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Reactions of Zn(NO3)2·6H2O, 2-iodobenzoic acid (2-IBA), and 4-ethyl- or 3-chloropyridine result in the formation of binuclear neutral complexes [Zn2(2-IBA)4L2] (L = 3-ClPy (1), 4-EtPy (2)) whose structures are analyzed by X-ray crystallography. The structure of 2 has specific noncovalent I⋯I interactions.

By the reaction of a rigid π-conjugated H4L linker (5,5′-(1,3,6,8-tetraoxobenzo[lmn][3],[8]phenanthroline-2-7-diyl)bis-1,3-benzenedicarboxylic acid), Cu(NO3)2, and N-donor auxiliary linkers, two new Cu-based coordination polymers (CPs), namely {[Cu(L)0.5(1,4-bib)(H2O)2]·0.5H2O}n (1) and {[Cu(H2L)(4,4′-bibp)(H2O)2]}n (2) {1,4-bib = 1,4-bis(1-imidazolyl)benzene, 4,4′-bibp = 4,4′-bis(imidazolyl)biphenyl} are synthesized under solvothermal conditions and characterized. Furthermore, the protective effect of compounds 1 and 2 on the sepsis mice model is evaluated and the related mechanism is explored. Firstly, the CFU counting assay is performed to detect the bactericidal effect of compounds 1 and 2 in vivo. Then, the ELISA assay is conducted to measure the release of interleukin-1β (IL-1β) and interleukin-6 (IL-6) into the plasma after treatment with the compounds.

The Co2+–triglycine–L-histidine system is studied in an aqueous solution at Т = 298.15 K (KNO3) via potentiometry and calorimetry. The formation of mixed-ligand CoL2Y− complex is established, and the standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°) of the complexation reaction are determined. A structure is proposed for this complex.

Two mixed-ligand coordination polymers with the chemical formulae {[Cu3(Hdpc)2(tib)2(H2O)2]·2H2O)}n (1, H3dpc = 2,6-di(4-carboxylphenyl)pyridine-4-carboxylic acid, tib = 1,3,5-tris(1-imidazolyl)benzene)) and [Cu(trans-chda)2(bimb)2·2H2O]n (2, H2chda = 1,4-cyclohexane(dicarboxylic)acid, bimb = 1,4-bis((1H-1,2,4-triazol-1-yl)methyl)benzene) are successfully prepared by the reaction of Cu(NO3)2·3H2O with different O-donor carboxylic acid and N-donor co-ligands under the solvothermal conditions. Furthermore, the treatment effect of the two compounds on the acute pancreatitis is evaluated in the biological experiment. Firstly, RT-PCR is performed to measure the relative expression level of the key genes of E. coli. Moreover, the inflammatory levels of the patients are evaluated by the ELISA detection of inflammatory cytokines, IL-1β, and TNF-α.

The spectral-luminescent properties of europium(III) complexes with o-methoxybenzoic acid and phosphorus-containing neutral ligands with an island structure and the compositions Eu(MOBA)3 · 3H2O and Eu(MOBA)3 · L, where MOBA is o-methoxybenzoic acid and L is hmpa (hexamethylphosphortriamide, tppo (triphenylphosphinoxide), and Et6pa (hexaethylphosphortriamide), are studied. It is found that the excitation energy transfer to the europium ion occurs from the levels of both o-methoxybenzoic acid and phosphorus-containing neutral ligands. The electronic absorption and luminescence excitation spectra, as well as the Stark structure of the 5D0−7Fj ( j = 0–2) electronic transitions in the luminescence spectra of mixed-ligand complexes of europium(III) o-methoxybenzoates, are analyzed. The highest luminescence intensity is demonstrated by europium(III) methoxybenzoate with triphenylphosphinoxide.

Luminescent coordination mixed-ligand compounds of europium(III) with ortho-methoxybenzoic acid and phosphorus-containing neutral ligands of the isle-like structure Eu(MOBA)3 · 3H2O and Eu(MOBA)3 · L have been synthesized. MOBA—ortho-methoxybenzoic acid, L—hmpa (hexamethylphosphotriamide), tppo (triphenylphosphinoxide), Et6pa (hexaethylphosphotriamide). Thermal properties of the complex mixed-ligand compounds of europium(III) have been investigated. It has been shown that thermolysis results in the splitting of a neutral ligand molecule proceeding within one stage along with an endothermic effect. The complex compound appeared to be stable up to 280°C. The composition and structure of the synthesized complexes have been established. Based on the IR spectroscopy data, it has been demonstrated that in ortho-methoxybenzoates of europium(III) ortho-methoxybenzoic acid is coordinated to a europium(III) ion bidentately.

