In this article, the reactivity of the Pt(II) anticancer compound picoplatin (cis-ammine-dichlorido-(2-methylpyridine)platinum(II) complex) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) was investigated by electrospray ionisation mass spectrometry (MS) and X-ray crystallography. MS data show binding of Pt to both proteins, with fragments retaining the 2-methylpyridine ligand. Crystallography identifies different binding sites on the two proteins, highlighting a different behaviour of picoplatin in the absence or presence of dimethyl sulfoxide (DMSO). The data suggest that the presence of DMSO favours the loss of 2-methylpyridine and alters the ability of the Pt compound to bind to the proteins. This study provides important insights into the pharmacological profile of picoplatin and supports the conclusion that coordinating solvents should not be used to evaluate the biological activities of Pt-based drugs.

This work is focused on the preparation and characterization of a series of cobalt complexes with Schiff base ligands that tend to adopt the shape of a trigonal prism. These complexes were synthesized, structurally characterized, and subsequently subjected to magnetic measurements using magnetometry and EPR spectroscopy. It was found that the complexes exhibit single-molecule magnet properties in the presence of a magnetic field. One of the complexes was magnetically diluted, revealing single-molecule magnet properties even in a zero field. These properties were further investigated through theoretical calculations.

In this work, we were dealing with the preparation of cobalt(II) complexes with 17-membered pyridine-piperazine macrocyclic ligand with atypical shape of trigonal prism coordination polyhedron. The ligand is coordinated by all five N-donor atoms and the last position is occupied by monovalent coligand – halide or pseudohalide. A negative value of the D-parameter describing the magnetic anisotropy in the range -20 to -41 cm^-1 was found for all complexes and the magnetic behaviour was investigated using theoretical calculations and magnetochemical measurements. Five field-induced single-molecule magnets were prepared and the magnetostructural correlations were investigated.

In this review article, we focused on a comprehensive overview of the structural types of multi-targeted Pt(IV) complexes, and they were categorized according to various criteria - a parent Pt(II) complex, a number and type of bioactive ligands, a type of second (innocent) axial ligand, and nuclearity. For the first time, we also reviewed multi-targeted Pt(II) complexes releasing cytotoxic Pt(II) species and bioactive ligand(s) as well, which also allowed a critical comparison of the two structural types. Special attention is paid to the discussion of the solution behaviour, activation and biological activity of the reviewed types of Pt complexes. Relevant comparison of these crucial features should be beneficial for future development of these pharmacologically highly perspective compounds.

The work is based on theoretical calculations focused on the magnetic properties of a series of dysprosocenium-type complexes. For these complexes, structure optimizations were performed, an analysis of their vibrational frequencies was conducted, and subsequently, their energy barriers U_eff were studied using methods based on CASSCF calculations. Furthermore, spin-phonon coupling was investigated, where a new method based on comparing the influence of molecular vibrations on the energy barrier was developed and compared to the already used method, which relies on crystal field parameters. The study of these substances revealed interesting structural correlations that could potentially be utilized in the design of single-molecule magnets with high blocking temperatures.

Half-sandwich Ru(II) and Ir(III) complexes with a thiadiazole-based ligand L1 (2-(furan-2-yl)-5-(pyridin-2-yl)-1,3, 4-thiadiazole) were synthesized and characterized by different analytical methods. The structures of the molecules were analysed and interpreted by computational methods (DFT and QT-AIM). The complexes showed the ability to oxidize NADH to NAD⁺, with the Ir(III) complexes exhibiting higher catalytic activity compared to their Ru(II) analogues. The results of in vitro testing of antiproliferative activity showed that Ir(III) complexes had no effect on healthy human fibroblasts, demonstrating their selectivity. In contrast, the complexes showed inhibitory effects on the metabolic and proliferative activity of cancer cells.

A series of Pd(II) complexes with tridentate chromone-based thiosemicarbazones (TSCs) was prepared, characterized by appropriate analytical techniques and studied for their anticancer activity. The TSC ligands used in the syntheses were subjected to in situ Michael addition. Two complexes exhibited low-micromolar antiproliferative activity against HeLa cervical cancer cells. The complexes were also studied for their mechanism of action and tested for their toxicity in vivo. In contrast to tissue-damaging cisplatin, normal cell and tissue architecture was observed in mice treated with Pd(II) complexes.

