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Interzeolite conversion is a zeolite synthesis avenue that uses a crystalline zeolite material as a source of T atoms to obtain another crystalline zeolite [1, 2]. It is a principal method for preparation of certain zeolites such as CHA-type materials [3, 4]. The benefits of this approach with respect to conventional direct synthesis route from chemicals via amorphous precursors are reduced syntheses periods (enhanced crystallization rate), high yields, and the use of alternative organic structure directing agents (OSDAs) [5]. Besides, interzeolite conversion may provide materials of distinct features compared to the ones from classical synthesis mixtures thus expanding the opportunities of designing zeolite materials with target properties [2, 6]. Taking all this into consideration, interzeolite conversion is regarded as synthesis route with high potential in green chemistry era. Recently was reported mechanochemically induced interzeolite conversion [7] that may improve zeolite production in terms of chemicals used, their quantity, yielded waste and energy consumption as well as costs and thus represents an advancement in environment protection. Mechanochemical methods have gained a lot of attention in the past several years, especially as a possible solution for various drawbacks of solution-based syntheses and processes [8]. The present work brings the previous results to potentially even more environment-friendly level – naturally occurring zeolite mineral clinoptilolite (HEU-type) was used as source material in zeolite synthesis. Clinoptilolite was milled with NaOH, KOH, CsOH and tetramethylammonium hydroxide (TMAOH) with a small amount of added water at 110 °C. The reactions were overseen in situ by synchrotron XRD. In the presence of TMAOH any change takes place and the starting material remains intact for 90 minutes. With NaOH and KOH are observed peaks of the clinoptilolite, but they appear and disappear which may be due to experimental issues. The interzeolite conversion occurred promptly in the milled system using CsOH as mineralizer, yielding ANA after 30 minutes suggesting that the interzeolite conversion is quicker in the presence of CsOH than NaOH, KOH and TMAOH. It is expected that the findings reported here will provide guidelines for designing and conducting further ball milling experiments to achieve even more environment-friendly process of zeolite synthesis.

Inorganic medicinal chemistry is a rapidly growing research area focused on the use of metal- containing drugs, inhibitors of metalloenzymes and metal complexes in the diagnosis of tumor and neurological diseases. The biological action of metal complexes is governed by catalytic activity, redox and photochemical properties and equilibrium reactions of a ligand and a metal ion that lead to the formation of biologically active species.1 Due to its stability, electrochemical properties and low toxicity, ferrocene is an important metallocene in the design of new chemotherapeutics.2 The introduction of ferrocene into biologically active compounds is carried out to increase the interaction of the drug with the receptor, which can be achieved by bioisosteric replacement of a phenyl group with ferrocene. The ferrocene subunit forms stronger interactions with the hydrophobic pocket of the biological target.3 Our recent work is focused on the synthesis and biological evaluation of heterobimetallic ferrocene complexes and their biological activity.4 Ferrocene derivatives of dipyridylamine and their Zn(II) and Cu(II) complexes were synthesized and their cytotoxic effect was explored on tumor cells. The Cu(II) complex with methylmethine linker between ferrocene and dipyridylamine showed the most prominent and selective cytotoxicity. Cell cycle analysis by flow cytometry revealed that the mechanism of cytotoxicity is dependent on the identity of the metal ion.

The stereochemistry of flexible tridentate ligands influences many important properties like stability and reactivity in a chemical or biological environment. Metal coordination with bis-1, 2, 3- triazole ligands is an unexplored area of research in comparison to the structurally related dipicolylamine derivatives. In this work, bis-1, 2, 3-triazole derivatives with unsubstituted N- and O-central donor atoms were prepared using click chemistry by the reaction of aromatic azides with dipropargylamine and dipropargyl ether, respectively. Coordination of transition metals was studied in solution by NMR and UV-Vis spectrometry, along with characterisation in solid-state by single- crystal X-ray crystallography. Our research has shown that these types of ligands prefer formation of ML2 metal complexes. Study of the stereochemical preferences is currently underway as these ligands are able to form cis-, trans-fac or mer-isomers.

Bis-tridentatni metalni kompleksi fleksibilnih liganada [M(A-X-A)2] strukture imaju tri različita geometrijska izomera: mer, trans-fac i cis-fac. [1] Na stabilnost pojedinih izomera utječe niz faktora poput elektronskih i steričkih svojstava liganda, vrsta metalnog iona, mogućnost ostvarivanja nekovalentnih interakcija, vrsta protuiona i drugih. Utjecaji pojedinih faktora na nastanak određenog izomera ML2 kompleksa do danas nisu detaljno istraženi, a razumijevanje tih faktora nam omogućuje dizajn novih kompleksnih spojeva željene geometrije i svojstava. [2, 3] U ovom radu pripravljeni su derivati tridentatnih liganada bis(piridin-2-ilmetil)amina (bpa) i 2, 2'- iminodiacetamida (imda) te njihovi kompleksi s različitim solima Zn(II), Cu(II), Ni(II) i Co(II). Središnji donorski atomi liganada bili su kisik ili sumpor, odnosno -NPh- ili -PPh- skupine. Strukture spojeva u čvrstom stanju karakterizirane su difrakcijom rendgenskih zraka na jediničnom kristalu, a strukture u otopini spektroskopijom NMR. Stehiometrija i stereokemija kompleksa te moguće konformacije supstituenata u ovim sustavima modelirane su pomoću DFT računa kako bi se odredila njihova međusobna relativna stabilnost. Usporedbom eksperimentalnih podataka i DFT računa uočene su preference pojedinih središnjih atoma ka određenim stereoizomerima ML2 kompleksa. Jedan od ciljeva ovog istraživanja bio je odrediti koji čimbenici uzrokuju nastanak cis-fac izomera, koji bi se u slučaju dušika ili fosfora kao središnjeg donorskog atoma, mogli upotrijebiti za dizajn novih selektivnih katalizatora.

