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Complex compounds synthesis with triazole coumarine derivative
No full textDerivati kumarina su spojevi koji pripadaju klasi heterocikličkih spojeva s benzo-α-pironskom (kumarinskom) jezgrom. Zbog mnoštva derivata kumarina ukratko je opisana njihova podjela, biosinteza i sinteza u laboratoriju te različite biološke aktivnosti kao što su: antitumorska, antivirusna, protuupalna, antikoagulacijska i antioksidacijska aktivnost. Nadalje, opisani su načini stvaranja kompleksnih spojeva pomoću triazolnog prstena. U eksperimentalnom dijelu opisan je postupak priprave 6 kompleksnih spojeva s triazolnim derivatom kumarina kao ligandom i nitratnim solima prijelaznih metala (Zn, Cu, Ag, Co, Hg i Cd). Sam ligand i pripravljeni kompleksni spojevi karakterizirani su FT-IR spektroskopijom, a struktura liganda određena rentgenskom difrakcijskom analizom. Usporedbom rezultata IR spektara liganda i pripravljenih kompleksnih spojeva pretpostavljeno je da se ligand veže na metalni kation putem tion-triazolnog prstena. Kod nekih spojeva, uz navedeno povezivanje, veza se uspostavlja i putem dušikovih atoma traizolne skupine. Rezultati istraživanja upućuju na realnu mogućnost nastanka kompleksnih spojeva pripravljenih reakcijom soli prijelaznih metala i triazolnog derivata kumarina. Metodički dio rada sadrži pripremu za nastavnu jedinicu pod naslovom: Kemijska svojstva arena.Coumarin derivatives belong to the class of heterocyclic compounds with a benzo-α-pyrone (i.e. coumarin) nucleus. Due to the multitude of coumarin derivatives, the classification, biosynthesis, synthesis in the laboratory and various biological activities such as: antitumor, antiviral, anti-inflammatory, anticoagulant and antioxidant activities are briefly described. Furthermore, coordination modes of a triazole ring are described. The experimental part describes the preparation of 6 complex compounds with the coumarin triazole derivate as a ligand and transition metal nitrates (Zn, Cu, Ag, Co, Hg and Cd). The ligand itself and the prepared complex compounds were characterized by FT-IR spectroscopy and the ligand structure was determined by X-ray diffraction analysis. By comparing the results of the IR spectra of the ligand and the prepared complex compounds, we assume that the binding of ligand and metal cation occurs via thion-triazole ring. In some compounds, in addition to the above mentioned binding, the bond is also established via nitrogen atoms of the triazole group. The results of the research indicate a real possibility for the formation of complex compounds prepared by combining solutions of transition metal salts and prepared triazole coumarin derivate. The methodical part of the paper contains preparation for the teaching unit entitled: Chemical properties of arenes
Synthesis and structural characterisation of zinc complexes with dipicolinic acid hydrazide derivative
No full textPredmet istraživanja u ovom diplomskom radu je sinteza i strukturna karakterizacija cinkovih kompleksa s hidrazidnim derivatom dipikolinske kiseline. Za sintezu spojeva korišteni su cinkov(II) acetat za spojeve 1 i 2 te cinkov jodid za sintezu spoja 3. Kao ligand korišten je hidrazidni derivat dipikolinske kiseline- 6-(2-benzoil hidrazinkarbonil)pikolinska kiselina. Sintetizirana su tri kompleksna spoja 1, 2, 3. Spojevima su određene kristalne strukture metodom rentgenske strukturne analize te su karakterizirani FT-IR spektroskopijom. Ovakva vrsta spojeva pogodna je za daljnja farmaceutska i medicinska istraživanja jer su spojevi sličnih struktura i stukturnih karakteristika u prijašnjim istraživanjima pokazali dobra inzulinomimetska, anti dijabetska i anti-kancerogena svojstva.The subject of research in this diploma thesis is the synthesis and structural characterization of zinc complexes with a hydrazide derivate of dipicolinic acid. Zinc (II) acetate was used for the synthesis of complex 1 and complex 2 and zinc iodide for the synthesis of compound 3. The hydrazide derivative of dipicolinic acid - 6- (2-benzoyl hydrazinecarbonyl) picolinic acid was used as a ligand. Three complex compounds 1, 2, and 3 were synthesized. The compounds were characterized by X-ray diffraction and FT-IR spectroscopy. This type of compound is suitable for further pharmaceutical and medical research because the compounds of similar structures and structural characteristics have shown good insulin-mimetic, antidiabetic and anticancer properties in previous studies
Physiological condition of dandelion (Taraxacum officinale Weber) in urban areas assessed by biochemical parameters