The Cu2+–triglycine–L-histidine system was studied by potentiometry and calorimetry in an aqueous solution at T = 298.15 K (KNO3). Mixed-ligand CuLY and CuLHY+ complexes formed in the system. The standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°) of their formation reactions were determined. The possible structures of the mixed-ligand complexes were given.

Interaction of iridium(III) nitro-aqua complexes with 1,10-phenanthroline is studied. Complex anions [Ir(phen)(NO2)4]− and [Ir(phen)(OH)(NO2)3]− are isolated in the solid phase. The complex Na[Ir(phen)(NO2)4](phen)(H2O) is structurally characterized for the first time. Crystallographic data: $$a = 8.0752(5)\acute{\overset{\circ}{\mathrm{A}}}$$ , $$b = 11.690(7)\acute{\overset{\circ}{\mathrm{A}}}$$ , $$c = 14.012(7)\acute{\overset{\circ}{\mathrm{A}}}$$ , α = 105.55(2)°, β = 91,99(2)°, γ = 103,71(2)° space group P-1, Z = 2, ρcalc = 1,936 g/cm3. The coordination sphere of the iridium atom has a distorted octahedral geometry. The obtained structure contains an island motif consisting of the pairs of complex anions [Ir(phen)(NO2)4]− linked to each other by sodium cations.

Terpolymers with a molecular weight of 65 and 13 kDa containing 90 mol % of N-vinylpyrrolidone, 7 mol % of N-vinylformamide, and 3 mol % of N-vinyliminodiacetic acid units have been synthesized. Diethyldithiocarbamate and benzyldithiocarbamate have been used as coligands. The mixed-ligand complexation with Ga3+ ion has been studied by HPLC. The composition and structure of the resulting metal–polymer complexes have been determined by exclusion chromatography and spectral (IR, 1H NMR) data.

The formation of mixed ligand complexes in HgEdta2−–L systems (L = Asp2−, Glu2−, Ida2−, Nta3−, and Edta4−) is studied via calorimetry, pH-metry, and NMR spectroscopy. The thermodynamic parameters (log K, ΔrG°, ΔrH, ΔrS) of complexation reactions are determined at T = 298.15 K and ionic strength I = 0.5(KNO3). The most plausible mechanism of ligand coordination within a mixed-ligand complex is discussed.

The quantum chemical modeling (DFT UTPSSh/6-311++G(d,p)) of the binuclear homo- and heterometallic Fe and Co complexes based on the 5,6-bis(salicylideneimino)-1,10-phenanthroline ligand and two bipyridyl molecules is performed. The magnetic properties of these compounds can be switched due to the thermally induced spin-crossover occurring at the cobalt ions. The predicted energetic and magnetic characteristics of isomers of the studied systems allow one to consider them as promising molecular switches.

Mixed-ligand nitrile- and carbonyl-isocyanide complexes of platinum(II) trans-[PtCl2(NCEt)CNXyl] and trans-[PtCl2(CO)CNXyl] (Xyl = 2,6-Me2C6H3) have been prepared for the first time. The compounds have been characterized by mass spectrometry, IR and NMR spectroscopy. Reactivity of the prepared complexes towards N-nucleophiles has been studied using the reaction with p-toluenesulfonyl hydrazide as the example.

The Ni2+–triglycine–L-histidine system is studied by potentiometric and calorimetric means in aqueous solutions at Т = 298.15 K (KNO3). The formation of mixed ligand complex NiLY is registered, and standard thermodynamic characteristics (ΔrH°, ΔrG°, ΔrS°) of its formation are determined. A structure of the complex is proposed.