Bis-tridentate metal complexes of flexible ligands with [M(A-X-A)2] structure can form three different geometric isomers: mer, trans-fac and cis-fac[1]. Stability of an isomer is influenced by many factors such as electronic and steric properties of the coordinating ligand, type of metal ion, possibility of forming non-covalent interactions, type of anion present and others. The influences of such factors on a formation of a specific isomer of ML2 complex are not fully described. Understanding the isomer preference in said systems is an important starting point in development of new complex compounds with desired form and properties [2, 3]. In this work, derivatives of tridentate ligands bis(2-pyridine-2-ylmethyl)amine (bpa) and 2, 2’- iminodiacetamide (imda) were prepared and their corresponding complexes with different salts of Zn(II), Cu(II), Ni(II) and Co(II). For the central donor atoms oxygen and sulfur were chosen and in the case of nitrogen and phosphorous -NPh- and - PPh- functional groups. The solid-state structures of prepared complexes were characterized by single-crystal X-ray diffraction, while the structures in solution were studied by NMR spectroscopy. The stoichiometry and the stereochemistry of these complexes, together with possible conformations of their substituents, were studied using the (SMD)/M05-2X/6-31+G(d) DTF computational approach to determine their relative stability to each other. Experimental and computational results were compared and preferences of some central donor atoms to form specific isomers of ML2 complexes were observed. One of our goals was to determine which factors lead to formation of cis-fac isomers, which could be in the case of nitrogen or phosphorous as central atoms used in the development of new asymmetric catalysts.

Asymmetric tridentate ligands L (L= acetamide- pyridine) of the type A-B-C, (Figure 1a) enrich the isomerism of bis-tridentate A-B-A ligands [1] to six possible isomers of [M(A-B-C)2] complexes (M=metal, Figure 1b). Ligand L and metal complex [Zn(L)2](BF4)2 have been synthesized and characterized by solution-state NMR (1H and 13C). It is generally known that ligand coordination to the metal atom destroys NMR magnetic equivalences of nuclei near the metal atom, therefore increasing the number of signals in NMR spectra and appearance of hidden J-couplings (Figure 1c). Magnetic equivalences originate from fast nuclei- exchange processes (faster than NMR timescale), due to rotational/inversion motions of molecules in solution. Therefore, the DFT simulation of solution-state NMR spectra is a computational challenge and only recently satisfactory procedures have been suggested [2]. Herein, the conformational space of ligand L and complex [Zn(L)2]2+ has been explored by the CREST program [3]. Ensembles of conformations were optimized on the DFT theory level and free energies were calculated. For conformers with Boltzmann population > 1% the NMR parameters (shifts and J- couplings) have been calculated by the DFT/GIAO theory using the ORCA program [4]. Finally, from differences between measured and calculated NMR data, the most probable isomer of [Zn(L)2]2+ complex in solution is obtained.

Bis-tridentate metal complexes of flexible ligands with [M(A-X-A)2] structure can form three different geometric isomers: mer, trans-fac and cis-fac. Many factors influence the stability of a certain isomer. Important factors to consider are electronic and steric properties of the coordinating ligand, type of central metal ion and counter-ion present, possibilities of forming non-covalent interactions and others. Understanding of the isomer preferences in hereby described systems would give us a head start in the development of new coordination compounds with desired form and properties. Derivatives of tridentate ligands bis(pyridine-2-ylmethyl)amine (bpa) and 2, 2’-iminodiacetamide (imda) were prepared in this work, as well as their corresponding complexes with different Zn(II), Cu(II), Ni(II) and Co(II) salts (Figure 1). Oxygen and sulfur, as well as -NH-, -NPh-, -PH- and -PPhfunctional groups were chosen to occupy a central position in the ligand structure. The stoichiometry and the stereochemistry of these complexes, together with possible conformations of their substituents, were studied using the DTF computational approach to determine their relative stability in solution. The systems in solution were studied by NMR and UV-Vis spectroscopy, while the solid-state structures of prepared complexes, characterized by single-crystal X-ray diffraction, gave us an insight of the isomerism in the solid-state. Experimental and computational results were discussed and preferences of some central donor atoms to form certain isomers of ML2 complexes were shown. One of our goals was to determine which factors lead to formation of cis-fac isomers, which could, in the case of nitrogen or phosphorous as central atoms, be used in the development of new type of selective catalysts.

