Starch and gelatin are suitable natural polymers for the large-scale production of biodegradable products to replace non-degradable petroleum-derived products. However, their poor water resistance restricts their use in certain applications. The aim of this study is to investigate the effects of beeswax (BW) content on the color, crystallinity, morphology, water resistance, thermal behavior, chemical composition, and mechanical properties of a starch/gelatin bioplastic (TPSG). TPSG Sheets with BW contents of 0, 5, 10, and 15 wt% were fabricated from extruded pellets by compression molding. It was observed the optimal BW content of 10 wt% produced a bioplastic with a tensile strength of 4.68 MPa, a water solubility of 21.76 % and degree of swelling of 95.06 %, a water contact angle of 118.01° and color lightness value f 96.04. The continuous and homogeneous internal structure of TPSG/BW10 confirmed the good compatibility of the components. Fourier transform infrared spectroscopy revealed hydrogen bonding between starch, gelatin and BW, while X-ray diffraction analysis showed that crystallinity increased with increments of BW content. Moreover, the incorporation of beeswax delayed the onset of the biodegradation of TPSG. Therefore, TPSG/BW10 could be a viable candidate for sustainable packaging applications, particularly in food packaging where moisture barrier properties are crucial.

We studied the thermal behaviour of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (emimNTf2) in mixtures with γ-butyrolactone (GBL), solutions often used as solvents, electrolytes in lithium-ion batteries and supercapacitors, or electrolytes in electrochemical energy storage devices, stored under common storage/usage conditions for 2 years. We repeatedly measured the simultaneous thermogravimetric—differential scanning calorimetric (TG-DSC) curves of the systems in the mole fraction range of 0.05 < emimNTf2 < 0.9 to see how the changing external parameters like temperature and/or pressure alter the physical properties and behaviour of the mixtures. To interpret the observed changes in the thermal curves, density function theory (DFT) calculations and molecular dynamics (MD) simulations were carried out. We discussed how the formation of unstable intermediates in the mixtures, due to changes in the ambient conditions over the long period of storage, affects the stability of the systems over the full mole fraction scale and what might be the impact of such changes on the practical applicability of the mixtures.

The growing awareness of food safety and environmental sustainability has driven increased research into the development of safe, biodegradable food-packaging films. A novel chromogenic film based on a starch/polyvinyl alcohol (PVA) blend reinforced with hydroxyapatite (HAp) from fish scale was functionalized with Griess reagent to indicate the presence of nitrite in food. The aim of this study was to investigate the effects of HAp content (0, 0.25, 0.5, 0.75 and 1 wt%) on the properties of the proposed film. The starch/PVA film containing the optimal HAp content of 1 wt% produced a water contact angle of 123.62 degrees, a mass loss in water of 17.35%, and a degree of crystallinity of 28.03%. Moreover, the addition of HAp improved the thermal stability of the film and imparted a slight antioxidant property revealed in DPPH assays (5.67 +/- 3.31%). The starch/PVA/HAp composite film exhibited no cytotoxicity toward HDF and NOK-SI cells. Moreover, the starch/PVA film with 1 wt% of HAp reliably indicated the presence of NO2- in food samples. These results support the concept of producing highperformance food packaging from these environmentally friendly materials.

A new Schiff base of 2,6-diacetylpyridine and adamantane-1-carbohydrazide-L, as well as two of its solvatomorphic complexes with Co(II), viz. [Co(L)(H2O)(EtOH)][CoCl4] center dot EtOH center dot H2O (1) and [Co(L)(MeCN)(2)][CoCl4] center dot MeCN (2), were synthesized. The reaction of CoCl2 center dot 6H(2)O with the ligand in a molar ratio 2:1 in ethanol-acetone solvents gives complex 1, while the same reaction in acetonitrile-acetone solvents gives complex 2. Characterization involved elemental analysis, Fourier transform infrared spectroscopy (FTIR), conductometric measurements, thermogravimetric analysis, single-crystal X-ray diffraction (SC-XRD), and antioxidant tests. Structural analysis revealed ligand coordination in its neutral form as N3O2 pentadentate. The cobalt(II) is placed in a pentagonal bipyramidal environment in both complexes, where the donor atoms of the ligand (one pyridine nitrogen, two azomethine nitrogen, and two carbonyl oxygen atoms) form the base of this polyhedron, and solvent donor atoms occupy the axial positions. Detailed comparative analysis of the structural parameters of free ligands and the complexes, as well as their thermal characterization, is given, enabling a better understanding of the measured antioxidant activity. The results suggest the potential these compounds have in further examination of their biological activity, with the complexes being more active than the ligand itself.