The formation of mixed-ligand complexes in the M(II)–Nta, Ida–L (M = Cu(II), Ni, Zn, Co(II), L = Ser, Thr, Asp, Arg, Asn) systems, where Ida and Nta are the residues of iminodiacetic and nitrilotriacetic acids, respectively, is studied using pH measurements, calorimetry and spectrophotometry. The thermodynamic parameters (logK, ΔrG0, ΔrH, ΔrS) of their formation at 298.15 K and ionic strength I = 0.5 (KNO3) are determined. The most likely scenario of amino acid residue coordination in the composition of mixed complexes is discussed.

A mixed ligand complex of Ni(II) with 3-imidazoline nitroxide and iso-propanol [NiL2(i-C3H7OH)2] is sensitive to atmospheric moisture. It is determined that at a high humidity, the air contacts with the mother solution of the compound in iso-propanol with the precipitated [NiL2(i-C3H7OH)2] crystals leads to their spontaneous transformation into [NiL2(H2O)]·i-C3H7OH crystals whose structure is described in the present paper.

The formation of mixed-ligand complexes in the M(II)–Nta and Ida–L systems (M = Co, Zn; L = His, Orn, Lys, Gly, Im, en), where Ida and Nta are the residues of iminodiacetic and nitrilotriacetic acids, was studied by pH-metry, calorimetry, and NMR spectroscopy. The thermodynamic parameters (logK, Δ r G0, Δ r H, Δ r S) of formation for these complexes were determined at 298.15 K and an ionic strength I = 0.5 (KNO3). The most probable pattern of coordination between a complexone and an amino acid in mixed-ligand complexes was revealed.

Solid phases of the [Eu(Phen)(i-Bu2PS2)2(NO3)]–[Tb(Phen)(i-Bu2PS2)2(NO3)] binary system are synthesized. The results of X-ray diffraction phase analysis and photoluminescence measurements allow the synthesized isostructural phases to be classed with substitutional solid solutions. The photoluminescence measurements revealed Tb(III)→Eu(III) energy transfer which induces Eu3+ luminescence.

Single crystals of a mixed-ligand cadmium complex of the composition Cd(PHBA)2(MEA) 2 are grown from the solution of Cd(CH3OO)2, p-hydroxybenzoic acid (PHBA) and monoethanolamine (MEA) in aqueous ethanol. The crystallographic data are as follows: a = 11.6400(2) A, b = 10.1363(1) A, c = 16.6296(2) A, β = 93.937(1)°, space group I2/a, V = 1957.44(5) A3, Z = 4. In the complex molecule located on the twofold axis, ligands of both types are bidentately bound to the cadmium ion having the coordination number 8. In the crystal structure, two H bonds of the O–H•••O type combine complex molecules into layers parallel to the ab plane.

Copper(II), zinc(II), and cadmium(II) mixed-ligand complexes [M(L)(L1)], (M = Cu (I), Cd (III)), [Zn(L)(L1)(H2O)] (II) and [Cd(L)(L2)] (IV)) on the basis of N-(2-{[1-phenyl-3-methyl-5-oxo-1,5-dihydro-4H-pyrazol-4-ylidene)methyl]amino}phenyl)-4-methylbenzenesulfonamide (H2L), 2-amino-1-ethylbenzimidazole (L1), and 2-aminopyrazine (L2) were prepared by electrochemical method. The composition and structure of the obtained compounds were proved by the data of C, H, N, S elemental analysis, IR and 1H NMR spectroscopy (for compounds II–IV), X-ray absorption spectroscopy (for compounds I and II), and magnetochemical measurements (for compound I), photoluminescent properties of complexes II–IV were also studied. The structure of compound II was determined by X-ray diffraction analysis.

The complexation of tungsten(VI) with 2-hydroxy-5-chlorothiophenol in the presence of diphenylguanidine is studied by spectrophotometry. Optimal conditions for the formation and extraction of the complex are determined. It is found that a mixed-ligand complex is formed at pH 5–6. Chloroform and dichloroethane are the best extractants. Some physicochemical characteristics of the mixed-ligand complex are determined; the molar absorption coefficient at 480 nm is 5.6 × 104. The molar ratio of components in the complex is 1: 2: 2.

The reactions of lanthanum acetylacetonate with various phosphorus-containing pesticides, toxic gases, and products of their hydrolysis are modeled by quantum-chemical methods. In the most cases, the enthalpy of substitution for water by organophosphorus compounds is negative. The complexes are studied in solutions using ethyl (diethoxyphosphoryl) acetate as a model compound. The mixed-ligand lanthanide complexes with acylpyrazolones and ethyl (diethoxyphosphoryl) acetate are synthesized. The crystal structure is determined for the samarium complex.