U okviru ove disertacije proučavana je stereokemija kompleksa 2,2'-iminodiacetamida i bis(piridin-2-ilmetil)amina, te je ispitan utjecaj supstituenata na ligandu, aniona, i nekovalentnih interakcija. Pripravljeni ligandi podijeljeni su u četiri skupine. Priređeno je 8 različito supstituiranih iminodiacetamidnih liganada (A) te je istražen utjecaj supstituenata na stereokemiju metalnih kompleksa. S H-supstituiranim ligandom dobivena je kristalna struktura cis-fac kompleksa, dok su s ostalim ligandima dobiveni trans-fac izomeri. S izopropil-supstituiranim bis(piridin-2-ilmetil)aminskim ligandom (B) priređeni su kompleksi koristeći Cu(II) i Zn(II) s različitim anionima. Ovisno o anionu, dobivene su kristalne strukture monomera, dimera, cis-fac-ML2 kompleksa te ciklički trimer koji veže CO2 iz zraka. Kompleksi Fe(II) s 2 cikloheksandiaminska derivata (C) ispitani su u katalitičkim reakcijama kao mimici enzima flavon sintaze. Također je priređeno 7 bis(piridin-2-ilmetil)aminskih i 5 iminodiacetamidnih liganada (D) s različitom duljinom CH2 poveznice i različitim kiralnim skupinama kako bi se istražio utjecaj strukturnih promjena na koordinacijska svojstva liganada u kompleksima Cu(II) i Zn(II). Ligandi s 3 CH2 skupine tvorili su komplekse ML2 stehiometrije, dok je kod liganada s 2 CH2 skupine došlo do koordinacije pokrajnjeg lanca i stvaranja ML kompleksa. Kompleksi ML stehiometrije pokazali su aktivnost u DNA cijepanju. In this dissertation, the stereochemistry of 2,2'-iminodiacetamide and bis(pyridin-2-ylmethyl) amine ligand complexes was studied, focusing on the influence of substituents on the ligand, anion and noncovalent interactions. The prepared ligands were divided into four groups. Eight differently substituted iminodiacetamide ligands (A) were prepared. A cis-fac crystal structure was obtained with the H-substituted ligand, while the other ligands gave trans-fac isomers. Complexes with Cu(II) and Zn(II) were prepared with a isopropyl-substituted bis(2-pyridine-2-ylmethyl)amine ligand (B). Depending on the anion, crystal structures of monomers, dimers, a cis-fac-ML2 complex and a cyclic trimer that binds CO2 from air were obtained. Fe(II) complexes with two cyclohexanediamine derivatives (C) were investigated in catalytic reactions as flavone synthase mimics. Furthermore, 7 bis(2-pyridine-2-ylmethyl)amine and 5 iminodiacetamide ligands (D) with different lengths of CH2 linkers and different chiral groups were prepared to study the influence of structural changes on the coordination properties of these ligands in Cu(II) and Zn(II) complexes. Ligands with 3 CH2 groups formed ML2 complexes, while ligands with 2 CH2 groups showed side chain coordination and formation of ML complexes. Complexes of ML stoichiometry showed DNA cleavage activity

Bis-tridentate ligand complexes can form three geometric isomers ; mer, trans-fac and cis-fac. For the synthesis of functional complexes incorporating tridentate ligands, understanding the isomer preferences is an important starting point. One way of stabilizing a particular isomer is by non-covalent interactions. In literature, such non-covalent interactions were often found with anions or as π-π interactions in ligands containing aromatic rings. In this work, complexes of tridentate bis(2- pyridine-2-ylmethyl)amine (bpa) and 2, 2'- iminodiacetamide (imda) ligands were prepared with Cu(II) and Zn(II). The ligands have chiral side chains, with amide groups that enable the formation of hydrogen bonds. The solid-state structures were characterized by single-crystal X-ray diffraction, while the structures in solution were studied by NMR, UV-Vis and CD spectroscopy. Several variations were introduced into the ligand structure, such as length of the CH2 linker, orientation of the amide group and type of chiral substituent, in order to construct a ligand suitable for the formation of secondary structures.

Coordination complexes of dipyridylamine (dpa) have shown interesting properties applicable in catalysis and material sciences as well as medicinal chemistry. Our previous study examined the properties and coordination chemistry of triazole-appended dpa derivatives. To expand the knowledge about this type of ligands, ferrocene derivatives of dpa with 1, 2, 3-triazole linker and their Cu(II) complexes were prepared. Dpa-tz ligands prefer formation of metal complexes with trans configuration, while coordination of the 1, 2, 3-triazole group depends on N-1 substitution.

Organometallic and metal-based complexes have been widely used in drug discovery and some of them have entered clinical trials for the treatment of cancer. Design of new chemotherapy agents based on metal complexes is a fast-growing research area in which the biological activity of antitumor agents is based on metal-specific modes of action.1 The ferrocene pharmacophore is often introduced into the structure of drug-like molecules and bioactive hybrids with the aim of improvement of physicochemical properties and potency. In continuation of our research on coordination of mono- and bis-1, 2, 3-triazole derivatives, 2 we have synthesized and characterised ferrocene ligands as well as their Zn(II) and Cu(II) complexes by NMR, IR and UV-Vis spectroscopy and SC- XRD. Cytotoxic activity of N-heterocyclic ferrocene derivatives and their Zn(II) and Cu(II) complexes was evaluated.