In this paper, a series of complexes [NiLn(L)₂(NO₃)₃] (Ln = Gd, Tb, Dy, Ho, Er, Yb, Y) with a Schiff base ligand were prepared. These complexes underwent characterization through X-ray structural studies and other physical-chemical methods. Additionally, their magnetic properties were explored using both experimental and theoretical methods. The results indicated that the complexes of Dy, Er, and Yb exhibit characteristics of field-induced single-molecule magnets.

In this work, a new hexadentate macrocyclic ligand containing one acetate pendant arm was synthesized. Its manganese complex was characterized in the context of its use as a potential MRI contrast agent. Using X-ray analysis, coordination number seven was confirmed, and in aqueous solution the seventh coordination site was occupied by a water molecule. Furthermore, advanced solution measurements (potentiometry, ¹⁷O NMR and ¹H NMRD, relaxometry) were performed, which showed very good thermodynamic stability of the manganate complex, its relatively small kinetic inertness and MRI efficiency of the complex (expressed by so-called relaxivity, r₁ = 2.45 mM⁻¹ s⁻¹ at 20 MHz, 25 °C), which corresponded to the presence of one coordinated water molecule. Compared to the manganate complex of the parent macrocycle without the acetate arm, this system represents a substantial improvement in thermodynamic and kinetic stability but a decrease in its efficiency/relaxivity.

The collaboration of the Department of Inorganic Chemistry (Faculty of Science, UP) and the Department of Clinical and Molecular Pathology (Faculty of Medicine and Dentistry, UP) has led to the development of a series of diiodoplatinum(II) complexes with simple imidazole derivatives, which have been shown to be highly effective against multiple myeloma cell lines, known to be a very difficult to treat type of cancer. The compounds studied and their use for the treatment of multiple myeloma are the subject of patent protection by the Industrial Property Office of the Czech Republic (patent CZ 309542 B6).

Diiodidoplatinum(II) complexes cis-[PtI₂(Lⁿ)₂] (1–7) with imidazole derivatives (Lⁿ) were considerably effective against multiple myeloma cell lines U266B1 and KMS12-PE. The leading compound 6 extraordinarily reduced viability of myeloma cells and exceeded the conventional anticancer drug cisplatin. Complex 6 also displayed markedly lower activity in the HS-5 stromal fibroblast cells than in myeloma cells, pointing out its pharmocologically prospective selectivity towards the cancer cells. No caspase 3/7 activity was detected in apoptotic myeloma cells treated by 6 indicating a different mechanism of apoptosis action from cisplatin. This work demonstrates that simple non-classical platinum(II) complexes represent a new perspective for a monotherapy of hard-to-treat multiple myeloma.

In this work, we thoroughly investigated the relationship between the crystallization rate and the critical temperature of spin crossover for an iron(III) complex exhibiting spin crossover and thermal hysteresis. By utilizing X-ray diffraction, we discovered that the critical temperature of spin crossover (T_1/2) is correlated with the crystallization time. Longer crystallization times resulted in crystals with lower T1/2 values, while shorter crystallization times resulted in crystals with higher T_1/2 values. The difference between the highest and lowest T_1/2 values observed can be as much as 50K.

Series of nickel and copper complexes with dicarboxylic acids (2,2 '-thiodiacetic acid, 3,3 '-thiodipropionic acid, 3,3 '-dithiodipropionic acid, and fumaric acid) and N-donor ligands (1,2-diaminopropane, 1,3-diaminopropane, 1,10-phenanthroline and N,N,N ',N '',N ''-pentamethyldiethylenetriamine) were synthesized and characterized using elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. These coordination compounds were tested for their antibacterial activities in vitro. The complexes demonstrated moderated antibacterial ac-tivity against Gram-positive and Gram-negative bacteria and could potentially be applied to treat skin wounds..