No full textMaslačak (Taraxacum officinale Weber) rasprostranjena je višegodišnja biljka koja može reagirati na razna onečišćenja pa je zato dobar bioindikator. U ovom radu ispitivan je utjecaj antropogenih zagađivala na maslačak odnosno na sadržaj ukupnih topivih polifenola i askorbinske kiseline, koncentraciju proteina, klorofila i karotenoida te ukupnu antioksidativnu aktivnost. Kod uzoraka prikupljenih na prometnim lokacijama dolazi do smanjenja svih parametara u odnosu na uzorke prikupljene na lokacijama bez djelovanja prometa. Iz dobivenih rezultata možemo zaključiti da antropogena zagađivala negativno djeluju na ukupnu antioksidativnu aktivnost, pa samim time dolazi i do smanjenja sadržaja polifenola i askorbinske kiseline, koncentracije proteina, klorofila i karotenoida. Rezultat metode analize glavnih komponenata primijenjene na spektre dobivene metodom infracrvene spektroskopije s Fourierovom transformacijom (FTIR) ukazao je na razlike između uzoraka prikupljenih na prometnim i neprometnim lokacijama.Dandelion (Taraxacum officinale Weber) is a widespread perennial plant that can react to various contaminants and therefore is a good bioindicator. In this paper, the influence of anthropogenic pollutants on dandelion, including the content of total soluble polyphenols and ascorbic acid, the concentration of proteins, chlorophyll and carotenoids and the total antioxidant activity was investigated. There is a decrease in all parameters in the samples collected at the location with the traffic in comparison to those collected at the location without traffic. From the obtained results we can conclude that anthropogenic pollutants have a negative effect on the overall antioxidant activity, and there is a decrease in the content of polyphenols and ascorbic acid, the concentration of protein, chlorophyll and carotenoids. The result of the principal component analysis method applied to the spectra obtained by the Fourier transform infrared spectroscopy (FTIR) indicated differences between the samples collected at traffic and non-traffic locations
Nuclear technology and its application
No full textCilj ovog stručnog rada je obrada temeljnih procesa i njihove primjene u nuklearnoj tehnologiji. Prikazan je povijesni razvoj, od otkrića radioaktivnosti i radioaktivnih elemenata, do formacije strukture atoma kakvu danas poznajemo, te postavljanja temeljnih pretpostavki o fisijskim procesima. Kroz daljnja poglavlja detaljno su opisana dva industrijski najznačajnija nuklearna procesa, radioaktivni raspad i binarne nuklearne reakcije, te najčešće korišteni sustavi u kojima se provode ti procesi, nuklearni reaktori i čestični akceleratori. Radionuklidi nastaju kao produkti nuklearnih procesa i imaju potencijal oslobađanja određene količine energije, koja se koristi u industriji u svrhu praćenja procesa, proizvodnje električne energije i baterija, te u medicini kao način liječenja malignih nakupina.The purpose of this research paper is the explanation of fundamental processes and their application in nuclear technology. Historical development will be shown, from the discovery of radioactivity and radioactive elements to the formation of the atomic structure that we know today, also setting up the basis for fission processes. Furthermore, it will be described in detail two of the most industry significant nuclear processes, radioactive decay and binary nuclear reaction, and most widely used systems in which these processes occur: nuclear reactors and particle accelerators. Radionuclides are formed as products of nuclear processes and have the potential to release a certain amount of energy, which is used in industry to track processes, produce electricity and batteries, and in medicine as a way to cure malignant cellular formations
Development of solvent-free synthesis using planetary ball mill for CaFe systems of complex metal oxides
No full textPerovskiti su spojevi opće formule ABX3 gdje je A kation većeg ionskog promjera, B kation manjeg ionskog promjera, a X kisikov ili halogenidni anion. U ovom su radu istraživani optimalni uvjeti za sintezu trostrukog perovskita sintetskom metodom bez otapala uz pomoć planetarog kugličnog mlina. Pri tomu za kation na A položaju odabran je , B položaj dijele i u omjeru 2:1, a na anionskom položaju nalazi se kisik Parametri koji su mijenjani s ciljem poboljšanja sintetskih uvjeta su brzina vrtnje mlina (100, 150, 200, 250, 500 i 750 okr/min) te vrijeme sinteze u razmacima od 10 min do ukupno 120 min. Dobiveni uzorci su kalcinirani na različitim temperaturama te analizirani termogravimetrijski (TGA), infracrvenom spektroskopijom (FT-IR) i rentgenskom difrakcijom na prahu (PXRD). Produkt sintetiziran pri 250 okr/min i vremenu od 10 minuta imao je najveći udio ciljanog