The development of selective anticancer agents remains a central objective in medicinal chemistry. Here, we report the synthesis, structural characterization, and biological evaluation of the first metal complex of a quinoline-based thiazolyl-hydrazone ligand [(E)-2-(8-(quinolin-2-ylmethylene)hydrazinyl)-4-(4-tolyl)-1,3-thiazole)] (HL). Obtained octahedral Zn(II) complex [Zn(HL)2](NO3)2, (1), is based on two NNN tridentate coordinated ligands. In vitro cytotoxicity assays revealed that the complex exhibits potent and selective activity against lung adenocarcinoma A-549 and colorectal carcinoma HCT-116, while sparing non-tumorigenic human embryonic kidney HEK-293 cells. Mechanistic studies demonstrated that the complex induces S-phase arrest, inhibits DNA synthesis, and triggers significant DNA damage as indicated by increased p-γH2AX expression. These effects were accompanied by mitochondrial depolarization, caspase-3/7 activation, and phosphatidylserine externalization, confirming apoptosis via the intrinsic pathway. The compound further inhibited tumor growth in 3D spheroids and the chick chorioallantoic membrane model without overt toxicity. Compared to the free ligand and reference chemotherapeutics, the zinc complex showed improved efficacy and selectivity. These results highlight the potential of metal coordination to enhance the biological activity of hybrid ligands, supporting further development of this class of compounds as selective anticancer agents.

The impacts of structurally different dissolved organic carbon surrogates (DOC) on the adsorption of ibuprofen, caffeine and diclofenac (C0 2-3 mu g L-1) onto powdered activated carbon (PAC) were studied. The efficiency of PAC in a synthetic matrix (SM) was tested when low or high molecular weight DOC surrogates were added. Additionally, the impact of a potential natural coagulant was investigated. Different DOC surrogates differently affected the adsorption of tested organic micropollutants (OMPs). In the first 30 min, a positive impact of all types of surrogates on the adsorption of neutral and hydrophilic caffeine was observed, while for negatively charged ibuprofen and diclofenac, the impacts varied. The low molecular weight DOC (containing amino acids and resorcinol) positively impacted the adsorption of ibuprofen, while effects were not clear for diclofenac. The high molecular weight DOC decreased the degree of adsorption for both compounds. The mass transfer calculations showed that low molecular weight DOC accelerated the transport of OMPs. High molecular weight DOC slowed reaching equilibrium (within 48 h). Thermogravimetry confirmed that the DOC coating qualitatively changes during the adsorption, which also affects the OMPs removal. The addition of a natural coagulant affected ibuprofen and diclofenac adsorption. For neutral caffeine the effects were not clear.

Condensation of aminoguanidine hydrochloride and 2-(diphenylphosphino)benzaldehyde yielded a new Schiff base derivative with the formula (HL)Cl & sdot;H2O. In addition to the usual methods for identification and characterization, such as spectroscopic and thermal analyses, as well as crystal structure determination, its coordination properties were thoroughly investigated. The reaction of methanolic solutions of copper(II) salts (chloride, bromide, and nitrate) with the ligand resulted in the formation of diverse products. In the reaction of copper(II) chloride and the ligand, two complexes were formed, viz. (HLO)2[CuIICl4] (1) and [CuI(HL)Cl2] (2). During the formation of 1, the diphenylphosphino residue of the ligand underwent oxidation. The reaction between the bromide salt and the ligand led to the formation of a mixture of two complexes with [CuI(HL)(Br/Cl)Br] (3) as the dominant product and only a few crystals of [{CuI(HL)(mu -Br/Cl)(Br/Cl)}2] (4). An interesting feature of these compounds is the substitutional disorder of two halide anions in different coordination sites. A similar phenomenon occurs in [CuI2(HL)2(mu -Cl)(mu -NO3)ClX], where X = Cl, NO3 (5), which is formed under the same reaction conditions when the nitrate salt is used. All the complexes were characterized by elemental analysis, FTIR, UVVis, SC-XRD, PXRD, and TG-MS, except for complex 4 due to its low yield. Additionally, the antioxidant capacity of 1, 2, 3 and 5 was investigated in vitro, with the copper(I) complexes exhibiting greater activity.

