation.&nbsp;</p>

Les tétrazoles ont une place importante dans la chimie médicinale contemporaine par leurs caractéristiques spatiales et électroniques uniques. Leur haute teneur en azote leur confère également des qualités requises dans le développement de substances explosives et de haute énergie. Le développement de nouveaux outils synthétiques pour les créer prend donc ici tout son sens. Dans cet ouvrage, il est tout d’abord question d’une nouvelle méthode de synthèse qui génère des tétrazoles bicycliques en conditions douces par l’entremise d’azidonitriles aliphatiques séparés par trois ou quatre atomes de carbone (effet de proximité) et d’acides de Lewis. De plus, cette méthode de synthèse présente une réaction tandem qui génère des tétrazoles oxabicycliques 1,5-dialkylés via une cycloaddition 1,3-dipolaire diastéréosélective à partir d’azidoacétals ou d’azidocétals arborant un azoture proximal. La réaction s’effectue dans le nitrométhane de 0 °C à la température ambiante avec du TMSCN et est promue par une variété d’acides de Lewis dont le BF3OEt2. Les aspects mécanistiques de la réaction (l’ouverture des acétals, l’équilibre entre les éthers de cyanhydrine, la cycloaddition 1,3-dipolaire diastéréosélective et le réarrangement de Boyer-Schmidt-Aubé) ainsi que les paramètres réactionnels (solvants, acides de Lewis, stœchiométrie, sources de cyanure, etc.) seront en outre abordés. Ensuite, le motif de tétrazole oxabicyclique a été l’objet de diversifications, de fonctionnalisations et de transformations afin d’en valoriser l’utilité. Des réactions d’alkylations, d’azoturations radicalaires, de bêta-éliminations et de diversifications de la chaîne latérale ont été étudiées. De ces mêmes motifs de tétrazoles, la synthèse de tétrazoles azabicycliques et celle de morpholines 2,6-polysubstituées ont aussi été investiguées. La synthèse d’un sel de tétrazolium et l’alkylation de 5-tétrazolyllithiums ont aussi fait l’objet d’études préliminaires. Enfin, une étude théorique en DFT a été effectuée pour mieux comprendre l’équilibre tétrazole-azidoazométhine sur des motifs de types benzo- et pyrido- diazidodiazines parents à la 6-azidotétrazolo[5,1-a]phthalazine, un métabolite toxique du Gymnodinium breve (Ptychodiscus brevis, aussi actuellement connu sous le nom de Karenia brevis). Les aspects thermodynamiques, les états de transition, les orbitales HOMO, les cartes de potentiels d’ionisation locaux, les cartes de densité de la LUMO, les effets de solvant et certains paramètres permettant d’évaluer l’aromaticité (indices de Bird, ordres de liaison minimaux de Jug, indices HOMA et NICS) ont été considérés dans l’étude. Le constat a été que certaines des analyses théoriques peuvent constituer de bons outils prédictifs, particulièrement avec des considérations thermodynamiques, mais que cette approche a aussi ses limites qui sont principalement dues aux incertitudes inhérentes aux calculs théoriques. / Tetrazoles have an important place in contemporary medicinal chemistry due to their unique spatial and electronic characteristics. Their high nitrogen content also gives them the qualities required for the development of explosive and high energy substances. The development of new synthetic tools to create them takes here all its meaning. Therefore, in this work, a new synthesis method that generates bicyclic tetrazoles under mild conditions using aliphatic azidonitriles separated by three or four carbon atoms (proximity effect) and Lewis acids will first be discussed. In addition, a tandem reaction which generates 1,5-dialkylated oxabicyclic tetrazoles via a diastereoselective 1,3-dipolar cycloaddition from azidoacetals or azidoketals bearing a proximal azide will also be disclosed. The reaction is carried out in nitromethane at 0 °C to room temperature with TMSCN and is promoted by a variety of Lewis acids including BF3OEt2. The mechanistic aspects of the reaction (acetal opening, equilibrium between cyanohydrin ethers, diastereoselective 1,3-dipolar cycloaddition and Boyer-Schmidt-Aubé rearrangement) as well as the reaction parameters (solvents, Lewis acids, stoichiometry, cyanide sources, etc.) will be discussed. Furthermore, the oxabicyclic tetrazole unit was involved in diversifications, functionalizations and transformations to enhance its utility. Reactions of alkylations, radical azidations, beta-eliminations and diversifications of the side chain were applied. From these same tetrazole units, the synthesis of azabicyclic tetrazoles and that of 2,6-polysubstituted morpholines was also investigated. The synthesis of a tetrazolium salt and the alkylation of 5 tetrazolyllithiums were also the subject of preliminary studies. Finally, a theoretical DFT study was carried out to have a better understanding of the tetrazole-azidoazomethine equilibrium on benzo- and pyrido- diazidodiazines similar to 6 azidotetrazolo [5,1-a] phthalazine, a toxic metabolite from Gymnodinium breve (Ptychodiscus brevis, actually known as Karenia brevis). Thermodynamic aspects, transition states, HOMO orbitals, local ionization potential maps, LUMO density maps, solvent effects, and some parameters to evaluate the aromaticity (Bird index, Jug minimum bond order, HOMA index and NICS) were considered in the study. It has been noted that some of the theoretical analysis can be good predictive tools, particularly with thermodynamic considerations, but they also have their limits, which are mainly due to the uncertainties inherent in the theoretical calculations.