In this paper, a series of Ni(II) complexes with pyridine-based macrocyclic ligand L  with general formula [Ni(L)(X)₂]^0/2+ (X = Br⁻ (1), I⁻ (2), CH₃CN (3), NCS⁻ (4), imidazole (5)) was prepared and thoroughly investigated. X-ray molecular structures confirmed pentagonal bipyramidal geometry for all studied complexes with a strong Jahn–Teller distortion in the pentagonal equatorial plane. Direct current magnetic measurements revealed a strong easy-axis type of magnetic anisotropy which remains not affected in the halogenido series Cl⁻ → Br⁻ → I⁻, but which increases in the series with N-axial ligands in order CH₃CN → NCS⁻ → imidazole. This trend was explained with help of extensive theoretical calculations which confirmed a significant positive effect on magnetic anisotropy of changing axial ligand field as well as a negative effect of equatorial ligand field distortion and pointed to complexity of magnetic anisotropy tuning in pengatonal bipyramidal complexes with not strictly rigid macrocyclic ligand.

The publication deals with the preparation, structural and magnetic studies of four pentacoordinate Co(II) single molecule magnets. Entitled coordination compounds contain Cl- or Br- terminal ligands along with tridentate bis(benzimidazole)pyridine aromatic lignads decorated with n-alkyl chains. The comprehensive analysis of magnetic properties was focused on the diferences in the slow relaxation of magnetisation of investigated single molecule magnets. The investigated chlorido complexes exhibit the longer relaxation mediated via different relaxation mechanisms comparing to the isostructural bromido complexes. Those important finding will be very useful in the case of further molecular design of the novel single molecule magnets.

Cytotoxic half-sandwich complex [Ir(η⁵-Cp*)Cl(L²)]PF₆ (3) with 2‑pyridin-benzimidazole-based azo ligand was studied in the presence of various extra- and intracellular biologically relevant molecules. For the first time, the mixtures of 3 with ascorbic acid (ASA) and its combinations with reduced glutathione (GSH) and/or reduced nicotinamide adenine dinucleotide (NADH) were studied. 3 undergoes the azo bond reduction when mixed with NADH or ASA, but only ASA is recovered in the presence of GSH.

In the presence of carboxypeptidase, the hydrolytically stable complex [Os(η⁶-pcym)(L2)Cl]PF₆ (2) partially released the bioactive substituent indomethacin, bound through the amide bond to the chelating 2-(1,3,4-thiadiazol-2-yl)pyridine-based moiety of L2. Stability in the presence of other relevant biomolecules (GSH, NADH, GMP) and cancer cell viability were also studied.

A series of four mononuclear manganese(III) complexes coordinated with photo-active hexadentate azobenzene ligand, [Mn(5azo-sal2-323)](X) (X^– = Cl, BF₄, ClO₄, PF₆), were prepared. The impact of various counter anions on the stabilization and switching of the spin state of the manganese(III) center was explored through detailed magneto-structural investigation using variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, and spectroelectrochemical studies, along with theoretical calculations.

Two new cis-diiodidoplatinum(II) complexes involving bidentate 1,3,4-thiadiazole-based ligands interacted effectively with CT-DNA. Within a panel of human cancer cell lines, only the HepG2 and A549 cells were sensitive towards the studied complexes, but their in vitro cytotoxicity was lower than determined for the reference drug cisplatin.

Three new hydrazone switches were investigated for their utilization as new MRI contrast agents. The structural changes induced by pH change influenced the¹⁹F NMR spectra of these molecules significantly. Thus, these compounds represent a new class of smart MRI contrast agents.

We investigated the crystal structure and magnetism of three Co(II) complexes with neocuproine and carboxylate ligands. We revealed that even by using very simple ligands we can achieve high trigonality of the coordination polyhedron needed for the stabilization of double degenerate ground state and thus, observation of large axial anisotropy.

This work is dedicated to the synthesis, characterization and radical scavenging activity of two copper(II) complexes containing 2-(1H-tetrazol-5-yl)-1H-indole and 1,10-phenanthroline as ligands. Special attention is given to the descriptions of crystal structures of tetrazole-based ligand  as well as copper(II) complexes. The ability of complexes to scavenge free radicals was confirmed and quantified spectrophotometrically by scavenging of model radical DPPH. In order to elucidate the possible scavenging mechanism, DFT calculations were performed and revealed that the main mechanism is single electron transfer (SET), during which Cu(II) is reduced to Cu(I).