Ferrocene compounds have attracted significant interest as biologically active derivatives. Introduction of the ferrocene moiety in drug-like molecules improves the physicochemical properties and stability of drug candidates, while the transition metals coordinated to biologically active ligands participate in metal-specific processes which enhance drug delivery and biological activity. As part of our research of ferrocene derivatives and their transition metal complexes, we have prepared dipicolylamine, iminodiacetamide and bis-triazole derivatives connected to ferrocene through an ethylenediamine linker. The conjugates were used as ligands in the synthesis of Zn(II), Ni(II) and Cu(II) metal complexes. The stoichiometry and stereochemistry of the obtained complexes were examined by NMR and UV-Vis spectroscopy. We have obtained two crystal structures of metal complexes with bis-triazole ligands and one with an iminodiacetamide ligand. Investigation of antitumor activity is in progress.

Ferrocene represents a significant pharmacophore in medicinal chemistry along with its derivatives being important ligands in coordination chemistry. Click chemistry involves a set of widely applicable stereospecific reactions with high yield and without unwanted side reactions. The copper-catalysed azide–alkyne cycloaddition (CuAAC) reaction represents a simple approach to the synthesis and fine-tuning the properties of 1, 2, 3-triazole ligands. Our goal was to prepare novel mono- and bis- ferrocenyl derivatives connected to an aromatic amine through a 1, 2, 3- triazolyl linker. Conjugates of ferrocene and heterocycles were prepared by CuAAC reactions of propargylated aromatic amines and ferrocene azides. Conjugates of ferrocene and heterocycles were used as ligands in the synthesis of Zn(II) and Cu(II) metal complexes and the stoichiometry and stereochemistry of the obtained complexes was examined. The structures of the newly synthesized derivatives were confirmed by 1H and 13C NMR spectroscopy. The spectroscopic properties of the obtained complexes were investigated by NMR, UV- Vis and IR spectroscopy. Crystal structures of several Cu(II) complexes containing mono- and bis- ferrocenyl ligands were determined by single- crystal X-ray diffraction.

The diketopiperazines have been steadily attracting researchers’ attention in pharmaceutical chemistry due to their potential biological effects. Electrospray ionization mass spectrometry (ESI MS) is known to be a versatile analytical technique for detection of very low concentrations of various diketopiperazines in different samples. Hence, we characterized our p-disubstituted phenyldiketopiperazines 1 ( R = H ), 2 ( R = NO2 ) and 3 ( R = -N(CH3) ) by ESI MS. We have shown that the majority of the fragment ions in the ESI mass spectra originated from reactions initiated by one of the nitrogen atoms of the piperazine ring.

Tridentate ligands, such as iminodiacetamide derivatives and transition metals can form hexacoordinated complexes of ML and ML2 stoichiometry1. Ligands imda-pea and imda-phe prepared in this work have chiral chains with amide groups (pea = (S)-1-phenylethanamine and phe = L-Phenylalanine methyl ester) that could form hydrogen bonds between two ligands in a complex of ML2 stoichiometry. For the ligand imda-pea, one hydrogen bond is possible, while two hydrogen bonds are possible for imda-phe, allowing the formation of different secondary structures. These compounds could have potential use in enantioselective catalysis. In complexes with hydrogen bonded secondary structures, chirality can be transmitted to the metal centre by ''backdoor induction'' from distant chiral groups, and the metal centre can selectively catalyze enantioselective reactions2. In this work, ligands imda-pea and imda-phe were prepared in two steps, by standard amide coupling reactions, followed by nucleophilic substitution with chloroacetamide precursors. The complexes were characterized in solid state by IR spectroscopy. In solution, the Zn(II) complexes were studied by 1H NMR spectroscopy and the Cu(II) complexes by UV-Vis spectroscopy. The transfer of chirality to the metal centre was studied by CD spectroscopy.

Bis(2-picolyl)amine (bpa) and its derivatives are tridentate ligands known for the formation of complexes with late transition metals that found use as enzyme mimics, metal ion sensors and anticancer agents. In the Cambridge Structural Database, a variety of bpa complexes are described, such as monomers, dimers and coordination polymers. In this work, six chiral bpa ligands and their complexes with Zn(II) and Cu(II) were prepared and characterized by NMR, UV-Vis and CD spectroscopy. The stoichiometry, stereochemistry and possibility of different hydrogen bonding patterns were studied by DFT calculations. To optimize the formation of ML2 complexes, several variations were introduced into the ligand structure, such as the length of the CH2 linker, orientation of the amide group (-CO-NH- or -NH-CO-) and different chiral substituents. In ML2 complexes, the ligands have the possibility of forming one or two intramolecular hydrogen bonds. In these hydrogen bonded secondary structures, transfer of chirality by ''backdoor induction'' to the metal centre is possible and such complexes could selectively catalyse enantioselective reactions.

Reaction of the bis(2-picolyl)amine (bpa) ligand with copper(II) results in formation of four complexes with a large structural variety: monomer, bromo-bridged dimer, a coordination polymer and a cyclic trimer that binds atmospheric CO2. Here we present an X-band electron spin resonance (ESR) study of the copper(II) complexes, from room down to liquid helium temperature. The spectral simulations were obtained using spin-Hamiltonian approach and EasySpin software [1]. The results obtained from the study will be discussed in terms of copper coordination geometries and magnetic interactions of copper spins S = 1/2 [2, 3].

