Structural characteristics are reported for two thio-ether-ketones, Dtdpe and Mtdp [2-({2-[(2-oxo-2-phenyl-eth-yl)sulfan-yl]eth-yl}sulfan-yl)-1-phenyl-ethan-1-one, C18H18O2S2, and 2-[(2-oxo-2-phenyl-eth-yl)sulfan-yl]-1-phenyl-ethan-1-one, C16H14O2S], and for related derivatives, the bis-(pyridyl-hydrazones) Dhpk and Prpsb [2-((2E)-2-{(2Z)-2-phenyl-2-[2-(pyridin-2-yl)hydrazin-1-yl-idene]ethyl-idene}hydrazin-1-yl)pyridine, C18H16N6, and 2-[(2Z,12Z)-3,12-diphenyl-14-(pyridin-2-yl)-5,10-di-thia-1,2,13,14-tetra-aza-tetra-deca-2,12-dien-1-yl]pyridine, C30H32N6S2], as well as for the macrocyclic thio-carbohydrazide derivative Ctrsp [(3E,8Z)-3,9-dimethyl-1,11-di-thia-4,5,7,8-tetra-aza-cyclo-tetra-deca-3,8-diene-6-thione, C10H18N4S3]. Three of the five compounds exhibit conformational enanti-omerism in the solid state. The occurrence of intra- and inter-molecular hydrogen bonding is commented upon through quantum mechanical (DFT) calculations. Weak C-H⋯S inter-actions are noted, while stronger N-H⋯N and N-H⋯S hydrogen bridges are delineated.

Two complexes {[GdCu5(GlyHA)5(H2O)7Cr(C2O4)(3)]11.02H2O}n (1) and {{[GdCu5(GlyHA)5(H2O)6]mu 2-[Cu(C2O4)(2)(H2O)]}2 mu 4-[Cu(C2O4)2]15.8H(2)O}n (2), were obtained as outcomes of the reactions between the cationic hexanuclear {GdCu5(GlyHA)5}3+ 15-metallacrown-5 complex (where GlyHA2- = glycinehydroxamate) and the anionic oxalate complexes K3[Cr(C2O4)3] or K2[Cu(C2O4)2]. Both 1 and 2 possess polymeric 1D-chain structures according to X-ray structural analysis. As a consequence of the geometric orientations of the donor atoms in the oxalates from [Cr(C2O4)3]3-, the Cu5 mean planes of neighboring 15-metallacrown-5 units {GdCu5(GlyHA)5}3+ are angled at 75.5 degrees to each other, which leads to formation of a zig-zag motif in the 1D-chains of complex 1. The centrosymmetric complex 2 contains two structurally different bis(oxalato)cuprate anions mu 2-[Cu(C2O4)2(H2O)]2-, for one of which, coordination to two adjacent {GdCu5(GlyHA)5}3+ units leads to formation of linear 1D-chains in 2, while the second type, mu 4-[Cu(C2O4)(2)]2-, is coordinated to four {GdCu5(GlyHA)5}3+ units, causing the cross-linking of single 1D-chains into a double-chain 1D coordination polymer. Studies of chi MT vs. T data for 1 and 2 in a 2-300 K temperature range revealed the presence of both ferromagnetic and antiferromagnetic interactions amongst paramagnetic centres. The experimental chi MT vs. T data for 1 were fitted using a model which takes into account exchange interactions between adjacent copper(ii) ions, the Gd-Cu exchange interactions within {GdCu5(GlyHA)5}3+ units and additionally Gd-Cr exchange interactions. Fitting of the chi MT vs. T data for 2 was not possible, since coordination of mu 4-[Cu(C2O4)(2)]2- to {GdCu5(GlyHA)5}3+ led to the non-equivalence of several Cu-Cu exchange interactions within the metallacrown units and hence a superfluity of fittable parameters. Complexes 1 and 2 are the first examples of 15-metallacrown-5 complexes demonstrating a magnetocaloric effect (-Delta SM at 13 T reaches 24.26 J K-1 kg-1 at 5 K and 19.14 J K-1 kg-1 at 4 K for 1 and 2, respectively).

A new mononuclear complex, pentaaqua(cucurbit[6]uril-κ2O,O′)(nitrato-κ2O,O′)praseodymium(III) dinitrate 9.56-hydrate, [Pr(NO3)(CB6)(H2O)5](NO3)2·9.56H2O (1), was obtained as outcome of the hydrothermal reaction between the macrocyclic ligand cucurbit[6]uril (CB6, C36H36N24O12) with a tenfold excess of Pr(NO3)3·6H2O. Complex 1 crystallizes in the P21/n space group with two crystallographically independent but chemically identical [Pr(CB6)(NO3)(H2O)5]2+ complex cations, four nitrate counter-anions and 19.12 interstitial water molecules per asymmetric unit. The nonacoordinated PrIII in 1 are located in the PrO9 coordination environment formed by two carbonyl O atoms from bidentate cucurbit[6]uril units, two oxygen atoms from the bidentate nitrate anion and five water molecules. Considering the differences in Pr—O bond distances and O—Pr—O angles in the coordination spheres, the coordination polyhedrons of the two PrIII atoms can be described as distorted spherical capped square antiprismatic and muffin polyhedral.

