Istraživanje prirode π-interakcija i multicentričnih veza između organskih radikala

doctoral thesis

• Title (english): Study of the nature of π-interactions and multicentric bonding between organic radicals
• Author: Petra Stanić
• Mentor: Krešimir Molčanov (mentor)
• Committee member: Vladimir Stilinović (predsjednik povjerenstva)
• Committee member: Jasminka Popović (član povjerenstva)
• Committee member: Marijana Jurić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2024-12-13, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

Istraživanje prirode π-interakcija u sklopu ove disertacije obuhvaća sintezu soli organskih radikala i pripravu jediničnih kristala te strukturnu analizu i analizu elektronske gustoće dobivenih spojeva. U ovom radu proučene su i opisane π-interakcije i multicentrične veze između prstena planarnih organskih radikala (palačinka-veze) u oligomerima radikal-aniona i radikal-kationa. Priroda multicentrične veze istražena je rentgenskom strukturnom analizom u jediničnim kristalima pri ekstremnim uvjetima (visokom tlaku i temperaturi) i metodama kvantne kristalografije (određivanjem gustoće naboja). Pretpostavljena fizička svojstva soli 5,6- diklor-2,3-dicijanosemikinona i 2-amino-5-metil-N-metilpiridinijevog jodida proučavana su i potvrđena mjerenjima električne vodljivosti impedancijskom spektroskopijom i magnetizacije SQUID-magnetometrom. Visoka temperatura utjecala je na rast udaljenosti između prstena radikala i rast parametara jedinične ćelije kristala. Pod utjecajem visokog tlaka smanjuju se udaljenosti između prstena radikala što ukazuje na jačanje palačinka-veze. Nadalje, topološka analiza elektronske gustoće u tri pripravljena sustava potvrdila je prisutnost multicentrične palačinka-veze kovalentnog karaktera između prstena radikal-aniona i radikal-kationa.

Abstract (english)

The study of the nature of π-interaction in this dissertation includes the synthesis of organic radical salts, preparation of single crystals, and structural analysis and analysis of charge density. In this work, π-interactions and multicentre bonds between planar organic radicals (pancake bonds) were studied and described in oligomers of radical anions and radical cations. The nature of the multicentre bond was investigated by means of X-ray structural analysis of single crystals under extreme conditions (high pressure and temperature) and quantum crystallography methods (refinement of the charge density). The assumed physical properties of 2,3-dichloro-5,6-dicyano-p-benzoquinone salt with 2-amino-5-methyl-N-methylpyridinium were confirmed by measurements of electrical conductivity by impedance spectroscopy and magnetization by SQUID. High temperature affects the growth of the distance between radical rings and growth of the cell parameters of the crystal. With high pressure distances between radical rings decrease, which indicates strengthening of the pancake bond. Topological analysis of the electron density in three prepared systems confirmed presence of multicentre pancake bonds between the rings of radical anions and radical cations and its covalent character.

• Keywords: kristalografija; multicentrična veza; π-interakcije; palačinka-veza
• Keywords (english): crystallography; multicentric bond; π-interactions; pancake bond
• Language: croatian
• URN:NBN: urn:nbn:hr:217:792272
• Promotion: 2024
• Project: Number: IP-2019-04-4674; Title: Multicentrične kovalentne veze i pi-interakcije određuju fizička svojstva kristala organskih radikala; Title: Multicentric covalent bonding and pi-interactions define physical properties of crystals of organic radicals; Acronym: MULTICENTRICBONDING; Leader: Krešimir Molčanov; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Research Projects
• Study programme: Title: Doctoral study; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica u području prirodnih znanosti (doktor/doktorica u području prirodnih znanosti)
• Type of resource: Text
• Extent: LIII, 149 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-12-19 15:21:30