Tridentate ligands, such as iminodiacetamide (imda) derivatives and transition metals are known to form complexes of ML and ML2 stoichiometry. In hexacoordinated ML2 complexes, depending on the orientation of the ligands, mer, trans-fac and Δ- or Λ-cis-fac geometrical isomers are possible. Our aim is to study substituent effects on the stereochemistry of imda complexes, as model complexes for catalysts in enantioselective reactions. In the solid state we observed mainly trans-fac isomers, while the cis-fac isomer was obtained only for R, R' = H. In acetonitrile solution, NMR spectroscopy reveled formation of trans-fac isomers at room temperature (R' = iPr) or at 0°C (R' = Bn). The substituent on the central amine nitrogen was also found to influence the N-M bond strength, which was studied with variable temperature NMR. The relative stabilities of the isomers depending on the ligand substituent were determined using DFT calculations.

Click chemistry, an approach to synthesis using fast, versatile and high yielding reactions, has recently attracted attention as a simple way of preparing a wide scope of products. 1, 2, 3‐ triazoles can be prepared by Huisgen 1, 3‐ cycloaddition of azides and alkynes, where copper (I) as the catalyst dictates the formation of a 1, 4‐disubstituted triazole ring [1]. The triazole group is a weak base and depending on the conditions it can act both as a donor or acceptor of protons, as well as a ligand for coordinating metals [2]. The large dipole moment of triazole molecules (5 D) allows easy formation of hydrogen bonds, as well as dipole‐dipole and π interactions, which increase their solubility and allow binding to biological targets [3]. In this work, bis‐ and mono‐1, 2, 3‐triazole ligands and their metal complexes were prepared. Complexes of the thiazole ligand 4c were fully characterized by NMR, UV/Vis and IR spectroscopy. (SMD)/M05‐2X/6‐31+G(d)/LanL2DZ + ECP calculations helped in interpreting relative stabilities of mer, trans‐fac and cis‐ fac isomers of ML2 complexes. The prepared ligands and complex 4cZn will be tested for their antiproliferative properties.

Bis(2-picolyl)amine (bpa) ligands are tridentate ligands, with flexible linking arms that allow both meridional (mer) and facial (fac) coordination geometry. The formation of geometrical isomers, as well as the formation of complexes of different stoichiometry and coordination number, can be influenced by a number of effects, for example the coordinating ability of the counterion. Counterions of strong coordinating ability, due to their localized charge, compete with the ligands for binding the metal, and often lead to formation of ML or bridged complexes. In literature, similar complexes were studied as models for multinuclear zinc enzymes for capturing CO2. Large counterions of dispersed charge, such as perchlorate do not interfere with binding of the ligand, enabling formation of ML2 complexes. A similar system was described as a fluorescent Zn(II) indicator. In this work, we studied how different counterions effect the stoichiometry, coordination number and geometry of complexes. Crystal structures of four Zn(II) and four Cu(II) complexes were determined, revealing complexes of a large structural variety: monomeric ML and ML2, bridged dimers, a coordination polymer and a cyclic trimer that binds atmospheric CO2. For Cu(II) complexes, the local magnetic properties were studied by ESR spectroscopy, while NMR spectroscopy was used to study the solution structure of Zn(II) complexes. For the ML2 complex obtained with the perchlorate anion, DFT calculations were used to determine the relative stability of isomers.

Heksakoordinirani kompleksi prijelaznih metala s tridentatnim liganadima kao što su imda (iminodiacetamid) i bpa (bis-(2-pikolil)amin), mogu imati različite koordinacijske poliedre: oktaedar i trigonsku prizmu. U slučaju oktaedra, mogući su različiti geometrijski izomeri (mer, trans-fac i cis-fac).1 U literaturi postoji opsežna karakterizacija imda, bpa i sličnih sustava u čvrstom stanju, no karakterizacije u otopini ima značajno manje. U ovom radu istraživana su dva ligandna sustava različitih stereokemijskih preferenci-imda i bpa. Dok se pregledom literature može uočiti da bpa2 tvori uglavnom cis-fac, imda3 tvori uglavnom trans-fac izomere. Cilj ovog istraživanja je ispitati utjecaje na stereokemiju kompleksa, kao što su skupine različitih elektronskih i steričkih svojstava na ligandu te protuoini različitih koordinacijskih svojstava. Kompleksi su također karakterizirani u otopini NMR i UV-Vis spektroskopijom. U čvrstom stanju kompleksi su karakterizirani difrakcijom X-zraka na monokristalnim i praškastim uzorcima, IR spektroskopijom i termogravimetrijom. Određeno je devet kristalnih struktura imda kompleksa ML2 stehiometrije te osam struktura bpa kompleksa različitih stehiometrija i koordinacijskih brojeva.

The amide group, an important structural motif of amino acids, and therefore, peptides and proteins, can act both as a donor (N-H) and acceptor (C=O) of hydrogen bonds. Studying the amide bond hydrogen bonding ability, gives insight into the formation of secondary and tertiary protein structures. Iminodiacetamide derivatives are well known ligands for late transition metals that give access to a great variety of stuctural motifs and can be conjugated to different molecules, such as the ferrocenyl group, which due to its stability in aqueous and organic media, found use in many biological applications. In this work, we present the crystal structures of two solvatomorphs of a ferrocene amide conjugate Fc-eda-imda and Fc-eda- imda × CDCl3. The difference between the solid state structures of both solvatomorphs is described in detail, using single crystal and powder X ray diffraction. Also, the difference between the structure in the solid state and in chloroform solution is studied with 1H NMR and IR spectroscopy.

