Synthesis and properties of novel dyes bearing azo and vinyl-group for the application in dye-sensitized solar cells

Ovom disertacijom obuhvaćena je sinteza i karakterizacija dve serije jedinjenja, kao i ispitivanje njihovih fizičko-hemijskih, fotofizičkih i elektronskih karakteristika sa mogućnošću primene u solarnim ćelijama aktiviranim bojom (engl. Dye-sensitized solar cells, DSSC). Sva jedinjenja okarakterisana su temperaturom topljenja, elementalnom analizom UV-Vis, FT-IR, ATR-FTIR, 1H i 13C NMR spektroskopijom. Prva serija je obuhvatala šest jedinjenja na bazi azo boja izvedenih iz benzoeve i cimetne kiseline, dobijene konvencijalnim postupkom diazotovanja i naknadnog diazo-kuplovanja. Pomoću UV-Vis spektroskopije ispitanisu solvatohromizam, specifične i nespecifične interakcijesa molekulima rastvarača, kao i uticaj pH vrednosti sredine na položaj tautomerne ravnoteže. Ova jedinjenja su korišćena kao aktivne komponente (fotosenzitizeri) u sastavljenim DSSC sa komercijalnim tečnim elektrolitom na bazi joda i titanijum(IV)-osidom (TiO2) kao poluprovodnom komponentom. Druga serija obuhvatala je pet jedinjenja na bazi piridinijumovih soli, dobijenih Knovenagelovom (Knoevenagel) kondenzacijom. Ova jedinjenja korišćena su kao dodatna komponenta tečnom elektrolitnom sistemu na bazi joda (LiI + I2) u 3-metoksipropionitrilu (MPN), u cilju poboljšanja fotonaponskih svojstava DSSC sa N719 bojom kao fotosenzitizerom i TiO2 kao poluprovodnikom. U cilju utvrđivanja veze između strukture jedinjenja obe serije i fotonaponskih svojstava DSSC, izvršena su kvantno-hemijska izračunavanja. Određene su vrednosti osnovnih fotonaponskih parametarasastavljanih DSSC obe serije jedinjenja, a dobijene vrednosti su upoređene sa fotonaponskim parametrima referentne DSSC koja je sadržala N719 boju, komercijalni elektrolit na bazi jod-tridodid sistemai TiO2 kao poluprovodnik. DSSC sa azo bojama su pokazale zadovoljavajuće vrednosti efikasnosti u odnosu na N719 boju, dok je primenom jedinjenja na bazi piridinijumovih soli došlo do poboljšanja fotonaponskih svojstava DSSC u poređenju sa čistim komercijalnim elektrolitom.This doctoral dissertation includes synthesis and characterization of the two series of compounds, as wellas determination of their physico-chemical, photophysical and electronic properties for potential application in Dye-sensitized solar cells, DSSC. The compounds were characterized by UV-Vis, FT-IR, ATR-FTIR, 1H and13C NMR spectroscopy. The first series included six azo compounds derived from benzioc and cinnamic acid, obtained by diazo- coupling reaction. Solvatochromic behaviour, specific and non-specific interactions with solvent molecules, as well as the impact ofpH of the solvating medium on the tautomeric equilibrium of these compounds were investigated by the means of UV-Vis spectroscopy. The first series of compounds were utilized as an active components (sensitizers) in fabricated DSSC with commercial liquid electrolyte based on iodine and titanium(IV) oxide (TiO2) as a semiconductor. The second series includes five compounds based on pyridinium salts, obtained by Knoevenagel condensation. These compounds were utilized as additional redox components to the iodine based liquid electrolyte system (LiI+I2) in 3-methoxypropionitrile (MPN) in fabricated DSSC which contained N719 dye as sensitizer and TiO2 as a semiconductor. In order to determine the correlation between molecular structure of the synthesized compounds and photovoltaic properties of DSSC, quantum-chemical calculations were conducted.The basic photovoltaic parameters of the fabricated DSSCs were determined and the obtained values were compared to the reference DSSC containingN719 dye as sensitizer along withplain commercial liquid electrolyte. The fabricated DSSCs which contained azo dyes as sensitizers showed the satisfactory values of conversion efficiency compared to the N719 dye. Also, the fabricated DSSC which utilized pyridinium salts as an additional electrolyte component enhanced the photovoltaic properties of DSSC compared to the plain liquid electrolyte

Addressing the environmental problems of wastewater: reducing the pollution while providing multifunctional wool fabrics