An innovative three-component biopolymer film based on chitosan (CHIT), furcellaran (FUR) and a gelatin hydrolysate from carp skins (Cyprinus carpio) (HGEL) was developed. The structure and morphology were characterised using the Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM). The FT-IR test showed no changes in the matrix after the addition of HGEL, which indicates that the film components were compatible. Based on the obtained AFM results, it was found that the addition of HGEL caused the formation of grooves and cracks on the surface of the film (reduction by ~21%). The addition of HGEL improved the antioxidant activity of the film (improvement by up to 2.318% and 444% of DPPH and FRAP power, respectively). Due to their properties, the tested films were used as active materials in the preservation of American blueberries. In the active films, the blueberries lost mass quickly compared to the synthetic film and were characterised by higher phenol content. The results obtained in this study create the opportunity to use the designed CHIT–FUR films in developing biodegradable packaging materials for food protection, but it is necessary to test their effectiveness on other food products.

In this work, three structurally new pyridine-based macrocyclic ligands, two containing one pyridine pendant arm (L₁ and L₂) and one containing piperazine rings in the macrocyclic scaffold (L₃), with an increasing size of the macrocycle from 12-, 14- to 30-membered ring for L₁–L₃ were synthesized and characterized. A series of three Ni(II) complexes with all these ligands was prepared. Based on the results of X-ray structural analysis, the prepared complexes were found as six-coordinate with octahedral geometry (coordination spheres were completed by solvent molecule(s)). The values of effective magnetic moments, determined by the Evans method in solution, well corresponded to the theoretical spin-only values.

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for AgNPs+KB and 440.8 nm for AgNPs+PE was observed via spectral analysis of UV absorbance. In this study, double-layered biopolymer films (FUR/CHIT+HGEL) with AgNPs incorporated in KB solution (AgNPs+KB) and AgNPs in PE solution (AgNPs+PE), were successfully prepared using the casting method. The SEM, XRD, zeta potential and size analyses confirmed the presence of AgNP in the films. The addition of AgNPs in plant extracts improved antimicrobial and antioxidant activity and thermal stability, whereas WVTR experienced a decrease. The nanocomposite films’ orange-brown colour may aid in the protection of food products against UV rays. The composite films demonstrated antibacterial activity against food-borne pathogens and may offer potential in food packaging applications.

A series of new complexes containing vanadium and lanthanides has been prepared, and it was revealed, that two reported complexes are the first single-molecule magnets among this class of V(IV) – Ln(III) compounds. A number of different theoretical methods for determining magnetic exchange in lanthanide containing compounds was utilized and compared in this publication.

There is a serious need to develop and test new biodegradable packaging which could at least partially replace petroleum-based materials. Therefore, the objective of this work was to examine the influence of the recently developed furcellaran nanocomposite film with silver nanoparticles (obtained by an in situ method) on the quality properties of two cheese varieties: a rennet-curd (gouda) and an acid-curd (quark) cheese. The water content, physicochemical properties, microbiological and organoleptic quality of cheese, and migration of silver nanoparticles were examined. The film improved the microbiological quality of cheeses during storage. Consequently, it is worth continuing research for the improvement of this film in order to enable its use in everyday life.

The present study deals with the in vitro evaluation of the potential use of coordination compound-based zinc oxide (ZnO) nanoparticles (NPs) for the treatment of triple negative breast cancer cells (TNBrCa). Prepared by reacting zinc carboxylates and hexamethylenetetramine, 4 distinct coordination compounds were further subjected to two modes of conversion into ZnO NPs - ultrasonication with oleic acid or heating of pure precursors in an air atmosphere. The resulting ZnO NPs provide distinct morphological features, size, biocompatibility, and selective cytotoxicity toward TNBrCa cells. The crucial properties of ZnO NPs seem to be their morphology, size, and zinc content. The ZnO NPs with the most preferential values of all three properties show great promise for a future potential use in the therapy of TNBrCa.

In vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB(R)), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated.

The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB(R) and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.

The article describes the preparation, structural and magnetic properties of two tetranuclear ferrous complexes – optical isomers, which are both showing the spin crossover magnetic bistability. The oustdanding results of this work are based on the controlling of the spin crossover properties by the optical isomerism. A bis-tridentate N-donor ligand has been used for the preparation of both ferrous tetranuclear [2+2] grids, where the used ligand can coordinate in the Lambda or Delta configuration. The magnetic properties investigation revealed that both optical isomers are showing almost identical thermal spin crossover, but they show the differences in the photoinduced spin transition properties.

