Search

Coordination compounds of dysprosium(III) with diacyldihydrazones of saturated dicarboxylic acids, imino-, oxo-, and thiodiacetic acids, and 3-methyl-1-phenyl-4-formylpyrazol-5-one (H4L) are described. [Dy2(H2LO)3] · 7.5CH3OH · 3H2O was subjected to X-ray diffraction analysis: space group \(R\bar 3\), a = 17.349(1) A, c = 65.669(4) A, Z = 6, R = 0.076, Rw = 0.243 (5301 reflections with I ≥ 2σ(I)). The complex is established to have a binuclear structure and contain dysprosium ions linked via three bridging ligands. The coordination polyhedron of the Dy atom had a three-capped trigonal prism geometry. The magnetic properties of the synthesized complexes were studied.

850 Within the framework of collaboration between institutes of physics of the atmosphere in Russia (Obukhov Institute of Physics of the Atmosphere, Russian Academy of Sciences, IPA RAS) and China (Institute of Atmospheric Physics, Chinese Academy of Sciences, IAP CAS), studies on ecological–cli matic problems regarding the capital regions of both countries are actively being pursued. The results of research in this field have been presented, for example, in the collection of abstracts of the Russian–Chinese conference [1].

A series of isostructural complexes of the formula Ln(acac)3L (where Hacac is the acetylacetone, L is the 5-phenyl-2-(2-pyridyl)-7,8-benzo-6,5-dihydro-1,3,6-triazaindolizine, Ln are the LaIII, TbIII, EuIII, and SmIII) was studied. Molecular and crystal structures of terbium and samarium complexes were established by X-ray diffraction analysis. Luminescence properties of solid samples were studied. Coordination of 5-phenyl-2-(2-pyridyl)-7,8-benzo-6,5-dihydro-1,3,6-triazaindolizine as an additional ligand increases intensity of photoluminescence. Luminescence spectra of compositions Eu x Tb1−x (acac)3L and La0.6Eu0.1Tb0.3(acac)3L were studied. A combination of several lanthanide ions allowed us to obtain almost white emission.

Copper(II) coordination compounds with 3-(pyridin-2-yl)-5-(2-salicylideniminophenyl)-1H-1,2,4-triazole and 1,3-bis(5-(pyridin-2-yl)-1,2,4-triazole-3-yl)propane have been synthesized. The complexes have been studied by elemental and thermal analysis, IR and electron spectroscopy, electron paramagnetic resonance (EPR), and magnetochemistry. According to X-ray diffraction data, the complexes have binuclear structures in which metal cations are bonded via the nitrogen atoms of two bridging triazole rings.

The reaction of ethanol solutions of benzoylhydrazones of 2-trifluoroacetylcycloalkanones (H2L) with a solution of nickel(II) acetate in aqueous ammonia in 1 : 1 ratio gave complexes NiL · NH3 with square structure. The composition and structure of the complexes were determined by elemental analysis, IR and 1H NMR spectroscopy, and X-ray diffraction analysis.

1-Alkyl-2-(2-tosylaminophenyl)-5-aminobenzimidazole and related zinc complexes are synthesized. The structure of the complex with zinc pivalate is determined by X-ray diffraction analysis. The fluorescence with the anomalous Stokes shift of the benzimidazole ligand system in solution is transformed into the fluorescence with the normal Stokes shift upon complex formation due to blocking the mechanism of intramolecular proton transfer in the excited state or upon the transition to the crystalline state formed by zwitterionic forms that are generated due to the proton transfer from the sulfonamide group to the amino group.

The reactions of transition metal trimethylacetates [Cu2(Piv)4(HPiv)2], [Ni9(OH)6(Piv)12(HPiv)4], [Co(Piv)2] n (Piv− = −O2CBut) with 1,1-cyclohexanediacetic acid (H2Chda) neutralized by tetrabutylammonium hydroxide in the presence of 2,2-bipyridine (2,2′-bpy) afford linear trinuclear homometallic complexes [(2,2′-bpy)2Cu3(Chda)2(Piv)2]··2EtOH (1) and [(2,2′-bpy)2M3(Chda)2(Piv)2(EtOH)2] (M = NiII (2) or CoII (3)). In molecules of these compounds, anions of both mono- and dicarboxylic acids act as bridges between the transition metal atoms. Compounds 1–3 were characterized by X-ray diffraction, and their magnetic properties were studied. Spin-spin ferromagnetic interactions dominate in complexes 1–3 with CuII (S = 1/2) (1) and CoII (S = 3/2) (3) ions.

Coordination compounds of neodymium(III) with acylhydrazones of saturated dicarboxylic acids and 3-methyl-1-phenyl-4-formylpyrazol-5-one are synthesized and studied. The structure of complex [Nd2(H2L2)3] · Me2SO · CH3OH · 6H2O is determined from the X-ray diffraction data for the isostructural lanthanum complex. The complex is binuclear and contains nine-vertex coordination polyhedra bound by three hydrocarbon spacers. Solid samples of the studied neodymium complexes exhibit luminescence in the near-infrared spectral range (λ = 874, 904, and 1059 nm) characteristic of this ion.