spoja, čak 92 wt %. Veličina kristalita izračunata preko Scherrerove jednadžbe je iznosila 24 nm. Ciljani je po prvi put sintetiziran u nanokristalitnom obliku.Perovskites are compounds of general formula ABX3 where A is a cation of a larger ionic diameter, B is a cation of a smaller ionic diameter and X stands for oxygen or halide anions. In this thesis optimal conditions for a synthesis of a triple perovskite using solvent-free method by means of planetary ball mill were investigated. As it can be seen, as A site cation was chosen, and share the B site in 2:1 ratio and oxygen anion was chosen for anionic site. Parameters which have been varied in the attempt to optimize synthesis conditions are rotational speed (100, 150, 200, 250, 500 and 750 rpm) and synthesis time in intervals of 10 minutes up to 120 minutes. Obtained samples were calcined at different temperatures and analyzed by thermogravimetric analysis (TGA), infrared spectroscopy (FT-IR) and powder X-ray diffraction (PXRD). Product synthesized at 250 rpm for 10 minutes contained 92 wt% of the targeted compound. Crystallite size calculated from the Scherrer equation was 24 nm. Targeted has been synthesized in nanocrystalline form for the first time
Werner complexes in experimental chemistry laboratory
No full textIzrada ovog diplomskog rada vođena je pretpostavkom slabog poznavanja Wernerove teorije i njegovih spojeva među studentima kemije. U sklopu diplomskog rada provedena je web anketa sastavljena od 15 pitanja na 100 ispitanika (studenti kemije i oni koji su završili studij unazad 5 godina) sa Sveučilišta Josipa Jurja Strossmayera u Osijeku i Sveučilišta u Zagrebu. Rezultati ankete statistički su obrađeni i pretpostavka se pokazala točnom- studenti slabo poznaju Wernerov rad, teoriju i spojeve. Čak 40% ispitanih studenada odgovorilo je da nije učilo o Werneru i njegovim spojevima. Konkretni odgovori na pitanja prepoznavanja spojeva također su ispod razine fakultetskog znanja. Kao drugi dio eksperimentalnog rada sintetizirana su 4 Wernerova kompleksna spoja prema dostupnom propisu za njihovu pripremu: trans- , cis-, i . Spojevi su okarakterizirani FT-IR analizom te su međusobno uspoređeni njihovi dobiveni spektri. Na temelju dobivenih rezultata ankete i eksperimentalnih podataka za sintezu spojeva, predložena je primjena navedena 4 spoja u eksperimentalnoj nastavi kemije u vidu izvođenja dvije vježbe u okviru 4-6 sati u dva praktikumska termina. U metodičkom djelu rada obrađena je nastavna jedinica na temu: Kompleksni spojeviThe development of this diploma thesis was guided by the assumption of poor knowledge of Werner's theory and his compounds among chemistry students. As part of the thesis, a web survey of 15 questions per 100 respondents (chemistry students and those who completed their studies 5 years ago) from the area of Josip Juraj Strossmayer University in Osijek and the University of Zagreb was conducted. The results of the survey were statistically processed and the assumption has been proved to be correct - students have little knowledge of Werner's work, theory and compounds. As many as 40% of the surveyed students answer that they did not learn about Werner and his compounds. Concrete answered to compound recognition questions are also below the level of faculty knowledge. As a second part of the experimental work, four Werner complex compounds were synthesized according to the available regulation for their preparation: trans- , cis- , and . The compounds were characterized by FT-IR analysis and their obtained spectra were compared to each other. Based on the obtained survey results and experimental data for the synthesis of compounds, it is proposed to apply these four compounds in the experimental teaching of chemistry in the form of performing two exercises within 4-6 hours in two practicum terms. In the methodical part of this diploma thesis is the teaching unit: Complex compound
Optimization of hydrothermal method towards synthesis of complex metal oxides containing manganese