In this paper, the coordination of 4-methylpyrazole (L) to Ni(II) and Zn(II) ions is studied through the reactions of Ni(OAc)2 center dot 4H2O and Zn(OAc)2 center dot 2H2O with 4-methylpyrazole in a 1:2 metal-to-ligand molar ratio in ethanol at room temperature. From the reaction mixtures, new complex compounds of formulae: [Ni(OAc)2L4] and [Zn (OAc)2L2] were crystallized. The crystal and molecular structure of the synthesized complexes were determined by single-crystal X-ray structure analysis. The coordination environment of Ni(II) in its complex is octahedral, while that of Zn(II) is tetrahedral. The compounds are characterized by IR spectra and elemental analysis. Their thermal stability, a crucial property, is analyzed by thermogravimetry. To get a better insight into the decomposition mechanism coupled TG-MS measurements were carried out, too. The tests of the antioxidative activity of the new complexes on DPPH radical showed that the Zn(II) complex is more effective than the Ni(II) complex.

[Carbonatotetraamminecobalt(III)] permanganate monohydrate was synthesized first in the metathesis reaction of [Co(NH3)4CO3]NO3 and NaMnO4 in aqueous solution. Its thermal dehydration at 100 °C resulted in phase-pure [Co(NH3)4CO3]MnO4 (compound 1). Compounds 1 and 2 (i.e., the hydrated form) were studied with IR, far-IR, and low-temperature Raman spectroscopies, and their vibrational modes were assigned. The lattice parameters were determined by powder X-ray diffraction (PXRD) and single crystal X-ray diffraction (SXRD) methods for the triclinic and orthorhombic compounds 1 and 2, respectively. The detailed structure of compound 2 was determined, and the role of hydrogen bonds in the structural motifs was clarified. UV studies on compounds 1 and 2 showed the distortion of the octahedral geometry of the complex cation during dehydration because of the partial loss of the hydrogen bonds between the crystal water and the ligands of the complex cation. The thermal decomposition consists of a solid phase quasi-intramolecular redox reaction between the ammonia ligands and permanganate anions with the formation of ammonia oxidation products (H2O, NO, N2O, and CO2). The solid phase reaction product is amorphous cobalt manganese oxide containing ammonium, carbonate (and nitrate) anions. The temperature-controlled thermal decomposition of compound 2 in toluene at 110 °C showed that one of the decomposition intermediates is ammonium nitrate. The decomposition intermediates are transformed into Co1.5Mn1.5O4 spinel with MnCo2O4 structure upon further heating. Solid compound 2 gave the spinel at 500 °C both in an inert and air atmosphere, whereas the sample pre-treated in toluene at 110 °C without and with the removal of ammonium nitrate by aqueous washing, gave the spinel already at 300 and 400 °C, respectively. The molten NH4NO3 is a medium to start spinel crystallization, but its decomposition stops further crystal growth of the spinel phase. By this procedure, the particle size of the spinel product as low as ~4.0 nm could be achieved for the treatments at 300 and 400 °C, and it increased only to 5.7 nm at 500 °C. The nano-sized mixed cobalt manganese oxides are potential candidates as Fischer-Tropsch catalysts.