Hexacoordinated transition metal complexes of tridentate ligands L with ML2 stoichiometry can form several geometrical isomers: meridional, trans-facial, and delta or lambda cis-facial. The configuration of isomers is affected by steric and electronic properties of the ligands and coordinating ability of the counterions [1]. Derivatives of iminodiacetamide (imda) are studied as tridentate ligands and in all known complexes the iminodiacetamides act as O, N, O’ chelators. The Cambridge Structural Database (CSD) contains crystallographic data for less than 20 metal complexes with iminodiacetamide or its N- substituted derivatives. All reported complexes of N-substituted imda derivatives are trans-facial isomers [2]. In this communication we present the synthesis and characterization of phenyl iminodiacetamide derivatives (L1-L6) and their ML2 complexes with transition metals, M = Zn(II), Co(II), Ni(II) or Cd(II). The amide nitrogen atoms were substituted with phenyl groups in order to increase their solubility in common organic solvents and enable characterization of complexes in solution. To test the effect of the ligands electronic properties on the complex configuration, ligands were prepared with electron donor or electron withdrawing groups on the para- position of phenyl rings (R). The complexes were characterized in solid state (single crystal X-ray diffraction, IR, TG) and in solution (1H and 13C NMR, IR, UV-Vis).

Transition metal complexes with coordination number 6 can exhibit octahedral or trigonal prismatic geometry. The distinction between the geometries can be made based on several angular parameters: θ, ρ and ω. Continuing our recent research on tridentate ligands (L) with two identical terminal coordination sites like bis(2-picolyl)amine (L = bpa), we now extend our attention to phenyl iminodiacetamides (L = imda). In this communication we present hexacoordinated ML2 complexes with different central metal cations, M = Zn2+, Co2+, Ni2+, Cd2+. Crystal structures of several ML2 complexes determined by X-ray diffraction on single crystals will be compared with structures calculated by M05-2X/LanL2DZ method. In addition, the calculated energies for the different isomers will be discussed (mer-, cis- or trans-). Starting from the unsubstituted ligand, various electron donating or withdrawing substituents will be added to bpa or imda systems in order to evaluate their influence on the geometry and energetics of the studied complexes. Our goal is to identify the factors governing the stabilization of cis-isomers which could be used as catalysts in asymmetric reactions.

The aim of this thesis was to prepare composite nanomaterials for targeted delivery of radionuclides used for cancer diagnosis and therapy. Hydroxyapatite and TiO2 nanoparticles were used as vehicles for targeted delivery because of their suitable properties such as biocompatibility and radiochemical stability. Nanocomposites were prepared by precipitating phosphonate ligands or polyethylene glycol with nanoparticles. The role of the phosphonates is binding of radionuclides and stabilisation of nanoparticles. Prepared nanocomposites were labelled with 99mTc, a gamma emmiter used in tumor imaging and 223Ra, an alpha emmiter used in targeted alpha therapy. Phosphonic acids ethylenediamine tetra(methylenephosphonic) acid, propylenediamine tetra(methylenephosphonic) acid and 1,2-cyclohexyldiamine tetra(methylenephosphonic) acid were purified by ion exchange chromatography and used for preparation of nanocomposites. Besides mentioned ligands, methylene diphosphonic acid, etidronic acid, zoledronic acid, pamidronic acid and polyethylene glycol were used for experiments. For labelling with 99mTc, the best yields were obtained for 99mTc-CDTMP-HAp (89%), and 99mTc-PDTMP-HAp (93%) stabilised before labelling and 99mTc-MDP-HAp (92%) and 99mTc-HEDP-HAp (89%) stabilised during their preparation. TiO2 nanocomposites all had yields >93%. Nanocomposites 223Ra-zoledronic acid-HAp stabilised after labelling showed the best yields (60%) for labelling with 223Ra. Cilj ovog rada bio je priprema kompozitnih nanomaterijala za ciljanu dostavu radionuklida koji se koriste u dijagnostici i terapiji raka. Nanočestice hidroksiapatita i TiO2 korištene su kao nosači za ciljanu dostavu zbog njihovih pogodnih svojstava, kao što su biokompatibilnost i radiokemijska stabilnost. Nanokompoziti su pripravljeni miješanjem fosfonatnih liganda ili polietilen glikola s nanočesticama. Uloga fosfonata je vezanje radionuklida i stabilizacija nanočestica. Pripremljeni nanokompoziti obilježeni su s 99mTc, radionuklidom koji emitira gama zračenje i koristi se u dijagnostici tumora te 223Ra, koji emitira alfa zračenje i koristi se u ciljanoj alfa terapiji. Fosfonske kiseline, etilendiamin tetra(metilenfosfonska) kiselina, propilendiamin tetra(metilenfosfonska) kiselina i 1,2-cikloheksildiamin tetra(metilenfosfonska) kiselina, pročišćene su ionsko izmjenjivačkom kromatografijom i korištene su za pripravu nanokompozita. Osim navedenih liganda, u eksperimentima su korištene i metilen difosfonska, etidronska, zoledronska i pamidronska kiselina te polietilen glikol. Za obilježavanje s 99mTc, najbolje iskorištenje dobiveno je za 99mTc-CDTMP-HAp (89%), i 99mTc-PDTMP-HAp (93%) stabilizirane prije označavanja i 99mTc-MDP-HAp (92%) i 99mTc-HEDP-HAp (89%) stabilizirane tijekom sinteze nanočestica. Svi nanokompoziti TiO2 imali su iskorištenje veće od 93%. Nanokompoziti 223Ra-zoledronska kiselina-HAp stabilizirani nakon obilježavanja pokazali najbolje iskorištenje (60%) za označavanje s 223Ra.

