Reakcije cinkovega(II) ali bakrovega(II) kinaldinata z 2-hidroksipiridinom ali 2-hidroksimetilpiridinom

Pipp, Matic Anton (author), Modec, Barbara (mentor)

V eksperimentalnem delu magistrske naloge sem bakrovo ali cinkovo izhodno spojino, [Cu(quin)$_2$(H$_2$O)] ali [Zn(quin)$_2$(H$_2$O)], reagiral z 2-hidroksipiridinom ali 2-hidroksimetilpiridinom pod različnimi pogoji. 2-hidroksipiridin v trdnem stanju obstaja v keto tavtomerni obliki, poznani pod imenom 2-piridon. Pri reakciji z bakrovo izhodno spojino se je 2-piridon vezal na bakrov(II) ion in nastala je koordinacijska spojina s sestavo [Cu(quin)$_2$(2-piridon)]. Izvedel sem številne reakcije v reakcijskem sistemu bakrove izhodne spojine in 2-hidroksimetilpiridina, vendar je bila večina teh neuspešnih, saj sem izoliral le nezreagirano izhodno spojino. Uspešna je bila le reakcija pri višji temperaturi in v prisotnosti baze, kjer so se izločili turkizni kristali nove spojine. Žal kvaliteta kristalov ni dopuščala rentgenske strukturne analize na monokristal, ki bi omogočila nedvoumno identifikacijo. Na osnovi opravljenih analiz menimo, da nova spojina vsebuje tako kinaldinat kot 2-hidroksimetilpiridinski ligand. Veliko število reakcij sem izvedel tudi v reakcijskem sistemu cinkove izhodne spojine in 2-hidroksipiridina/2-piridona, kjer mi je uspelo izolirati polimer [Zn$_{2,5}$(quin)$_4$(2-piridon)(2-Py-O)]$_n$. Na cinkov(II) ion sta v tej molekuli vezana tako 2-piridon kot 2-piridonat, anionska oblika 2-piridona, čigar prisotnost je presenetljiva, saj v reakcijski zmesi ni bila dodana močna baza, ki bi deprotonirala 2-piridon. Prav tako zanimiv je primer produkta iz reakcijskega sistema cinkove izhodne spojine in 2-hidroksimetilpiridina, [Zn(quin)(2-HmpyO)(2-HmpyOH)].Et$_2$O. Tudi v tem primeru je poleg 2-hidroksimetilpiridina, ne da bi reakcijski zmesi dodali močno bazo, na cinkov(II) ion vezana še anionska, tj. deprotonirana, oblika liganda. Produkte reakcij sem okarakteriziral z infrardečo spektroskopijo, termogravimetrično analizo in rentgensko strukturno analizo na monokristal.

• Language: Slovenian
• Keywords: koordinacijska kemija, baker(II), cink(II), 2-hidroksipiridin, 2-piridon, 2-hidroksimetilpiridin
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2024
• PID: 20.500.12556/RUL-159206
• COBISS.SI-ID: 202784259
• Publication date in RUL: 03.07.2024

Secondary language

• Language: English
• Title: Reactions of zinc(II) or copper(II) quinaldinate with 2-hydroxypyridine or 2-hydroxymethylpyridine

Abstract

In the experimental part of my master’s thesis, I reacted a copper(II) or zinc(II) starting compound, [Cu(quin)$_2$(H$_2$O)] or [Zn(quin)$_2$(H$_2$O)], with 2-hydroxypyridine or 2-hydroxymethylpyridine under different reaction conditions. In the solid state, 2-hydroxypyridine exists in keto tautomeric form, known as 2-pyridone. In the reaction with the copper starting material, 2-pyridone coordinated to copper(II) ion, forming a coordination species with the [Cu(quin)$_2$(2-pyridone)] composition. I carried out numerous reactions in the reaction system of the copper starting compound and 2-hydroxymethylpyridine, but most of these were unsuccessful, as I only isolated the unreacted starting compound. The only successful reaction occurred at a higher temperature and in the presence of a base, resulting in the formation of turquoise crystals of a new compound. Unfortunately, the quality of the crystals did not allow for single-crystal X-ray structural analysis, which would have enabled their unequivocal identification. Nevertheless, the results of the analyses suggest that the new compound contains both the quinaldinate and the 2-hydroxymethylpyridine ligands. I also carried out many reactions in the reaction system of the zinc starting material and 2-hydroxypyridine/2-pyridone, where I managed to isolate the polymer [Zn$_{2,5}$(quin)$_4$(2-piridon)(2-Py-O)]$_n$. The polymeric complex contains both 2-pyridone and 2-pyridonate, the anionic form of 2-pyridone. The presence of 2-pyridonate is surprising, as no strong base was added to the reaction mixture to deprotonate 2-pyridone. Equally interesting is the product from the reaction system of the zinc starting compound and 2-hydroxymethylpyridine, [Zn(quin)(2-HmpyO)(2-HmpyOH)].Et$_2$O. In this case as well, the anionic, deprotonated form of the ligand is bound to the zinc(II) ion, despite the absence of a strong base in the reaction mixture. The reaction products were characterized by infrared spectroscopy, thermogravimetric analysis and single-crystal X-ray structural analysis.

• Keywords: coordination chemistry, copper(II), zinc(II), 2-hydroxypyridine, 2-pyridone, 2-hydroxymethylpyridine