The tetrazole moiety remains one of the most interesting scaffolds in the development of new high-energy density materials (HEDMs) because of its desired characteristics, such as high nitrogen content and heat of formation (HOF). The combination of several heterocycles with high HOF seems to be a promising strategy for obtaining energetic materials with superior properties. Herein, we report the synthesis and characterization of a tetrazole polymer, polymethylenetetrazole (PMT), as a potential HEDM. The compound was characterized using NMR, IR, and Raman spectroscopy. Its weight average molecular mass was obtained by static light scattering (SLS), and its physical properties by powder XRD analysis. The density, sensitivity to friction (FS), and impact (IS) of the compound were determined as well. The results of the thermal and energetic properties of PMT suggest that this polymer could be an insensitive explosive.

The synthesis of the first Ag(I) complexes with ethyl-5-amino-1-methyl-1H-pyrazole-4-carboxylate (L) is presented. The reaction of AgClO4 with the ligand in a molar ratio of 1:1 gives a bis(ligand) complex [AgL2]ClO4 (1) in the presence of 4-formylbenzonitrile, monoperiodic polymer {[AgL2]ClO4}n (2). Characterization involved IR spectroscopy, conductometric measurements, thermogravimetric analysis, antioxidant tests, powder, and single crystal X-ray diffraction. Structural analysis revealed ligand coordination in a monodentate manner through the nitrogen atom of the pyrazole ring in both complexes. Complex 1 displayed a linear coordination environment for Ag(I), whereas, in complex 2, square-planar coordination was achieved with the additional involvement of two oxygen atoms from bridging perchlorate anions. Notably, the thermal properties of both isomers are found to be nearly identical. The significant antioxidant activity of the isomer with a reverse-oriented pyrazole-type ligand suggests its potential relevance in biological studies.

The solid state structures of zinc complexes with HLS1 and HLS3 ligands are reported, where HLS1 is 2-(2-(pyridin-2-ylmethylene)hydrazinyl)-4-fenil-1,3-thiazole and HLS3 is 2-(2-(pyridin-2-ylmethylene)hydrazinyl)-4-(4-methylphenyl)-1,3-thiazole. Structurally similar ligands form complexes of different structures with general formulas [Zn5(LS1)4(AcO)6] (1-AcO) and [Zn(LS3)(AcO)(H2O)] (3-AcO). The pentacoordinated complex 3-AcO exhibits NNN tridentate ligand coordination mode, with additional oxygen donor atoms from a water molecule and acetate anion. The structure of 1-AcO is unique as it is the first example of a pentanuclear complex with pyridyl-based thiazolyl-hydrazone ligands, containing an unprecedented centrosymmetric Zn3(AcO)6 cluster. Photophysical studies showed that 1-AcO is not photoactive, while 3-AcO displayed photoluminescent emission, attributed to ligand-based transitions as determined by time-dependent density functional theory (TD-DFT) calculations. This study underscores the role of molecular symmetry in predicting the photoactivity of at least Zn(II) complexes containing photo-inactive ligands.

A unique compound (compound 1) with structural features including an unprecedented tridentate-bridging coordination mode of permanganate ions and an eight-coordinated (rhombohedral) κ1-chlorido and tridentate permanganato ligand in a potassium complex containing coordination polymer (CoIII(NH3)6]n[(K(κ1-Cl)2(μ2,2′,2″-(κ3-O,O′,O″-MnO4)2)n∞) with isolated regular octahedral hexamminecobalt(III) cation was synthesized with a yield of >90%. The structure was found to be stabilized by mono and bifurcated N-H∙∙∙Cl and N-H∙∙∙O (bridging and non-bridging) hydrogen bonds. Detailed spectroscopic (IR, far-IR, and Raman) studies and correlation analysis were performed to assign all vibrational modes. The existence of a resonance Raman effect of compound 1 was also observed. The thermal decomposition products at 500 °C were found to be tetragonal nano-CoMn2O4 spinel with 19–25 nm crystallite size and KCl. The decomposition intermediates formed in toluene at 110 °C showed the presence of a potassium- and chloride-containing intermediates combined into KCl during aqueous leaching, together with the formation of cobalt(II) nitrate hexahydrate. This means that the CoIII–CoII redox reaction and the complete decomposition of the permanganate ions occurred in the first decomposition step, with a partial oxidation of ammonia into nitrate ions.