The complex {Na-2(H2O)(8)[GdCu5(GlyHA)(5)(H2O)(4)L](2)}L-2 & sdot; 2.5DMF & sdot; 10.5H(2)O (1, where GlyHA(2-)= glycinehydroxamate, L2-= 4,4 '-bis(2-sulfonatostyryl)biphenyl) was obtained as the outcome of the metathesis reaction of previously reported [GdCu5(GlyHA)(5)(CO3)(NO3)(H2O)(5)] & sdot; 3.5H(2)O with an excess of the disulfonate's sodium salt. X-Ray analysis of 1 shows a dimeric structure in which 15-metallacrown-5 units {GdCu5}(3+) are arranged in an "edge-to-edge" manner by way of two linking disulfonates, L2-. Magnetic studies of polycrystalline 1 over a temperature range of 2-300 K revealed both Gd-Cu ferromagnetic and Cu-Cu antiferromagnetic interactions within the metallacrown unit. Experimental chi T-M vs. T data for 1 were fitted using different theoretical models. A two-J model, which takes into account both exchange interactions between adjacent copper(II) ions and the Gd-Cu exchange interactions allows fitting of the chi T-M vs. T data in the whole temperature range. The values obtained for the exchange parameters are in accord with previously reported parameters for Ln(III)-Cu(II) 15-metallacrowns-5. The 240 GHz powder EPR spectra for 1 were recorded between 30 and 150 K.

A new series of hexadentate thioether-containing ligands was designed. Five nickel(II) dicationic pseudo-octahedral complexes synthesised with them revealed different degrees of deviation from ideal geometry. The electronic absorption spectra confirm the formation of high-spin octahedral [NiN4S2]2+ chromophores with a large covalency typical for Ni(II) thioether complexes. DFT calculations help assign the chelating agent transitions, and support the Ni(II) high-spin ground state assignments, while suggesting that the SOMOs have mainly ligand character. The electrochemical behaviour of the complexes is consistent with irreversible n= 1 redox processes around −1.0 V, formally assignable to the Ni(II)/Ni(I) couple. Ligand reduction and large current augmentation due to catalytic H2 production are also observed in this region.

The phenomenon of single ion magnetism in Ln(3+) coordination compounds and the principles of their rational design are considered. The influence of electronic and chemical structure, as well as the symmetry of the coordination sphere on the value of the energy barrier of magnetic anisotropy, is highlighted. Based on the analysis of the available data in the literature, it is concluded that further efforts in the design of single ion magnets should focus on the development of coordination compounds Dy3 + and Tb3 + with high axiality, in which the strength of the bond between central metal ion and ligands in the apical position far exceeds the appropriate values for ligands in the equatorial plane.

A series of new tris(pyrazolyl)borate (Tp(-)) and tris(2-pyridylpyrazolyl)borate (Tp(Py-)) Eu3+, Gd3+, Tb3+ and Dy3+ complexes with the dianionic ligand 4,4 '-bis(2-sulfonatostyryl)biphenyl (Ssp(2-), a widely used fluorescent whitener) were synthesized and their luminescence properties were studied. The Gd3+, Tb3+ and Dy3+ compounds possess only ligand-centered emission, arising from the Ssp(2-) ligand, with quantum yields of up to 60 %. While the emission centers in these complexes are similar, the positions of the luminescence maxima, the emission quantum yields, and the lifetimes change in the order [(Tp(2)Ln)(2)Ssp]<[(Tp(Py)LnSsp)(2)]<[Ln(2)Ssp(3)](n). Among the complexes studied, Eu3+-centered emission was observed for only [(Tp(2)Eu)(2)Ssp]. In this compound, Tp(-) plays the role of an antenna ligand for Eu3+-radiation, though the quantum yield is only 5 %.

A new binuclear copper(II) complex Cu2(Piv)4(L)2, where Piv– = pivalate, L = 2,6-di-tert-butyl-4-(3,5-bis(4-pyridyl)pyridyl)phenol, was synthesized, and its molecular and crysral structures were determined at temperatures of 160, 173, and 296 K (CIF files CCDC no. 2144104, 2144105, and 2144106, respectively). Cyclic voltammetry measurements revealed three irreversible oxidation processes in the potential range of 0.5–1.2 V versus Fc+/Fc. Analysis of the temperature dependence of the magnetic susceptibility of Cu2(Piv)4(L)2 showed that antiferromagnetic interactions of Cu2+ ions predominate in the complex. It was found that the oxidation of Cu2(Piv)4(L)2 upon grinding with PbO2 or treatment of a solid sample with an aqueous solution of K3[Fe(CN)6] affords long-lived phenoxyl radical, which can be detected by ESR spectroscopy.

