Termodinamičko i strukturno istraživanje kompleksiranja alkalijskih kationa sa sekundarnim i tercijarnim amidnim derivatima kaliks[4]arena u nekoliko organskih otapala

master's thesis

• Title (english): Thermodynamic and structural studies on the complexation of alkali-metal cations with secondary and tertiary calix[4]arene amide derivate in several organic solvents
• Author: Antun Barišić
• Mentor: Gordan Horvat (mentor)
• Committee member: Nives Galić (predsjednik povjerenstva)
• Committee member: Vladimir Stilinović (član povjerenstva)
• Committee member: Vladislav Tomišić (član povjerenstva)
• Committee member: Gordan Horvat (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2016-06-28, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U okviru ovog rada sustavno je istražen utjecaj otapala na ravnoteže reakcija kompleksiranja sekundarnog i tercijarnog amidnog derivata kaliks[4]arena s kationima alkalijskih metala. Kompleksiranje je proučavano UV-Vis spektrometrijskim i izotermnim mikrokalorimetrijskim titracijama u više organskih otapala, N-metilformamidu (NMF), N,N-dimetilformamidu (DMF) i etanolu (EtOH). Određene su konstante stabilnosti odgovarajućih kompleksa, kao i pripadajuće termodinamičke reakcijske veličine. Na temelju određenih termodinamičkih funkcija otapanja liganda, i literaturnih termodinamičkih podataka solvatacije alkalijskih kationa, izračunane su Gibbsove energije transfera svih sudionika reakcije. Da bi se stekao detaljniji uvid u procese vezanja kationa i molekula otapala s istraživanim spojevima provedene su odgovarajuće računalne simulacije primjenom metode klasične molekulske dinamike.
Kaliksaren 𝟏 specifično veže Na+ u svim proučavanim otapalima. Kaliksaren 𝟐 u N-metilformamidu i N,N-dimetilformamidu veže sve katione alkalijskih metala, osim Cs+, dok u etanolu veže samo ione Li+ i Na+. Veća stabilnost kompleksa Na𝟐+ u odnosu na komplekse Na𝟏+, u svim proučavanim otapalima, objašnjena je preko entalpijskog doprinosa Gibbsovoj energiji kompleksiranja koji je povoljniji kod kaliksarena 𝟐. U simulacijama molekulske dinamike uočen je proces inkluzije molekula otapala kod svih nastalih kompleksa kaliksarena 𝟏 i 2.
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Abstract (english)

The effect of the solvent on the complexation reactions of a lower-rim calix[4]arene secondary and tertiary amide derivatives ( 𝟏, 𝟐 ) with alkali-metal cations was systematically investigated. Cation complexation was explored by means of UV-Vis spectrophotometric and isothermal microcalorimetric titrations in N-methylformamide (NMF), N,N-dimethylformamide (DMF), and ethanol (EtOH). The stability constants of the complexes, as well as the corresponding thermodynamic reaction quantities, were determined from the obtained experimental data. Using the experimentally determined ligand solubilities and literature data of cation solvation thermodynamics, transfer Gibbs energies of all reaction participants were calculated. To get more detailed insight into the binding of cations and solvent molecules by the investigated calix[4]arenes, molecular dynamics simulations were carried out.
Calixarene 𝟏 specifically binds Na+ in all solvents examined. In N-methylformamide and N,N-dimethylformamide calixarene 𝟐 binds all examined alkali metals, apart from Cs+, while in ethanol it only binds Li+ and Na+. Larger stability of calixarene Na𝟐+ complex then that of Na𝟏+ complex in all solvents studied, was explained by enthalpic contribution to the Gibbs energy of complexation, which is more favorable in case of complexes of ligand 𝟐. In molecular dynamics simulations the inclusion of solvent molecules was observed for all complexes of ligands 𝟏 and 2.

• Keywords: alkalijski kationi; kaliks[4]aren; kompleksiranje; mikrokalorimetrija; solvatacija; spektrofotometrija; termodinamičke veličine prijenosa; molekulska dinamika
• Keywords (english): alkali-metal cations; calix[4]arene; complexation; microcalorimetry; solvation; spectrophotometry; thermodynamic transfer quantities; molecular dynamics
• Language: croatian
• URN:NBN: urn:nbn:hr:217:425148
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2017-06-28
• Created on: 2017-03-14 13:05:21