The synthesis and X-ray single crystal study of two mixed-ligand Cu(II) complexes are performed: (CH3C(NCH3)CHC(O)CH3)(CF3C(O)CHC(O)CF3)Cu (1) (space group P21/c, a = 7.0848(12) A, b = 17.854(3) A, c = 11.837(2) A, β = 100.495(6)°, V = 1472.4(4) A3, Z = 4), (CH3C(NC6H5)CHC(O)CH3)· (CF3C(O)CHC(O)CF3)Cu (2) (space group P-1, a = 9.1119(4) A, b = 9.6954(4) A, c = 11.1447(6) A, α = 113.784(2)°, β = 92.383(2)°, γ = 95.402(2)°, V = 893.52(7) A3, Z = 2). The structures are molecular, formed from neutral mixed-ligand copper complexes. The central copper atom has the (3O+N) coordination environment with average Cu-O distances of 1.948 A and Cu-N of 1.932 A; the chelate O-Cu-N angle (average) is 94.0°. In the structures, the complexes are linked into dimeric associates with Cu…Cu distances of 3.197 A (for 1) and 3.246 A (for 2). The volatility of mixed-ligand complexes 1 and 2 is in between of that of the starting homo-ligand complexes.

Based on the 31P NMR data, equilibriums in the [RuNO(NO2)4OHZn(TPPO)3]-Py system are quantitatively described, and equilibrium constants of dissociation of the initial complex and organic ligand substitution are determined. The stability of heterometallic complexes is found to increase in passing from TPPO to pyridine. The mixed ligand [RuNO(NO2)4OHZn(TPPO)2Py] complex is structurally characterized, and it is shown that the TPPO molecule in the trans-position to the μ2-bridging hydroxo group is substituted first.

The luminescent spectral characteristics of neodymium(III) tris- and tetrakis-β-diketonates and β-diketonate acido complexes were investigated. The dependence between the intensity of the luminescence and the composition of the coordination sphere of the complexes was revealed. The most intense luminescence in the IR region possess the neodymium(III) compounds which are the mixed ligand complexes with β-diketones and phosphorus-containing neutral ligands.

We have synthesized Mn(thd)3 (thd = dipivaloylmethane, or 2,2,6,6-tetramethyl-3,5-heptanedione) and evaluated its enthalpy of sublimation (89.0 ± 7.0 kJ/mol) and its saturated vapor pressure as a function of temperature from mass spectrometry data. Exchange reactions between Mn(acac)3 (acac = acetylacetonate, or 2,4-pentanedione) and Mn(thd)3 have been performed using an in situ technique. We have calculated the enthalpies of the exchange reactions and the enthalpies of formation of Mn(acac)2(thd) and Mn(acac)(thd)2 in the vapor phase: −1417.5 ± 15.0 and −1590.6 ± 15.0 kJ/mol, respectively.

The luminescence spectral characteristics of mixed-ligand compounds of ytterbium(III) with cinnamic acid and neutral phosphorus-containing ligands were studied by luminescence spectroscopy. The intensity of luminescence of the compounds was determined. The highest intensity of luminescence was found for the ytterbium(III) compound with triphenylphosphine oxide.

Synthesis was carried out of the new mixed-ligand square-planar platinum(II)complexes {Pt(R2SO)[(-)-S-NOBIN]Cl2}, where (-)-S-NOBIN was S-2-amino-2′-hydroxy-1,1′-binaphthyl (R = Me, Et). The complexes are of interest as catalysts for asymmetrical synthesis. The detailed analysis of NMR, UV, and CD spectra of these compounds was performed. These complexes were established to be a mixture of the corresponding cis- and trans-isomers.

Mixed-ligand complexation of GdEdta− with glycinate, L-glutamate, DL-aspartate, iminodiacetate, and nitrilotriacetate anions in aqueous solutions at 298.15 K and the ionic strength I = 0.5 (KNO3) was studied. The thermodynamic parameters (logK, ΔrG, ΔrH, ΔrS) of these reactions were determined from calorimetric and pH-metric data. The most probable way of coordination of the amino acids in the heteroleptic complexes is discussed.

