Spremljanje poteka reakcij kataliziranih z rutenijevimi kompleksi z NMR spektroskopijo

Žust, Andraž (avtor), Pajk, Stane (mentor), Bolje, Aljoša (komentor)

Kovinski kompleksi so spojine, ki nastanejo, ko kovinski ion tvori koordinativne vezi z ligandi. Ligandi so lahko atomi, ioni ali molekule, ki kovinskemu ionu donirajo elektronske pare in tako ustvarijo koordinacijsko vez. Lastnosti teh ligandov imajo velik vpliv na lastnosti kompleksov, kar omogoča, da jih uporabljamo v različnih področjih. Imajo širok spekter uporabe v medicini, industriji, metalurgiji itd. Rutenijevi kompleksi so posebej zanimivi, ker imajo velik potencial za uporabo v medicini, predvsem kot protirakave učinkovine. Mehanizem njihovega delovanja je povezan z vezavo na DNA, kar posledično povzroči smrt rakavih celic. Poleg tega jih preučujejo tudi v kombinaciji z radioterapijo in fotodinamično terapijo. Na splošno imajo kovinski kompleksi, vključno z rutenijevimi, izjemno širok spekter uporabe. Poleg tega lahko z ligandi spreminjamo njihove lastnosti, tako da se prilagodijo različnim potrebam, kar odpira možnosti za razvoj novih zdravil in naprednih tehnologij. V okviru magistrske naloge smo raziskovali katalitične lastnosti rutenijevih kompleksov pri pretvorbi različnih reducentov oziroma antioksidantov (NADH, acetilcistein, 1-dodekantiol ipd.) v njihove reducirane oblike. Potek reakcij smo spremljali z uporabo 1H NMR spektroskopije, pri čemer smo reakcije izvajali neposredno v NMR cevkah z uporabo devteriranih topil ter zajemali spektre v različnih časovnih intervalih. Spreminjali smo reakcijske parametre, kot so čas, temperatura in v določenih primerih tudi prisotnost kisika, da bi raziskali njihov vpliv na učinkovitost katalizatorjev. V vseh primerih smo uspeli identificirati signale reaktantov in produktov, ki so bili v spektrih dovolj razločni, da smo lahko določili razmerja med reaktanti in produkti v odvisnosti od časa. Na podlagi teh podatkov smo identificirali rutenijeve komplekse z največjo katalitično učinkovitostjo. Izstopal je kompleks 1, ki je predvsem oksidacijo NADH zelo pospešil. Reakcije s tioli so bile počasnejše oz. odstotek pretvorbe manjši pri vseh kompleksih. Povišana temperatura je v vseh primerih pričakovano povečala delež pretvorbe. Je pa kataliza kompleksa 5 bila zelo odvisna od prisotnosti kisika, kar smo testirali z 4-metoksi-α-toluentiolom. Poleg tega smo spremljali nastajanje vodikovega peroksida kot potencialnega stranskega produkta. Prisotnost H2O2 v izbranih reakcijskih zmeseh smo nato preverili z ustreznim testom, vedar prisotnosti H2O2 nismo zanaznali.

• Jezik: Slovenski jezik
• Ključne besede: Kompleks, NMR, katalitska reakcija
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2025
• PID: 20.500.12556/RUL-169894
• Datum objave v RUL: 14.06.2025

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Monitoring of reactions catalyzed by ruthenium complexes by NMR spectroscopy

Izvleček

Metal complexes are compounds formed when a metal ion creates coordinate bonds with ligands. Ligands can be atoms, ions, or molecules that donate electron pairs to the metal ion, thus forming a coordination bond. The properties of these ligands greatly influence the characteristics of the complexes, enabling their use in various fields. They have a wide range of applications in medicine, industry, metallurgy, and more. Ruthenium complexes are particularly interesting due to their high potential for medical applications, especially as anticancer agents. Their mechanism of action involves binding to DNA, which subsequently leads to the death of cancer cells. Additionally, they are being studied in combination with radiotherapy and photodynamic therapy. In general, metal complexes, including those of ruthenium, have a remarkably broad range of applications. Moreover, by modifying the ligands, their properties can be adjusted to suit different needs, opening possibilities for the development of new drugs and advanced technologies. During the course of the master's thesis, we investigated the catalytic properties of ruthenium complexes for the conversion of various reductants/antioxidants (NADH, acetylcysteine, 1-dodecanethiol, etc.) into their reduced forms. The reaction progress was monitored using 1H NMR spectroscopy, with the reactions carried out in NMR tubes using deuterated solvents, and spectra recorded at various time intervals. We varied the reaction time and temperature, and in some cases, also examined the influence of oxygen. In all cases, we identified the signals of the starting compounds and products, which were sufficiently distinct in the NMR spectra to allow calculation of the ratio between reactants and products over time. This allowed us to identify the complexes that most effectively accelerated the reaction. Complex 1 stood out, as it significantly accelerated the oxidation of NADH. Reactions with thiols were slower, with the lower conversion percentage, for all complexes. As expected, elevated temperature increased the conversion rate in all cases. However, the catalysis by complex 5 was highly dependent on the presence of oxygen, which we tested using 4-methoxy-α-toluenethiol. We also examined the formation of hydrogen peroxide in the reaction mixtures, however it was not detected.

• Ključne besede: Complex, NMR, catalytic reaction