In order to prepare a multifunctional magnetic material combining spin crossover together with single-molecular magnetism, co-crystallization of Fe(II) and Co(II) complexes of the pyridine derivative of cyclam (Py₂-C = 1,8-bis(pyridin-2-ylmethyl)-1,4,8,11-tetraazacyclotetradecane) was performed. Complexes with the general formula [M^II(Py₂-C)](ClO₄)₂·H₂O (M^II = Fe (1), Co (2) or Fe_0.4Co_0.6 (3)) were prepared and thoroughly characterized. Based on X-ray molecular structures, they formed octahedral complexes with cis-arrangement of the coordinated pyridine moieties. Magnetic data revealed that the Fe(II) complex 1 shows complete SCO with the transition temperature T_1/2 = 141 K, which is preserved also in the mixed Fe/Co system 3 (T_1/2 = 128 K). Co(II) complex 2 behaves as a field-induced single-molecule magnet as well as the mixed system 3 with a direct and phonon bottleneck relaxation process, respectively.

In this paper, we report on synthesis and crystal structure of three decanuclear Co^II/III-Ln^III complexes, which were prepared from heptanuclear precursors by solvent induced aggregation. It was revealed that the aggregation was induced by removal of the methoxido bridging ligands, which were substituted by hydroxido ligands.

In this work, we studied the solution behaviour of two half-sandwich Ru(II) and Ir(III) complexes bearing the ester-functionalized 2,2′-bipyridine-based ligand. It was proved that the nature of ester substituent (acetate vs. dichloroacetate) affects the in-solution stability of the ester bond. The experiments performed in the presence of porcine liver esterase (PLE) indicated that although free ester-based ligand was readily metabolized by PLE (acetate release was observed), both complexes containing this ligand were not cleaved by PLE, meaning distinctly different affinity of the used enzyme to the substrate (ligand) when involved in the studied complexes.

In this work, three Fe(II) coordination compounds were investigated, while by examining the magnetic properties of [Fe(L2)₂(NCS)₂]_n (3) (L2 = 2,5-diethynylpyridinyl-3,4- ethylenedioxythiophene) it was confirmed that the change in spin state is caused by the change in temperature, i.e. it is a spin crossover compound. Photomagnetic experiments confirmed the possibility of switching the spin state even by exposure to light. The study was also supported by theoretical calculations such as DFT, TD-DFT and CASSCF explaining the magnetic and spectroscopic properties of these substances.

In this work, we investigated the solution behaviour of biologically prospective complex cis-[PtI₂(NH₃)(pic)] (pic = 2-methylpyridine), a diiodido analogue of clinically studied Pt-based drug picoplatin (cis-[PtCl₂(NH₃)(pic)]). We proved both experimentally and theoretically that cis‑[PtI₂(NH₃)(pic)] is, in contrast to picoplatin, unstable in solution, where it undergoes several processes, including the release of its N-donor pic ligand. This observation complicates the cytotoxicity testing of this Pt(II) diiodido complex.

In this work, 3 structurally new ligands L1-L3 derived from a 17-membered macrocyclic ligand with pyridine and piperazine group and their manganese complexes were prepared. Based on the results of X-ray structural analysis, the prepared complexes were found as seven-coordinate with close to the pentagonal bipyramidal geometry. The Mn-N_aliphatic bond distances in the equatorial plane were significantly lengthened up to 2.61Å.

In this work, the magnetic properties of two hexanuclear coordination compounds [Gd₂Ni₆L₄(μ₃-OH)₆(μ-OH)₂(CH₃CO₂)₂(μ-H₂O)₂(H₂O)₃(MeOH)]·8H₂O (1) and [Dy₂Ni₆L₄(μ₃-OH)₄(μ-Cl)₂Cl₄(H₂O)₂(MeOH)₂]·2MeOH·4H₂O (2) prepared with the same ligand - Schiff base H₂L = 2 - {[(2-hydroxy-3-methoxybenzyl) imino] methyl} phenol, were investigated. Inspection of the magnetic properties revealed a dominant ferromagnetic exchange interaction in compound 1 and compound 2 was identified as a single molecule magnet. The study was supported by theoretical calculations such as DFT and CASSCF leading to the elucidation of exchange interactions and magnetic anisotropy in these complexes.