The complexation of lead(II) with a group of synthesized sorbents based on aminopolystyrene and substituted phenols having structurally different substituents of various electronic natures in the para position with respect to phenolic hydroxyl was studied. As third components, α-dinitrophenol and γ-dinitrophenol were examined. The following most important parameters of sorption were determined: the optimum pH value of quantitative sorption (pHopt), the recovery (R, %), the sorption capacity of the sorbent (SCSPb, mg/g), the half-sorption pH value (pH50), and the temperature and time (τ) of sorption in the presence of a third component. The structure of the mixed-ligand complex was determined.

The formation of the heteroleptic complexes FeEdtaIda3− and FeEdtaEn−(Ida2− is the iminodiacetate anion and En is ethylenediamine) was examined by direct calorimetry, pH potentiometry, and spectrophotometry at 298.15 K and the ionic strength I = 0.5 (KNO3). A possible way of coordination of the ligands in the heteroleptic complexes was discussed.

[Co(CN)2(H3Cdta)] · 2H2O (I) and Na2[Co(CN)(Cdta)] · 3H2O (II) (Cdta4− is the 1,2-cyclohexanediaminetetraacetate) were synthesized. In I, the two cyanide ions and the Cdta nitrogen atoms are located in the equatorial plane, the carboxyl groups connected to different N atoms are in axial positions; in addition one of them, like two other uncoordinated carboxyl groups, is protonated. In II, Cdta is a pentadentate ligand coordinated in the cis-equatorial mode. UV excitation of the dicyano complexes at the ligand-to-metal charge transfer band gives organic derivatives of cobalt(III) stable enough for chromatographic isolation. Photolysis of II in neutral medium gives aqua(cyclohexanediaminetriacetato)cobalt (III) complexes as the final products.

Mixed-ligand inner complexes of praseodymium(III) containing coordinated glycine or methionine ions and tartaric acid were synthesized. The compositions of the complexes were determined, and their spectral and thermal properties were studied. The coordination modes of the ligands were determined based on the results.

The adequacy of a stochastic model for choosing ligands which makes it possible to determine the regions of allowable values of the stability constants of complexes, the reduction of which occurs with the formation of an alloy, and choose ligands on the basis of these data is verified. Experimental data for alloy electrodeposition from solutions with complexes of different ligands and complexes of multivalent ions that are in published data show a good agreement with predictions by this model, which made it possible to formulate an important-for-practice condition of choosing ligands for joint reduction of complexes and the formation of an alloy.

New mixed-ligand coordination compounds[Cd(DMSO)5(NCS)][Cr(NH3)2(NCS)4] · 3DMSO (I) and [Mn(DMSO)4(H2O)2][Cr(NH3)2(NCS)4]2 · 6DMSO · 2H2O (II) have been synthesized and studied by IR spectroscopy and X-ray diffraction analysis. The crystals of compound I are monoclinic, a = 14.5275(7), b = 23.1692(11), c = 14.6969(6) A, β = 97.057(2)°, V = 4909.4(4) A3, space group P21/c, Z = 4, ρcalcd = 1.507 g/cm3, R = 0.0556. The crystals of compound II are triclinic, a = 11.7784(3), b = 12.1760(3), c = 13.1922(2) A, α = 85.5420(10)°, β = 87.9000(10)°, γ = 70.3680(10)°, V = 1776.46(7) A3, space group P $$ \overline 1 $$ , Z = 1, ρcalcd = 1.444 g/cm3, R = 0.0350.

The mixed ligand coordination compounds EuL(i-Bu2PS2)2(NO3) (L = Phen, 2,2′-Bipy, 4,4′-Bipy) are synthesized. On the basis of X-ray analysis and IR spectra their structures are elucidated. The complexes containing Phen or 2,2′-Bipy are found to possess photoluminescent property.