Knowledge of the coordination chemistry of 2,6-diacetylpyridine-bis(phenylhydrazone) (L) is limited, and this compound seems promising in many fields. We explored the reaction of methanolic solutions of chromium(III) nitrate and L in a 1:1 molar ratio and obtained the thin red crystals of the complex. It was characterized by FTIR, elemental analysis, and molar conductivity. Comparing the ligand and the complex spectra confirmed that coordination has occurred through azomethine and pyridine nitrogen atoms. Molar conductivity of DMF solution indicates that the complex is an electrolyte of the type 1:1. The chromium(III) is most likely situated in an octahedral environment of six nitrogen atoms of the two ligand anions, viz. [Cr(L–H)2]NO3. These findings enable the further investigation of the complex properties. Besides, future research will explore the impact of changing synthetic conditions on the reaction product and their characterization.

Zeolites, known for their unique structural and catalytic properties, are added to the natural rubber matrix to investigate their influence on the vulcanization process and the resultant properties of composites. The natural rubber-based composites were masticated with 4A synthetic zeolite (0, 5, 10, 15, 20, and 30 phr). The curing of the rubber compounds was monitored on a moving die rheometer at 150 °C. The isothermal DSC method was also used to study the curing process at 150 °C, 160 °C, and 170 °C. Based on the obtained results, it is assumed that there is an interaction between the components of the curing system and the surface of the zeolite particle, and that is why the vulcanization reaction starts earlier with an increase in zeolite in the rubber mixture. This underscores the significant role of zeolite in accelerating the curing reaction of natural rubber-based compounds. The composites were vulcanized in a press at 150 °C for 15 min. The chemical structure was analyzed using FTIR, and the sample morphology was examined using SEM. The degree of swelling in toluene and distilled water was determined. The tensile strength values, modulus of elasticity at 100% and 300% elongation, and elongation at break were measured using a universal testing machine. Hardness was assessed according to the Shore A scale. With a small addition of zeolite (up to 10 phr), there is no significant change in the tensile strength values. However, adding a considerable amount of zeolite to a natural rubber matrix results in a deterioration of the tested mechanical properties. It can be assumed that with large proportions of zeolite 4A MS in the composites, the mechanical properties deteriorated due to increased porosity. The amount of added zeolite affects the initial stages of thermal decomposition of the examined samples and the rest after the analysis at a temperature of 500 °C.

The applications of polyurethanes (PURs) have increased in recent years, because of their properties which can be adjusted according to their chemical structure. In this paper the preparation and detailed characterization of designed polyurethanes are reported for potential pharmaceutical applications. Two series of polyurethane networks were synthesized by using β- cyclodextrin ( β CD) or hydroxypropyl- β -cyclodextrin (HP β CD) as cross-linker for alicyclic isophorone diisocyanate (IPDI) and polyethylene glycols (PEG2000 or PEG6000) or poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (BLOCK 1100). The PURs were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). To visualize the morphology of the PUR samples, scanning electron microscopy (SEM) was used. FTIR assignments confirmed the formation of urethane linkages. XRD patterns revealed that the crystallinity decreased mainly due to the crosslinking process. The thermal stabilities of two series of polyurethanes have been correlated with their soft-segment molecular weights and structure of cross-linker. The increase of melting point is attributed to an increase in the size of the crystallites or an increase of complete crystalline phase due to the greater phase separation the hard and soft segments. The results from the SEM micrographs showed that βCD contribute s to the microphase separation. The results showed that by varying the cyclodextrins as a cross-linker and the chain length of the soft segments, the stated properties of polyurethanes as potential drug delivery carriers can be changed.