In this review, multinuclear biologically active complexes derived from half-sandwich ruthenium(II), rhodium (III), osmium(II) and iridium(III) arene moieties have been reported. Besides homometallic Ru, Rh, Os and Ir complexes, heterometallic compounds containing the mentioned platinum metals in combination with other d-block elements are discussed as well. Special attention was paid to the comparison of structurally similar analogues differing in the number or type of metal centres.

Herein, we report on investigations of magnetic, spectroscopic and electrochemical properties of two Co(II) coordination compounds with N,N′-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane macrocyclic ligand. Complex 1 exhibits a high-spin (S = 3/2) state of cobalt(II) with a large magnetic anisotropy. Interestingly, complex 2 exhibits reversible spin-state switching (T_1/2 = 321 K).

A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water-retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant S. aureus and S. epidermidis.

The copper(II) complexes of general formula [Cu(GL)(Cl)] (1–3, G = OMe, H and NO₂, respectively), bearing tridentate Schiff base ligands (GL⁻) and a chloride as a fourth labile one, are here reported. The Schiff bases derive from the monocondensation of ethylenediamine and substituted salicylaldehyde, where the electronic properties are modulated by the releasing or withdrawing power of the G group. The compounds were structurally characterized through single crystal Synchrotron X-ray diffraction experiments in the solid state. In vitro tests on cell viability were conducted on malignant cell lines. All compounds were capable of formation of intracellular reactive oxygen species and DNA intercalation. This is especially effective for 3 (NO₂), which revealed the highest anticancer activity against malignant triple-negative breast cancer MDA-MB-231 cells.

Herein, we report on investigations of magnetic and spectroscopic properties of three heterobimetallic Fe(II)–Co(II) coordination compounds based on the tetracoordinate {CoP₂X₂} core encapsulated by dppf metalloligand, where X = Cl (1), Br (2), I (3), dppf = 1,1′-ferrocenediyl -bis(diphenylphosphine). The analysis of static magnetic data has revealed the presence of axial magnetic anisotropy in compounds (1) and (2) and this was further confirmed by high-frequency electron spin resonance (HF-ESR) spectroscopy. Dynamic magnetic data confirmed that (1) and (2) behave as field-induced Single-Ion Magnets (SIMs). Together with bulk studies, we have also tested the possibility of depositing (2) as thick films on Au(111), glass, and polymeric acetate by drop-casting as well as thermal sublimation, a key aspect for the development of future devices embedding these magnetic objects.

The 17-membered piperazine-based macrocyclic ligand L_diProp (1,5,13,17,22-pentaazatricyclo[15.2.2.17,11]docosa-7,9,11(22)-triene) was resynthesized in high yield with help of linear pump. Its Mn(II), Fe(II), Co(II) and Ni(II) complexes of general formula [MnL_diProp(ClO₄)₂] (1), [FeL_diProp(CH₃CN)](ClO₄)₂ (2), [CoL_diProp(CH₃CN)](ClO₄)₂ (3), [NiL_diProp](ClO₄)₂ (4) were prepared and thoroughly characterized. X-ray diffraction analysis confirmed that Mn(II) complex 1 has capped trigonal prismatic geometry with coordination number seven, Fe(II) and Co(II) complexes 2 and 3 are trigonal prismatic with coordination number six and Ni(II) complex 4 has square pyramidal geometry with coordination number five. The decrease of coordination number is accompanied by a shortening of M–N distances and an increase of torsion of piperazine ring from the equatorial plane. Magnetic measurement reveal moderate for 4 and rather large magnetic anisotropy for 2 and 3 (axial zero-field splitting parameter D(Ni) = 9.0 cm^–1, D(Fe) = –14.4 cm^–1, D(Co) = –25.8 cm^–1, together with rather high rhombicity). Co(II) complex 3 behaves as field-induced SMM with a combination of Raman and direct or Orbach and direct relaxation mechanisms. Obtained magnetic data were extensively supported by theoretical CASSCF calculations. The flexibility and rather large 17-membered macrocyclic cavity of ligand L_diProp could be responsible for the variation of coordination numbers and geometries for investigated late-first row transition metals.