The design and development of novel heterocyclic molecules for (chemo)sensing applications is of great current interest in organic chemistry and sensing technology, where click-derived triazoles are one of the most advanced and attractive building blocks. In this work fast and simple click reaction for the synthesis of novel class of 1, 2, 3- triazol- coumarin conjugates for optical sensing applications is described. Photophysical and photochemical characterization of the newly synthesized compounds was performed using UV- Vis absorption and fluorescence spectroscopies.

Cilj ovog rada je prikaz brze i jednostavne click reakcije za sintezu potencijalnog optičkog senzora, spoja 7-(4-(4-aminofenil)-1H- 1, 2, 3-triazol-1-il)-4-metil-2H-kromen-2- ona (spoja 3) te njegova imobilizacija u tanki polimerni film, vrstu ionsko selektivnih optoda koje omogućuju jednostavno određivanje različitih analita, jeftine su i pogodne za jednokratnu upotrebu. Spoj 3 pripravljen je na dva načina. U prvom načinu azid 2 pripravljen je klasičnom reakcijom diazotacije, a u drugom načinom azid 2 pripravljen je pomoću diazonijevog tosilata. Konačni spoj 3 u oba slučaja pripravljen je bakar (I) kataliziranom 1, 3- dipolarnom cikloadicijom. Ispitana je ovisnost svojstava spoja 3 o vrijednosti pH otopina univerzalnog pufera i etanolnih otopina, o polarnosti otapala te o prisutnosti metalnih iona. Mjerenja su provedena metodama UV-vidljive apsorpcijske i fluorescencijske spektrofotometrije pri čemu je koncentracija spoja za sva mjerenja bila 1*10-5 M. Tanki polimerni filmovi pripravljeni su spin- coating tehnikom, odnosno brzim razmazivanjem smjese na poliestersku foliju te ravnomjernom raspodjelom smjese tehnikom brzog rotiranja podloge. Spoj 3 pokazuje pojačanje intenziteta fluorescencije te hipsokromni pomak u kiselom mediju što ukazuje na njegovu potencijalnu primjenu kao pH senzora. U nepolarnim otapalima dolazi do stvaranja nove emisijske vrpce, odnosno zelene fluorescencije. Prisutnost metalnih iona nije dovela do promjene spektrofotometrijskih svojstava spoja te spoj 3 nije pogodan za upotrebu kao senzor za metale. Svojstva spoja u imobiliziranom stanju razlikuju se od svojstava spoja u otopini te bi za njegovu primjenu trebalo provesti daljnja ispitivanja. Ovaj rad je izrađen na Fakultetu kemijskog inženjerstva i tehnologije, Sveučilišta u Zagrebu, pod mentorstvom prof. dr. sc. Ivane Steinberg, na Zavodu za opću i anorgansku kemiju.

Cilj ovog rada bio je ispitati potencijalnu primjenu novih derivata benzimidazola, 5-fenilbenzimidazo[1, 2-a]kinolin-6-karbonitrila (1) i 2-amino-5-fenilbenzimidazo[1, 2-a]kinolin-6-karbonitrila (2) kao optičkih pH senzora, počevši od istraživanja njihovih svojstava u otopini te imobiliziranom stanju u obliku tankih plastificiranih (poli(vinil-klorid)) filmova. UV-vidljivom apsorpcijskom i fluorescencijskom spektrofotometrijom ispitana su svojstva spojeva u vodenim i etanolnim otopinama u rasponu vrijednosti pH od 1 do 13. Smjesa za pripravu tankih polimernih filmova sadržavala je (izraženo u masenim udjelima): 33% poli(vinil-klorida) (PVC-a), 66% omekšivala dioktil sebacata (DOS) i ispitivani spoj 1 ili 2, otapalo THF (tetrahidrofuran) te lipofilni dodatak kalijev tetrakis(4-klorofenil) borat (PTCB). Filmovi su pripravljeni spin-coating tehnikom, odnosno tehnikom brzog rotiranja. Tanki filmovi su spektrofluorimetrijski karakterizirani na zraku te nakon uranjanja u vodene i etanolne otopine u rasponu vrijednosti pH od 1 do 13.

Small pore zeolites comprise 8-membered ring pore opening within their framework. They are commercially exploited in automotive catalysis, and they also excel in the industrial production of olefins from methanol (MTO) [1, 2]. In addition, they are extensively studied in gas adsorption, e.g. for selective uptake of CO2 from CH4 that is of great importance for upgrading of natural gas and biogas, as well as for nitrogen oxides abatement from exhaust gases [3, 4]. Herein is reported the preparation of LEV-type as well as LEV/ERI-type intergrown materials at temperatures ranging from 100-200 °C.

High alumina LTA-type zeolite material, so called zeolite A (Si/Al = 1), is an archetype drying agent (water adsorbent) as well as ion exchanger (e.g. in water softening) [1]. Incorporating more Si in the framework, i.e. increasing Si/Al ratio, renders this kind of materials more (hydro)thermally stable and apt for catalytic application, in particular for vehicle exhaust gases purification [2, 3]. Cu-LTA were found exceptionally active catalysts in NH3-SCR even after hydrothermal aging at 900 °C, the temperature at which the commercial catalyst deforms and loses activity [4]. In the scope of this research challenges of preparing high/all- silica LTA zeolites are going to be addressed. Besides, several examples of their successful preparation will be demonstrated.

