Ni(II) complexes with (±)-trans-N,N′-bis(salicylidene)-1,2-cyclohexanediamine ([Ni(salcn)]), and its methyl ([Ni(salcn(Me))]) and tert-butyl ([Ni(salcn(Bu))]) derivatives have been synthesized. Anodic electropolymerization has been used to form electrodes modified by polymer films. FTIR and FTIR ATR methods showed that the obtained films consist of polymers of phenyl–phenyl type. The structure of poly[Ni(salcn)] is built with 1,2,4- and 1,2,3,5-substituted chains. A three-step process of the oxidation of the complexes and their films has been ascertained on the basis of cyclic voltammetry measurements. Furthermore we have also detected the oxidized species which probably serve as intermediates for polymer formation. The influence of the substituent in the phenolate moiety on the type of reaction after which the dimerization and polymerization reaction occurs has been evidenced. Furthermore the substituent dependence on the stability of the phenoxyl radical complex and the Ni(II)-phenoxonium cation has been noticed. For the [Ni(salcn(Bu))] complex, an additional electropolymerization step – the adsorption of the reagent on the electrode surface – has been observed.

Several peptidomimetic macrocycles containing a pyridine spacer and ring sizes ranging from 15 to 17 have been efficiently synthesized starting from valine and phenylalanine. The complexes formed have been investigated by potentiometry and NMR. Log K values show that phenylalanine derivatives 8 are consistently more stable than valine derivatives 7, whilst macrocycles with ring sizes of 16 members are the most appropriate for the complexation. The NMR data, in combination with molecular modeling, allow rationalization of the structure of the complexes formed and the participation of the aromatic rings from the side chain of phenylalanine in π-Ag⁺ interactions to be discarded.

Pisum sativum plants were treated for 3 days with an aqueous solution of 100 μM Pb(NO₃)₂ or with a mixture of lead nitrate and ethylenediaminetetraacetic acid (EDTA) or [S,S]-ethylenediaminedisuccinic acid (EDDS) at equimolar concentrations. Lead decline from the incubation media and its accumulation and localization at the morphological and ultrastructural levels as well as plant growth parameters (root growth, root and shoot dry weight) were estimated after 1 and 3 days of treatment. The tested chelators, especially EDTA, significantly diminished Pb uptake by plants as compared to the lead nitrate-treated material. Simultaneously, EDTA significantly enhanced Pb translocation from roots to shoots. In the presence of both chelates, plant growth parameters remained considerably higher than in the case of uncomplexed Pb. Considerable differences between the tested chelators were visible in Pb localization both at the morphological and ultrastructural level. In Pb+EDTA-treated roots, lead was mainly located in the apical parts, while in Pb+EDDS-exposed material Pb was evenly distributed along the whole root length. Transmission electron microscopy and EDS analysis revealed that in meristematic cells of the roots incubated in Pb+EDTA, large electron-dense lead deposits were located in vacuoles and small granules were rarely noticed in cell walls or cytoplasm, while after Pb+EDDS treatment metal deposits were restricted to the border between plasmalemma and cell wall. Such results imply different ways of transport of those complexed Pb forms.

Manganese(II) complexes with phenanthroline derivatives modified with different substituents were synthesized and incorporated into Nafion layers covering the surfaces of glassy carbon electrodes and were studied electrochemically. Formal potentials and apparent diffusion coefficients were calculated and discussed. The suitability for electrocatalytic oxidation of ascorbic acid and glycolic acid was examined. The surfaces of modified electrodes were characterized using atomic force microscopy.

We report the preparation of four new double-bridged PNP-lariat ether derivatives L1–L4 synthesized from precursor 1 by the subsequent substitution of chlorine atoms. The process consists of two steps. In the first one two reactive chlorine atoms of the –PCl₂ exocyclic moiety are substituted with respective nucleophiles: 2,2′-thiodiethanethiol 2 and 2,2′-oxydiethanethiol 3. In the second step the other chlorine atoms are substituted by aziridynyl 6 and pyrrolidinyl 7 groups, respectively. Their structures were established by MS, ¹H NMR, ³¹P NMR, ¹³C NMR spectroscopy. Furthermore, this work includes the investigation of complexation of silver(I) ions with the new ligands L1–L4 in methanol solution. The formation of the novel tetra-nuclear silver(I) complexes were observed. Stability constants were determined using a simple potentiometric titration. ¹H NMR, ³¹P NMR, ¹³C NMR spectra were recorded to investigate how the complexation of silver(I) ions by the investigated macrocyclic ligands occurs.