A method involving the use of paper ionophoresis is described for the study of the equilibria in mixed ligand complex systems in solution. Present method is based on the movement of a spot of metal ion under the electric field with the complexants added in the background electrolyte at pH 8.5. The concentration of primary ligand nitrilotriacetate (NTA) was kept constant while that of the secondary ligand methylcysteine was varied. The plot of log [methylcysteine] versus mobility were used to obtain information on the formation of mixed complexes and to calculate its stability constants. The binary equilibria metal(II)-methylcysteine and metal(II)-NTA have also been studied, since this is a prerequisite for the investigation of mixed complexes. The stability constants of the complexes Pb(II)-NTA-methylcysteine and UO2 (II)-NTA-methylcysteine were found to be 3.03 ± 0.05 and 3.42 ± 0.09 (log K values) at ionic strength 0.01 M and a temperature of 35°C.

The formation of the mixed-ligand complexes HgEdtaL2−, where L = 2,2′-dipyridine (Dipy) or 1,10-phenanthroline (Phen), was studied by calorimetry and pH titration at 298.15 K and the ionic strength I = 0.5 (NaClO4, KNO3). The heats of the formation of the dipyridine and phenanthroline complexes of mercury(II) determined at 298.15 K and the ionic strength I = 0.1 (NaNO3, KNO3). A probable coordination mode of the ligands in a mixed complex was discussed.

Mixed ligand complexes of dioxomolybdenum(VI) with 2-hydroxybenzaldehyde 4-phenyl-S-methylthiosemicarbazone (H2L) were prepared with the formula [MoO2(L)D] (D = H2O, methyl, n-butyl, and n-undecyl alcohol, DMF, DMSO, pyridine, 4-picoline, and 3,5-lutidine). The compounds were characterized by elemental analysis, IR and 1H NMR spectroscopy. The thermal decomposition of the compounds were investigated by using TGA, DTG, and DTA methods in air, and the thermal behavior depending on the second ligand molecule was discussed. A single crystal of the DMF coordinated complex was studied by X-ray diffractometry.

The crystal structure of mixed-ligand silver(I) hydrogen iminodiacetate has been studied. The composition of the [Ag2(C4H6NO4)(NO3)(H2O)]n ([Ag2(HIda)(NO3)(H2O)]n) coordination polymer has been refined. The NO3 and H2O ligands in the complex form rather weak coordination bonds with the Ag atoms. The system of hydrogen bonds in the structure has been considered. The formation of a chain of hydrogen bonds between the disordered H2O molecules was established.

The photochemical behavior of mixed-ligand complexes of europium carboxylates with nitrogen-and phosphorus-containing neutral ligands of island and dimer types, Eu(L)3 · xD · nH2O and [Eu(L)3 · xD]2 · nH2O (L is the trifluoroacetate, toluate, or cinnamate anion), was studied. During UV irradiation of the complexes of europium carboxylates with 1,10-phenanthroline and 2,2′-dipyridyl, a luminescence buildup was observed. EPR measurements demonstrated that the observed buildup of luminescence from europium occurs in parallel with the increase of the concentration of radical anions formed from neutral ligands.

The reaction of the copper(I) 2,9-dimethyl-1,10-phenanthroline (neocuproine, DMP) complex with 2,3,8,9-dibenzo-4,7-dimethyl-5,6-dihydro-1,10-phenanthroline (cuprotest, DMQ) in a CD3OD solution has been studied by 1H NMR spectroscopy. The substitution of DMQ for the DMP liqand in the inner coordination sphere of the Cu+ complex has been observed. A model of the process including the formation of a mixed-ligand complex, presumably of bridged structure, is proposed to describe the observed experimental dependences of integrated intensities of the NMR signals in the spectrum on the concentrations of the components of the solution.

The results of study of ethylene oligomerization in the presence of complex catalysts based on mixed-ligand β-diketonatozirconium chlorides are presented. The influence of the composition of a zirconium compound, the electron affinity of β-diketonate ligands, component ratio of the catalytic system, temperature of the process, solvent nature, and other factors on the catalyst activity and molecular-mass distribution of the product of ethylene oligomerization was studied.

The interaction of the copper(I) complex of 2,9-dimethyl-1,10-phenanthroline (neocuproine, DMP) with 2,3,8,9-dibenzo-4,7-dimethyl-5,6-dihydro-1,10-phenanthroline (cuprotest, DMQ) in a CD3OD solution has been studied by 1H NMR. DMQ is substituted for the DMP ligand in the inner coordination sphere of the Cu+ complex. To describe the experimental integrated intensities of NMR signals as a function of concentrations of the components, a model of the process is proposed implying the formation of a heteroleptic complex, which, presumably, has a bridging structure.

