Termodinamičko i strukturno istraživanje kompleksiranja ciklopentafenilalanina s anionima u otopini

master's thesis

• Title (english): Thermodynamic and structural studies on the complexation of cyclopentaphenylalanine with anions in solution
• Author: Ivan Petters
• Mentor: Gordan Horvat (mentor)
• Committee member: Gordan Horvat (predsjednik povjerenstva)
• Committee member: Aleksandra Maršavelski (član povjerenstva)
• Committee member: Vladimir Stilinović (član povjerenstva)
• Committee member: Tomislav Jednačak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U okviru ovog rada istražen je kompleksacijski afinitet ciklopentafenilala (L) s halogenidnim,
tiocijanatnim i oksoanionima u acetonitrilu, metanolu i dimetil-sulfoksidu. Konstante
stabilnosti navedenih kompleksa određene su fluorimetrijskim, spektrofotometrijskim,
1H
NMR i mikrokalorimetrijskim titracijama. Za detaljan uvid u strukture nastalih kompleksa
receptor-anion te veznog mjesta liganda korištena je računalna metoda klasične molekulske
dinamike (MD). U acetonitrilu su provedene i titracije spektroskopijom cirkularnog dikroizma
(CD). CD spektri kompleksa određeni su i računski iz struktura dobivenih MD simulacijama i
kvalitativno slažu s eksperimentom. Rezultati 1H NMR titracija i MD simulacija ukazuju na to
da se koordinacija aniona odvija preko amidnih protona ciklopeptida. Stehiometrija skoro svih
nastalih kompleksa je 1:1 (receptor:anion) s iznimkom dihidrogen fosfata gdje je u
acetonitrilu uočeno vezanje dimera dihidrogen fosfata. Afinitet ciklopeptidnog receptora
koreliran je sa strukturom anionske koordinacijske sfere te sa solvatacijskim svojstvima
promatranih otapala.

Abstract (english)

For the purpose of this thesis, the complexation affinities of cyclopentaphenylalanine (L)
towards halide, thiocyanate and oxoanions in acetonitrile, methanol and dimethylsulfoxide
were investigated. The binding affinities of mentioned complexes were determined by means
of fluorimetric, spectrophotometric, 1H NMR and microcalorimetric titrations. For a detailed
structural overview of receptor-anion complexes, as well as the anion binding site of ligand L,
classical molecular dynamics (MD) simulations were performed. Circular dichroism (CD)
titrations were carried out in acetonitrile. The CD spectra were also calculated from the
structures obtained by MD simulations and were qualitatively in agreement with the
experiment. The results of 1H NMR and MD studies indicated that the bound anions were
coordinated by the amide groups of cyclopeptide. The stoichiometry of almost all complexes
was 1:1 (receptor:anion), with the exception of dihydrogen phosphate where the binding of
dihydrogen phosphate dimer was observed in acetonitrile. The affinity of the cyclopeptide
receptor was correlated with the structure of anion coordination sphere as well as with the
solvation properties of the examined solvents.

• Keywords: ciklopeptidi; vezanje aniona; fluorimetrija; cirkularni dikroizam; UV-Vis spektrofotometrija; 1H NMR; MD simulacije; utjecaj otapala
• Keywords (english): Cyclopeptide; Anion binding; Fluorimetry; Circular dichroism; UV-Vis spectrometry; 1H NMR; MD simulations; Solvent effect
• Language: croatian
• URN:NBN: urn:nbn:hr:217:702586
• Project: Number: IP-2019-04-9560; Title: Koordinacijske reakcije makrocikličkih liganada u otopini; Title: Coordination Reactions of Macrocyclic Ligands in Solution; Acronym: MacroSol; Leader: Vladislav Tomišić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• 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
• Created on: 2022-09-28 10:07:44