Magneto-strukturne korelacije u metalo-organskim mrežama nikla(II), bakra(II) i cirkonija(IV) istraživane spektroskopijom elektronske paramagnetske rezonancije

doctoral thesis

• Title (english): Magneto-structural correlations in metal-organic frameworks of nickel(II), copper(II) and zirconium(IV) studied by electron paramagnetic resonance spectroscopy
• Author: Senada Muratović
• Mentor: Dijana Žilić (mentor)
• Committee member: Mirta Rubčić (predsjednik povjerenstva)
• Committee member: Marijana Jurić (član povjerenstva)
• Committee member: Miroslav Požek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-07-15, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

Istražene su korelacije strukture i magnetizma odabranih metalo-organskih mreža (MOF-ova).
Opisana su magnetska svojstva Ni-MOF-74 i njegovih derivata. Rezultati pokazuju da su Ni(II)
ioni u spiralnim lancima vezani feromagnetskom (FM) interakcijom ≈ 23 K dok je interakcija
između lanaca antiferomagnetska (AFM) ≈ −4 K. Pri 16,8 K uzorak pokazuje fazni prijelaz u
AFM stanje. Gubitak vode Ni-MOF-74 značajnije ne mijenja magnetizaciju uzorka dok
amorfizacija uzrokuje spinski prijelaz Ni(II) iona iz magnetskog visokospinskog stanja S = 1 u
nemagnetsko niskospinsko stanje S = 0. Istražen je i intermedijer Ni-INT, a rezultati ukazuju
na postojanje slabe AFM interakcije u dimerima između lanaca. Opisana su i magnetska
svojstva Cu-MOF-74 te je nađeno da postoji AFM interakcija ≈ −57 K između Cu(II) iona
unutar lanca, dok je interakcija između lanaca ≈ 7,5 K. Intermedijer Cu-INT pokazuje AFM
ponašanje s nešto slabijom interakcijom JNN ≈ −4 K i JIC ≈ −1,3 K. Heterometalni MOF-74
spojevi pokazuju različita AFM ponašanja ovisno o različitim sintetskim putovima. Istraženi su
i porfirinski Zr-MOF-ovi s ionima Cu(II), Fe(III) i Mn(II) koordiniranim u porfirinske
prstenove. Za istraživanje magnetskih svojstava navedenih spojeva korištene su metode
višefrekventne elektronske paramagnetske rezonancije te magnetske susceptibilnosti.

Abstract (english)

Magneto-structural correlations of selected metal-organic frameworks (MOFs) were studied.
Magnetic properties of Ni-MOF-74 and its derivates were described. The results show that
Ni(II) ions in helical chains are coupled ferromagnetically (FM) ≈ 23 K while the interaction
between chains is antiferromagnetic (AFM) ≈ −4 K. At 16.8 K the sample shows AFM phase
transition. Dehydration of Ni-MOF-74 does not significantly influence the magnetization, while
amorphization induces spin-crossover from the magnetic high-spin state S = 1 to the nonmagnetic low-spin state S = 0. The intermediate Ni-INT was also investigated, and the results
indicate the existence of weak dimer AFM interaction between the chains. Cu-MOF-74 was
studied and it was found that there is an AFM intrachain interaction ≈ −57 K between Cu(II)
ions and the interaction between chains is ≈ 7,5 K. The intermediate Cu-INT also shows AFM
behavior with slightly weaker interaction JNN ≈ −4 K and JIC ≈ −1.3 K. Heterometalic MOF-74
compounds exhibt different AFM behaviour depending on different synthetic pathways.
Porphyrinic Zr-MOFs with Cu(II), Fe(III) and Mn(II) ions coordinated into porphyrin rings
were investigated. Multifrequency electron paramagnetic resonance and magnetic susceptibility
methods were applied to study the magnetic properties of these compounds.

• Keywords: bakar(II); cirkonij(IV); EPR sepktroskopija; magnetizam; MOF; nikal(II)
• Keywords (english): copper(II); EPR spectroscopy; magnetism; MOF; nickel(II); zirconium(IV)
• Language: croatian
• URN:NBN: urn:nbn:hr:217:624744
• Promotion: 2022
• Project: Number: IP-2018-01-3168; Title: Studija važnosti spinskih međudjelovanja kao osnova za nove pristupe u istraživanju materijala; Acronym: SPES; Leader: Marina Ilakovac-Kveder; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Project: Number: IP-2013-11-1108; Title: Karakterizacija niskotemperaturne molekulske dinamike sustava s neuređenom rešetkom metodom ESR; Title: Low-temperature molecular dynamics of systems exhibiting lattice disorder probed by ESR; Acronym: DESiRe; Leader: Marina Ilakovac-Kveder; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Project: Number: PZS-2019-02-4129; Title: Mehanokemijske i bezotopinske strategije za sintezu funkcionalnih poroznih materijala s naprednim fizičko-kemijskim i katalitičkim svojstvima; Title: Mechanochemical and solvent-free strategies towards functional porous materials with advanced physico-chemical and catalytic properties; Acronym: MECHADVANCE; Leader: Krunoslav Užarević; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: PZS
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 116 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-01-15
• Created on: 2022-09-30 11:59:15