No full textSinteza složenih metalnih oksida predstavlja veliki izazov, posebice ako se u jednom konačnom materijalu kombinira više različitih svojstava kao što je to u slučaju multiferoika. Ovim radom istraživani su optimalni uvjeti za sintezu trostrukog perovskita hidrotermalnom metodom, koji dosad nije sintetiziran na taj način, niti je poznat kao nanomaterijal. Cilj samoga rada je bio optimizirati uvjete obzirom na temperaturu tijekom reakcije, početne prekursore te puferska sredstva. Tako su sinteze provedene na 150 °C i 200 °C, tijekom 24 h, uz izmjenu manganovih prekursora, ∙ te ∙ , koristeći etanol i limunsku kiselinu kao puferska sredstva. Sintetizirani uzorci kalcinirani su na temperaturi od 950 °C te analizirani termogravimetrijski (TGA) i rentgenskom difrakcijom na prahu (PXRD). Također je elektrokemijski i spektroskopski analizirano ponašanje početnih prekursora otopljenih u vodi, nakon dodatka određene koncentracije mineralizatora NaOH. Najbolje rezultate i poklapanje rentgenskih maksimuma s referentnim dao je uzorak koji je sintetiziran pri 150 °C uz manganov prekursor ∙ te limunsku kiselinu za pufersko sredstvo.The synthesis of complex metal oxides is a great challenge especially if several different properties are combined into one final material as in the case of multiferroics. This paper investigates the optimal conditions for the synthesis of triple perovskite by the hydrothermal method, which has not been synthesized in this way so far, nor it is known as a nanomaterial. The aim of this work was to optimize the conditions with respect to the temperature during the reaction, the initial precursors and buffering agents. Thus, the syntheses were performed at 150 °C and 200 °C for 24 h with exchange of manganese precursors, ∙ and · , using ethanol and citric acid as buffering agents. The synthesized samples were calcined at 950 °C and analyzed by thermogravimetric (TGA) and powder X-ray diffraction (PXRD). The behavior of the initial precursors dissolved in water after the addition of a certain concentration of NaOH mineralizer was also analyzed electrochemically and spectroscopically. The best results and matching of XRD reflections with the reference were given by the sample synthesized at 150 °C with manganese precursor ∙ and citric acid as a buffering agent
Comparison of methods for determining mimetic activity of superoxide dismutase zinc complexes
No full textEnzim superoksid dismutaza (SOD) služi za obranu stanica protiv oksidacijskih oštećenja koja uzrokuju reaktivne kisikove vrste. SOD je metaloprotein koji pripada skupini oksidoreduktaza, a služi za regulaciju koncentracije ROS unutar organizma. S obzirom na metalne kofaktore koji su prisutni na aktivnom mjestu, postoji 4 oblika SOD: Cu,Zn-SOD, Fe-SOD, Mn-SOD i Ni-SOD. Iako je predodređen za obranu protiv ROS, enzim ima određena ograničenja te se upravo iz tog razloga koriste mimetici - sintetički spojevi koji imitiraju njegovo djelovanje. Primarno se istražuju radi terapeutske primjene za antioksidacijsko djelovanje zbog manje veličine, dužeg vremena poluživota i sličnosti u djelovanju s nativnim enzimom. Za određivanje mimetičke aktivnosti SOD cinkovih kompleksa razvijeno je nekoliko metoda. U radu su uspoređene metode za određivanje SOD mimetičke aktivnosti cinkova kompleksa . Korištene su tri neenzimatske metode od kojih se dvije temelje na alkalnom DMSO kao izvoru superoksidnih aniona, te jedna koja koristi fotoredukciju u sustavu riboflavin-metionin kako bi se generirali superoksidni anioni. Metodom 1 nije bilo moguće odrediti SOD aktivnost ispitivanog spoja, dok je Metodom 2 određena koja je iznosila 117 μM. Kod metode s fotoredukcijom riboflavina, vrijednost iznosi 228 μM iz čega se može zaključiti da je ova metoda manje osjetljiva i time manje pogodna za određivanje SOD mimetičke aktivnosti ispitivanog spoja.The enzyme superoxide dismutase (SOD) defends cells against oxidative damage caused by reactive oxygen species (ROS). SOD is a metalloprotein that belongs to the group of oxidoreductases, and serves to regulate the concentration of ROS within the organism. Considering the metal cofactors present in the active site, SOD is classified into 4 types: Cu, Zn-SOD, Fe-SOD, Mn-SOD, and Ni-SOD. Although its main role is to defend against ROS, the enzyme itself has certain limitations, therefore mimetics (synthetic compounds that mimic its action) are used as a replacement. They are primarily investigated for therapeutic purposes due to their antioxidant activity, smaller size, longer half-life and similarity in action to the native enzyme. Several methods have been developed to determine the mimetic activity of SOD zinc complexes. This thesis compares methods for determining the SOD mimetic activity of zinc complex . Three non-enzymatic methods were used, two of which are based on alkaline DMSO as a source of superoxide anions, and one which uses photoreduction of the riboflavin-methionine system to generate superoxide anions. Method 1 did not determine the SOD activity of the test compound, while Method 2 determined an of 117 μM. In the case of riboflavin photoreduction methods, the value is 228 μM, from which it can be concluded that this method is less sensitive and less suitable for determining the SOD mimetic activity of the test compound
Monitoring of selected water quality parameters of River Mura surface water