The thermodynamic parameters of reaction (logK, Δr G 0, Δr H, Δr S) are determined for the mixed-ligand complex formation of SmEdta− and CeEdta− with glycinate, iminodiacetate, aspartate, and nitrilotriacetate ions in aqueous solution at 298.15 K and ionic strength of I = 0.5 (KNO3). Based on these thermodynamic data, the most likely coordination modes are suggested for the complexone and the ancillary ligand in the mixed-ligand complexes.

The crystal structures of [Mn(Heida)(Phen)]2 · 7H2O (I) and [Mn2(Edta)(Phen)] · 4H2O (II) are studied by X-ray diffraction [R 1 = 0.0375 (0.0283) and wR 2 = 0.0954 (0.0662) for 5449 (3176) observed reflections in I (II), respectively]. Structure I contains mononuclear mixed-ligand complexes [Mn(Heida)(Phen)] and [Mn(Heida)(Phen)(H2O)]. In structure II, the [Mn(Edta)]2− anionic complexes and the [Mn(Phen)(H2O)2]2+ cationic complexes are linked by the bridging carboxyl groups into the tetramers with C 2 symmetry. In both compounds, two independent Mn atoms have different coordination numbers (6 and 7).

The luminescence and magnetic properties of mixed-ligand europium trifluoroacetates with nitrogen- and phosphorus-containing neutral ligands [Eu(TFA)3 · 3H2O]2 and Eu(TFA)3 · 2D · nH2O were studied (here TFA is the trifluoroacetic acid anion, and D is Phen (1,10-phenanthroline), n = 1; DMF (dimethylformamide), n = 1; or TPPO (triphenylphosphine oxide), n = 3). The molar magnetic susceptibility increased in the series of complex compounds Eu(TFA)3 · 2Phen · H2O < [Eu(TFA)3 · 3H2O]2 < Eu(TFA)3 · 2DMF · H2O < Eu(TFA)3 · 2TPPO · 3H2O. Correlations were found between the luminescent and magnetic characteristics of the complex compounds.

Proceeding with our research into Pd(II) and Au (III) complexes with 2-phenylpyridine [4, 5], in this work we synthesized mixed-ligand cyclometalated complexes based on the deprotonated form of 2benzylpyridine (benzpy) with 2,2'-bipyridyl (bpy) and 1,10-phenantroline (phen) (see scheme) and identified the products by Н NMR, electronic absorption and emission spectroscopy, and cyclic voltammetry. The electronic absorption spectra of these complexes, like the spectra of cyclometalated complexes based on 2-phenylpyridine [4, 5], characteristically show bathochromically shifted of intraligand bands and by the appearance of a new band in the region of 330–370 nm, assigned to a charge-transfer transition.

The thermodynamic parameters (logK, ΔrG0, ΔrH, ΔrS) of formation of the HgEdtaL2−, HgEdtaHL− and (HgEdta)2L4− complexes (L = NH2(CH2)2NH2, NH2(CH2)6NH2) have been determined by the calorimetric and pH-metric methods at 298.15 K and the ionic strength I = 0.5 (NaClO4). The most probable coordination mode for the complexone and an ancillary ligand in the composition of the mixed complexes was discussed.

pH titration shows that 1 : 1 : 1 mixed-ligand complexes are formed in the systems palladium(II)-Cyt-Glu-H2O (loggB = 19.73) and palladium(II)-Cyt-Lys-H2O (logβ = 16.20). Complexes Pd(C5H5N5)(C5H8NO4)Cl, Pd(C5H5N5)(C6H13N2O2)Cl, Pd(C4H5N3O)(C6H13N2O2)Cl, and Pd(C4H5N3O)(C5H8NO4)Cl are synthesized and characterized by chemical analysis, X-ray powder diffraction, and thermogravimetry. The coordination mode of amino acids, cytosine, and adenine to the palladium(II) ion is determined.

A method or the synthesis, isolation, and purification of a mixed-ligand complex of heparin with copper and glycine cations was suggested. The complex was studied by elemental, thermal, and spectral analyses. The elemental and crystalline hydrate compositions of the complex were determined and the molecular formula was suggested to be Na3CuHepGly · 2H2O.