The reduction of water pollution represents one of the priority topics of the EU’s goal to achieve climate neutrality by 2050. Considering this, the concept of reusing the same dyebath for multiple dyeing cycles is proposed. For this purpose, two pyridinium-based azo pyridone dyes with improved solubility and affinity towards different fibers, are used for dyeing wool fabric. It is demonstrated that the dye concentration in wastewater could be reduced up to four times by recirculation of the same dyebath 5 times. The dyed fabrics obtained in each cycle are further characterized regarding color strength (K/S) and ultraviolet protection factor (UPF), while their antioxidant potential is evaluated by ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) test. The results revealed that the proposed concept could be used for obtaining multifunctional wool fabrics by following the principles of sustainable development of reducing the effluent load in wastewater

Supplementary data for article: Novkovic, L.; Trmcic, M.; Rodic, M.; Bihelovic, F.; Zlatar, M.; Matovic, R.; Saicic, R. N. Synthesis of Endoperoxides by Domino Reactions of Ketones and Molecular Oxygen. RSC Advances 2015, 5 (120), 99577–99584. https://doi.org/10.1039/c5ra13476e

Supplementary material for: [https://doi.org/10.1039/c5ra13476e]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2000

Evaluation of solvent and substituent effects on absorption spectra of spirohydantoins derived from α-tetralone

A convenient and efficient approach toward the synthesis of six 3-(4-substituted benzyl)-6,7- benzo-1,3-diazaspiro[4.5]decane-2,4-diones (1‒6) by Bucherer-Bergs reaction and further alkylation at position 3 of the hydantoin ring is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, NMR and UV–Vis spectroscopic methods. To gain an insight into interactions which the investigated spirohydantoins establish with their environment, their absorption spectra were recorded in selected solvents of different polarity and the solvent effects on the UV-Vis absorption band positions, intensity and shape, were discussed. Substiuent effects on the solvatochromism of compounds 1−6 were analyzed using the Hammett's equation. Considering the broad applications of hydantoin derivatives, as well as the fact that their relative importance may increase in the future, results obtained in this study serve as a basis for further investigations

Synthesis of endoperoxides by domino reactions of ketones and molecular oxygen

Domino reactions of ketones with molecular oxygen in the presence of potassium hydroxide and potassium t-butoxide afford cyclic hydroperoxy acetals (3,5-dihydroxy-1,2-dioxanes). Mixed endoperoxides can also be obtained in a three-component reaction of two ketones and oxygen.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3442

Evaluation of solvent and substituent effects on absorption spectra of spirohydantoins derived from alfa-tetralone

A convenient and efficient approach toward the synthesis of six 3-(4-substituted benzyl)-6,7-benzo-1,3-diazaspiro[4.5]decane-2,4-diones (1‒6) by Bucherer-Bergs reaction and further alkylation at position 3 of the hydantoin ring is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, NMR and UV–Vis spectroscopic methods. To gain an insight into interactions which the investigated spirohydantoins establish with their environment, their absorption spectra were recorded in selected solvents of different polarity and the solvent effects on the UV-Vis absorption band positions, intensity and shape, were discussed. Substiuent effects on the solvatochromism of compounds 1−6 were analyzed using the Hammett's equation. Considering the broad applications of hydantoin derivatives, as well as the fact that their relative importance may increase in the future, results obtained in this study serve as a basis for further investigations

Supplementary data for article: Novkovic, L.; Trmcic, M.; Rodic, M.; Bihelovic, F.; Zlatar, M.; Matovic, R.; Saicic, R. N. Synthesis of Endoperoxides by Domino Reactions of Ketones and Molecular Oxygen. RSC Advances 2015, 5 (120), 99577–99584. https://doi.org/10.1039/c5ra13476e

Supplementary material for: [https://doi.org/10.1039/c5ra13476e]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2000

On the azo dyes derived from benzoic and cinnamic acids used as photosensitizersin dye-sensitized solar cells

In order to get a better insight into the relationship between molecular structure and photovoltaic performance, six monoazo dye molecules containing benzoic and cinnamic acid moieties were synthesized and their photovoltaic properties were studied. Three of them have not been previously used in solar cells. Spectroscopic measurements of the investigated compounds coupled with theoretical calculations were performed. Short-circuit current density, open-circuit voltage, and fill-factor were determined. It was found that a larger amount of short-circuit current density will be generated if the HOMO-LUMO energy gap is lower, determined by the stability of the molecule and the electronic effect of the donor moiety. Among both series of synthesized dye molecules, the highest obtained values of short-circuit current density were achieved with (2-hydroxynaphthalene-1-ylazo)benzoic acid and (2-hydroxynaphthalene-1-ylazo)cinnamic acid, and thus they were regarded as promising candidates for application in dye-sensitized solar cells