No full textRijeka Mura je najsjevernija rijeka u Republici Hrvatskoj, a izvire u Austriji. Mura protječe Slovenijom i Mađarskom, a u Hrvatskoj se uliva u Dravu. Duž toka, Mura je izližena različitim izvorima zagađenja, pa je u radu analizirana kvaliteta površinske vode rijeke Mure u Republici Hrvatskoj na temelju fizikalno-kemijskih parametara i aktualnih propisa te regulativa. Uzorci su prikupljani mjesečno u razdoblju od 13 godina (2004.-2017.), a među analiziranim parametrima su pH, kemijska potrošnja kisika (KPK-Mn), biokemijska potrošnja kisika (), dušikovi spojevi (nitrati, ukupni dušik) i spojevi fosfora (ortofosfati, ukupni fosfor). Dobiveni rezultati upućuju na dobru do vrlo dobru kvalitetu vode ovisno o parametru i godini. Monitoring kakvoće površinske vode potrebno je nastaviti kako bi se pratilo stanje vode i primjena mjera zaštite voda od zagađenja. U radu je prikazan metodički dio za nastavnu jedinicu "Voda" za 7. razred osnovne škole s ciljem upoznavanja važnosti vode za život, njenim sastavom, zagađenjem te potrebe za očuvanje okoliša.Mura River is Croatia's most northern river and it originates in Austria. It flows through Slovenia and Hungary, and in Croatia it flows into the Drava River. Along its course, Mura River is exposed to various sources of pollution so this thesis gives an overview and an assessment of water quality of Mura River, based on the analysis of water physico-chemical parameters according to the national laws and regulations. Water samples were collected monthly over the period of 13 years (2004-2017). Analyzed parameters included pH, chemical oxygen demand (COD-Mn), five-day biochemical oxygen demand (), nitrogen (nitrates, total nitrogen) and phosphorus compounds (orthophosphates, total phosphorus). The obtained results indicate good or very good water quality depending on the parameter and year. Further monitoring is necessary in order to ensure adequate implementation of measures for water quality protection. Also, the thesis contains a methodical part regarding class unit "Water" for the 7th grade of elementary school. The aim of the lecture is to analyze educational problems and show the composition of water, its importance in life processes, problems related to water pollution and take care about the environment
Optimization of mechanochemical synthesis of metal-organic frameworks
No full textPlanetarni kuglični mlin jedan je od najčešćih uređaja za mehanokemijku sintezu. Kompleksan način gibanja, koji nalikuje gibanju planeta, osigurava efektivan prijenos energije na reaktante. Energija se prenosi putem sudara kuglica, bez dodatnog zagrijavanja smjese. Metaloorganske mreže sastoje se od metalnih kationa i organskih liganada. Upotrebom različitih liganada, kationa i promjenom uvjeta moguće je dobiti široki spektar poroznih spojeva. Balans poroznosti i kristaliničnosti čini ove materijale generalno boljima od zeolita i sličnih poroznih materijala. MOF-5 je metaloorganska mreža sastavljena od klastera i 1,4-benzendikarboksilata. Stabilan je na temperaturi do 550 °C. Struktura mu može biti kubična ili tetragonalna, ovisno o metodi sinteze. Uglavnom se koristi za skladištenje vodika. Adsorpcijski kapacitet MOF-5 za vodik nije velik, ali raste ako prilikom sinteze materijala nije prisutan zrak. FTIR spektri MOF-5, sintetiziranog mehanokemijski, pokazuju male varijacije pri višim brzinama. Iz toga se može zaključiti da je dovoljna umjerena brzina (500 rpm) za sintezu ovog spoja.The planetary ball mill is one of the most common devices for mechanochemical synthesis. The complex mode of motion, which resembles the motion of planets, ensures the efficient transfer of energy to the reactants. Energy is transmitted through the beads, without additional heating of the mixture. Metal-organic frameworks consists of metal cations and organic ligands. By using different ligands, cations, and changing conditions it is possible to obtain a wide range of porous compounds. The balance of porosity and crystallinity makes these materials generally better than zeolites and similar porous materials. MOF-5 is a metal-organic framework consisting of clusters and 1,4-benzenedicarboxylates. It is stable at temperatures up to 550 °C. Its structure can be cubic or tetragonal, depending on the method of synthesis. It is mainly used for hydrogen storage. The adsorption capacity of MOF-5 for hydrogen is not high, but it increases if no air is present during synthesis. FTIR spectra of MOF-5, that is synthesised mechanochemicly, shows small variations at higher velocities. From this, it can be concluded that the moderate velocity (500 rpm) is sufficient for the synthesis of this compound