Istraživanje mehaničkog odziva kristala kadmijevih(II) halogenida s 3-nitropiridinom

master's thesis

• Title (english): Exploring mechanical responses of cadmium(II) halides with 3-nitropyridine
• Author: Ana Husinec
• Mentor: Marijana Đaković (mentor)
• Committee member: Marijana Đaković (predsjednik povjerenstva)
• Committee member: Ivan Kodrin (član povjerenstva)
• Committee member: Iva Juranović Cindrić (član povjerenstva)
• Committee member: Željka Soldin (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2020-02-20, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Kristali su se oduvijek smatrali tvrdim i krtim tvarima, ali u novije vrijeme ustanovljeno je da postoje kristali koji se djelovanjem vanjskog podražaja savijaju. U okviru ovog rada sintetizirani su koordinacijski polimeri kadmijevih(II) halogenida s 3-nitropiridinom kao ligandom; [CdCl2(3-NO2py)2]n (1), [CdBr2(3-NO2py)2]n (2) i [CdI2(3-NO2py)2]n (3). Spojevi su priređeni klasičnom otopinskom sintezom i tekućinskom difuzijom te su analizirani infracrvenom spektroskopijom, metodama termičke analize te difrakcijom rendgenskog zračenja u polikristalnom uzorku. Molekulska i kristalna struktura određene su rendgenskom strukturnom analizom metodom difrakcije rendgenskog zračenja u monokristalnom uzorku. U kristalnom pakiranju ustanovljena je važnost međumolekulskih interakcija, prvenstveno vodikovih veza, kod povezivanja polimernih lanaca u kristalnu strukturu. Igličastim kristalima spojeva 1 i 2 ispitan je mehanički odziv te je ustavljeno da daju izuzetan elastičan odziv, dok su kristali spoja 3 nefleksibilni (krti). Mehanička svojstva kristala dovedena su u korelaciju s međumolekulskim interakcijama ostvarenim u kristalnom pakiranju te je ustanovljeno da jače međumolekulske interakcije te njihova veća izotropija u smjerovima ortogonalnim na smjer izduženja kristala pogoduju elastičnoj fleksibilnosti istraženih spojeva.

Abstract (english)

Crystals are often described as brittle and inelastic solid materials that easily break under application of mechanical force. But nowadays, it is known that there are single crystals that can flex elastically or plastically when exposed to external mechanical force. This diploma thesis presents synthesis of coordination polymers of cadmium(II) halides and 3-nitropyridine; [CdCl2(3-NO2py)2]n (1), [CdBr2(3-NO2py)2]n (2) and [CdI2(3-NO2py)2]n (3). The compounds were prepared by classical solution synthesis and liquid diffusion. They were subsequently characterized by infrared spectroscopy, thermal methods and powder X-ray diffraction. Molecular and crystal structures were determined by single crystal X-ray diffraction analysis. Crystal structure analysis revealed the importance of intermolecular interactions (especially hydrogen bonds) in linking polymeric building units. Mechanical responsiveness of needle-like crystals, 1− 3, was further tested, and it was observed that needle-like single crystals of 1 and 2 are exceptionally elastic, while crystals of 3 are brittle. The correlation of supramolecular structure and observed mechanical behaviour disclosed that the more influential intermolecular interaction (and the more isotropic, in the orthogonal directions to the elongation of the crystal itself, they are) the crystals displayed the more pronounced elasticity.

• Keywords: 3-nitropiridin; fleksibilni kristali; kadmijevi(II) halogenidi; mehanički odziv
• Keywords (english): 3-nitropyridine; cadmium(II) halides; flexible crystals; mehanical response
• Language: croatian
• URN:NBN: urn:nbn:hr:217:452249
• 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: 2022-02-20
• Created on: 2020-03-19 10:18:19