It was shown that the emission intensity of (TpPyTb)2pma and (TpPyEu)2pma (TpPy– = tris(3-(2′-pyridyl)- pyrazolyl)borate, pma4– = tetraanion of pyromellitic acid) solutions decreases with the increasing concentration of N-nitrosamines with the luminescence quenching efficiency up to 92%. This quenching is due to the primary inner filter effect, i.e. the partial absorption of the exciting light by N-nitrosamines. It was suggested that the dependence of emission quenching efficiency of the complexes on the concentration of N-nitrosamines can potentially be used for estimation of their amount in solution by fluorescence spectroscopy.

Представлено результати розробки магнітної та магнітно-люмінесцентної рідини на основі нанорозмірних частинок CoFe 2 O 4 , а також композитів магнітних наночастинок CoFe 2 O 4 та Fe 3 O 4 з органічними полімерами.Показано, що використання рідини на основі CoFe 2 O 4 для магнітної дефектоскопії дозволяє візуалізувати дефекти з шириною розкриття щонайменше 1,2 мкм.Додавання люмінесцентного барвника до магнітної рідини дає можливість одержати магнітно-люмінесцентний матеріал, використання якого дозволяє проявляти дефекти завдяки втягуванню усієї рідини в магнітне поле.Запропоновано простий спосіб приготування композицій для одержання реплік для методу магнітно-порошкової дефектоскопії, який полягає у створенні магнітних рідин Fe 3 O 4

A series of tris(pyrazolyl)borate mono-, di- and trinuclear complexes, [Tp2Ln]nX (Ln = Eu, Tb, Gd, Dy, Xn- = various mono-, bis- and tris(β-diketonates) has been prepared. The Tb3+ and Dy3+ complexes are luminescent single molecular magnets (SMM) and exhibit luminescence quantum efficiencies up to 73% for the Tb3+ and 4.4% for the Dy3+ compounds. Similar Eu3+ complexes display bright emission only at lower temperatures. The Dy3+ and Tb3+ complexes possess SMM behavior in a non-zero dc field at low temperatures, while the polynuclear Dy3+ complexes also show slow magnetic relaxation even in zero dc field up to 8 K. Ueff-values determined from dynamic magnetic measurements were up to 31 and 6 cm-1 for the Dy3+ and Tb3+ complexes, respectively. It was found that within a series of Dy3+ and Tb3+ compounds, Ueff and luminescence quantum yields decreased with increasing nuclearity of the compounds and a shortening of the intramolecular Ln-Ln distance. ΔOrbach-values estimated from low-temperature luminescence spectra were significantly higher than those obtained from ac magnetic data, which may be due to involvement of additional processes in the relaxation mechanism (quantum tunneling, Raman, direct) reducing the energy barrier. Some of the Tb3+-compounds also display metal-centred electroluminescence, giving them potential as emitting layers in LEDs.

Theoretical aspects of the magnetocaloric effect of coordination compounds, which hold promise for the design of new cooling agents termed “molecular refrigerators,” is examined. Due to special features of the electronic structure of polynuclear gadolinium(III) complexes, these compounds hold promise for use as refrigerating materials for achieving subhelium temperatures. Analysis of the literature suggests that further efforts on the design of molecular cooling agents should be concentrated on the development of molecular polynuclear scaffolds with gadolinium ions bound to a number of low-molecular-weight bridging ligands.

The modern concepts underlying the control of luminescence characteristics (quantum yield, intensity, emission color) of lanthanide coordination compounds are analyzed. The influence of the electronic structure of ligands and ions of 4f elements on the luminescent properties of these metal complexes is examined in detail. Approaches for changing the quantum yield values, emission intensity and color are proposed both by the directed design of the coordination sphere of lanthanide ions and the composition of compounds, and by using external stimuli (temperature, wavelength of exciting light).

A method has been developed for obtaining ferrofluids including luminescent ferrofluids derived from CoFe2O4 nanoparticles. The use of these materials in magnetic particle inspection permits the visualization of microdefects. In contrast to magnetic suspensions, ferrofluids are completely included in the area of defects such that the defect image has greater contrast and volume.

The luminescence of coordination polymers of Pr3+, Nd3+, and Lu3+ with tetrafluoroterephthalate and camphorate, [Ln(2)(Fbdc)(3)(DMF)(2)(H2O)](2) (Ln = Pr, Nd, Lu) and [Ln(2)(Camph)(2)(NO3)(2)(MeOH)](4) (Ln = Pr, Nd, Lu), was studied. Ligand-centered and/or metal-centered emissions appear, which depend on the excitation wavelength, ultimately allowing the emitted light color to be adjusted. Low-efficiency ligand-to-metal energy transfer leads to a difference between the excitation spectra of the tetrafluoroterephthalate-and camphorate-Pr3+ compounds, arising from a primary filtering effect on the ligand-centered excitation, by Pr3+ absorption. A secondary inner filter effect significantly changes the shape of the luminescence band, allowing a wide variation in the emission color, producing, for instance, a purple color, which is not the normal spectral emission. The low-efficiency energy transfer renders tetrafluoroterephthalate and camphorate ineffective as traditional "antenna" ligands for Pr3+ and Nd3+.