Topological nodal line semimetals (NLSMs) that have been intensively studied lately are three- dimensional materials with linear Dirac electron energy bands crossing at dispersive nodal lines. We investigated the plasmon collective mode of a dispersive topological nodal line semimetal with two-dimensional Dirac electron energy bands and the long range three-dimensional Coulomb electron– electron interaction within the random phase approximation (RPA). We analyzed the effect of the interband electron–hole excitations on the plasmon mode by evaluating the energy-loss function. Our calculations showed that the plasmon mode was optical, strongly anisotropic and hardly damped as it entered into the interband electron–hole continuum. The obtained results for the plasmon mode are consistent with earlier experimental and theoretical results for these materials.

The biological activity, conformational stability, and therapeutic application of peptides depend on their secondary structure. Therefore, the main goal in the design and preparation of synthetic peptides is to nucleate the formation of secondary structure elements. It has been shown that various ferrocene templates, when incorporated into peptides, induce the formation of hydrogen bonds, which allows the formation of turn- and -sheet- like structures [1, 2]. Here, we provide an overview of hydrogen-bonding patterns in ferrocene peptides based on detailed spectroscopic, DFT and crystallographic analyses.

Pollen carries male plant genetic material encapsulated in a hard protective shell containing flexible, soft regions—apertures. The mechanical design of the shell regulates how the pollen grain folds into itself (infolds) upon dehydration, which often occurs once it becomes exposed to the environment. The same design also guides the response of pollen grains to hydration which may lead to bursting of the pore and the leakage of the pollen proteins in the atmosphere – this process releases submicronic pollen particles, which can provoke strong allergic reactions in sensitive individuals. Infolding pathways of pollen grains are investigated by studying elastic deformations of inhomogeneous thin shells. Different pathways are governed by the interplay between the elastic properties of the hard and soft regions of the pollen shell and by the aperture shape, number, and size. We delineate regions of mechanical parameters of the pollen grain which lead to complete closure of all apertures, thus reducing water loss and presenting evolutionary viable solutions to the infolding problem [1]. We also show that the apertures, although important for the initiation of the pollen tube, also present a weak regions of the grain wall and that they are prone to bursting once the pollen grain swells enough in humid atmosphere [2]. [1] A. Božič, A. Šiber, Proc. Natl. Acad. Sci. U.S.A. 117 (2020) 26600. [2] A. Božič, A. Šiber, Biophys J 121 (2022) 782.

Dasatinib (DAS) is a second-generation tyrosine kinase inhibitor used for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia and acute lymphoblastic leukemia. However, this drug is characterized by poor gastrointestinal absorption and low bioavailability due to its low aqueous solubility. A promising approach to improve the properties of DAS is to modify its crystalline structure by supramolecular structural modifications, such as the preparation of a co-amorphous system. This research is focused on the application of the green co-grinding method to prepare amorphous solid dispersions of DAS in a matrix of polyvinylpyrrolidone (PVP). Several favorable events were expected: a reduction in the particle size of the drug and thus an increase in the specific surface area, better wettability, and possible intermolecular interactions between DAS and PVP, which could also improve the dissolution rate of the drug and thus its bioavailability. Amorphous solid dispersions and fluidized bed melt granulation were used to prepare tablets with strictly defined aimed properties. In vitro dissolution tests confirmed that this particular drug could be mechanochemically activated in terms of improving its dissolution properties.

Flexible crystals ‒ a rapidly growing class of materials that combine a long- range order of a typical crystal structure with a certain degree of mechanical flexibility. So far, this mechanical flexibility has been reported for a significant number of organic molecular crystals, but mechanical properties of metal– organic crystalline solids have been less understood. Recently, it has been shown that coordination polymers can serve as ideal models of metal-organic systems that might result in exceptional flexible crystals. In this work, we have prepared needle-like crystals of coordination polymers of copper(II) halides with 3-nitropyridine and determined the type of their mechanical response, which was subsequently quantified. Moreover, we examined the crystals’ flexible responses to the applied thermal stimuli using hot-stage microscopy along with the electrical properties using impedance spectroscopy, the results of which will be discussed in detail.

Discovery of crystals that can move under the influence of heat, light or mechanical stimuli completely changed a perception of crystals as static systems, but also made them excellent candidates for a variety of applications in advanced technologies, e.g. thermal actuators, or self- healing materials. Recently, it has been shown that in addition to two commonly observed mechanic responses, elastic and plastic, crystals are able to present a whole spectrum of different adaptabilities to external pressure. To provide a deeper insight into those interesting crystalline behaviors, herein we opted for crystals of coordination polymers of CuBr2 and CdBr2 with 3, 5- lutidine (3, 5-lut), [CuBr2(3, 5-lut)2]n (1) and [CdBr2(3, 5-lut)2]n (2). It was shown that both crystals were 2D isotropically responsive, but while 1 was purely plastic, 2 was elastic→plastic. Computational DFT methods were used to complement experimental findings by simulating the deformation of the unit cells along the crystallographic axes. Comparison of the fitted potential energy curves enabled us to better understand the effect of intermolecular interactions on mechanically induced flexibility