In this study, the synthesis of a Schiff base containing metal–organic frameworks (MOFs) of the UiO-67 family has been investigated. MOFs featuring free amine groups were successfully synthesized under mild solvothermal conditions using 2-amino-[1,1′-biphenyl]-4,4′-dicarboxylic acid and 2,2′-diamino-[1,1′-biphenyl]-4,4′-dicarboxylic acid as bridging ligands, resulting in MOFs with amine groups covalently linked to the bridging ligands. Both types of functionalized MOFs were post-synthetically modified with 4-formylbenzonitrile that resulted in imine formation. All the obtained compounds were characterized by PXRD, TGA, DTA, BET, NMR, and FTIR spectroscopy, while stability in water was monitored with SEM, EDS, and UV–VIS spectroscopy.

Aminoguanidine derivatives are the focus of research because of their various biological activities, such as antiviral, antibacterial, analgesic, antioxidant and anticancer. Their complexes with different metals are also examined and many of them show significant biological activity, too. Besides, some of the complexes show good photoluminescent properties and are used for the preparation of photoelectronic devices. Therefore, the synthesis, physicochemical, structural and thermal characterization of the complexes of 2-acetylpyridine-aminoguanidine (L) with copper (II) are described here. Under different reaction conditions, Cu(II) with L gives three complexes of different compositions. By varying the strength of basicity of the deprotonating agent used, it was proven here that the Schiff base given here could be coordinated in neutral or monoanionic form. In the presence of pyridine, a coordination polymer is obtained, while in the presence of ammonia/lithium acetate two different monomeric complexes were crystallised. Their physicochemical and thermal properties, as well as molecular and crystal structure, are determined.

Structural and spectroscopic characterization (SXRD, IR, liq. N2 temperature Raman, UV) of hexaamminecobalt(III) dibromide permanganate, [Co(NH3)6]Br2(MnO4) (compound 1) are described. There is a 3D hydrogen bond network including N-H???O-Mn and N-H???Br interactions, which could serve as potential reaction centers for solid-phase redox reactions between the ammonia ligands and/or bromide ions as reductants and permanganate ions as oxidant agents. The effect of the nature of halogen ions on the structural and spectroscopic properties of [Co(NH3)6]Br2(MnO4) and the analogous chloride compound, [Co(NH3)6]Cl2(MnO4) (compound 2) are discussed in detail.

Interest in Cd complexes has been growing in recent years. Cd complexes are considered a potential solution in the search for novel antibiotics that can fight antimicrobial resistance. In addition, Cd complexes draw attention to material chemistry. The main objective of this work was to prepare the first Cd(II) complexes with anionic forms of pyridine‐based thiazolyl hydrazone (THs) ligands HLS 2 [( E )‐4‐(4‐methoxyphenyl)‐2‐(2‐[pyridine‐2‐ylmethylene]hydrazinyl)thiazole] and HLS 3 [( E )‐2‐(2‐[pyridine‐2‐ylmethylene]hydrazinyl)‐4‐(p‐tolyl)thiazole] and perform their structural and spectroscopic characterization, as well as stability in solution and upon heating. Studies related to their biological activities and possible electrochromic applications are also being conducted. Complexes [Cd(HLS 2 ) 2 ] ( 1 ) and [Cd(HLS 3 ) 2 ] ( 2 ) have been characterized by a single‐crystal X‐ray diffraction and computational analysis of intermolecular interactions responsible for their solid‐state structures was performed. Thermal stability of 1 and 2 in the solid‐state was analyzed by TGA/MS, where as their solution stability was determined by the spectrophotometric titration method. Electrochemical and in situ UV–Vis spectroelectrochemical analyses of 1 and 2 were carried out to determine redox mechanisms and the influence of the substituents and electrolytes on their redox responses. The antioxidant capacity of both complexes was tested in antioxidant assays, while their antimicrobial activity was tested against five Gram‐positive and four Gram‐negative bacteria, as well as against three fungi. The obtained results indicate their potent antioxidant capacity. The antimicrobial activity of investigated compounds on almost all tested bacterial strains was stronger than that of the standard antibiotic erythromycin. The results of docking studies indicate that the minor groove DNA is the possible biological target of 1 and 2 .