Radical cation salts of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) with the 8,8′-dichloro derivative of cobalt bis(1,2-dicarbollide) (BEDT-TTF)2[8,8′-Cl2-3,3′-Co(1,2-C2B9H10)2] (1) and (BMDT-TTF)4[8,8′-Cl2-3,3′-Co(1,2-C2B9H10)2] (2) were synthesized and their crystal structures and electrocon-ducting properties were determined. The synthesized radical cation salts are semiconductors with the conductivity σ293 = 1.5 and 2.0 Ohm−1 cm−1, respectively. A decrease in the size of the substituent in a series of (BEDT-TTF)2[8,8′-X2-3,3′-Co(1,2-C2B9H10)2] and (BMDT-TTF)4[8,8′-X2-3,3′-Co(1,2-C2B9H10)2] (X = I, Br, Cl) results in the compression of the anion sublattice of the crystal and compaction of the radical cation packing of the conducting layer, which, in turn, increases the conductivity of the crystals.

Coordination compounds of samarium with acyldihydrazones of saturated dicarboxylic acids and 3-methyl-1-phenyl-4-formylpyrazol-5-one have been synthesized and studied. According to X-ray diffraction, the complexes are binuclear and contain nine-vertex coordination polyhedra linked by three hydrocarbon spacers. Solid samples manifest intense luminescence in the spectral region typical for samarium(III) complexes.

The coordination compounds of neodymium(III), samarium(III), and europium(III) with the acyldihydrazones of imino-, oxo-, and thiodiacetic acids and 3-methyl-1-phenyl-4-formylpyrazol-5-one were synthesized and studied. According to X-ray diffraction data, the complexes are binuclear and the lanthanide cations are linked by three binucleating ligands. The coordination polyhedra have a three-cap triangular prism geometry, the prism bases being formed by oxygen atoms and the vertices being occupied by the imine nitrogen atoms. Solid Nd(III) and Sm(III) complexes show intense luminescence in the spectral regions characteristic of these cations. Europium(III) complexes are liminescence-inactive due to the low efficiency of excitation energy transfer to the resonance levels of the central atom.

New binuclear pivalate complexes (bath)2Tb2(piv)6 and (bath)2Tb2(piv)6·H2O (piv = = ButCCO2 −, bath is 4,7-diphenyl-1,10-phenanthroline) were synthesized. The thermal behavior of these complexes was studied by differential scanning calorimetry and thermogravimetric analysis. The composition of the complexes in the gas phase was determined, and their magnetic and photoluminescence properties were studied. The structures of the compounds (bath)2Tb2(piv)6 and (bath)2Tb2(piv)6·H2O were determined by X-ray diffraction.

Binuclear copper(II) complexes with bis(imidazolinyl)hydrazone of 2,6-diformyl-4-tert-butylphenol have been prepared and studied. In all complexes the antiferromagnetic exchange interaction between the copper(II) ions is observed.

4-Formyl-3-methyl-1-phenylpyrazol-5-one quinolin-2-yl-(H2L1) and benzothiazol-2-ylhydrazones (H2L2) were synthesized and studied. Quantum-chemical modeling of possible tautomers of the hydrazones was performed. Copper(II) complexes of the general formula [Cu(HL)(ROH)]Y (R = CH3, C2H5; Y=NO3, ClO4) were obtained and examined by IR and EPR spectroscopy, magnetochemistry, and X-ray diffraction. Additional coordination through the N atom of the pyrazole ring enables the complex molecules to form zigzag polymer chains linked by intermolecular hydrogen bonds.

A new Schiff’s base and its salt have been prepared from 2-aminophenyl(triphenyl)phosphonium chloride and 5-hydroxy-3-methyl-1-phenyl-4-formylpyrazole. The products structures have been proved by IR, 1H NMR, and UV spectroscopy, mass spectrometry, X-ray diffraction analysis, and quantum-chemical modeling. Possible tautomerism and some properties of the products have been studied.

The binuclear copper(II) complex with 2,6-diformyl-4-tert-butylphenol bis(imidazolinylhydrazone) (H3L), [Cu2(H2L)Br2]ClO4 (I), was synthesized. The structure of complex I was determined by X-ray diffraction analysis. The antiferromagnetic exchange interaction (2J = −108 cm−1) translated through the phenoxide oxygen atom is observed between the copper(II) ions. The exchange parameter was calculated by the quantum-chemical “broken symmetry” method.

The chemical reactivity of mixed-valence “platinum blue” of the composition [Pt(Bipy)(NHCOCH3)2NO3 · mH2O] n (I) towards water, concentrated HCl, and ethanol was studied. The reaction of compound I with water gave previously unknown binuclear Pt(III) acetamide [Pt2(Bipy)2(μ-NHCOCH3)2(NHCOCH3)2](NO3)2 · H2O (II) (yield 19%), which was studied by X-ray diffraction. Upon the reaction of “blue” I with HClconc, destruction took place to give PtBipyCl3 and Pt(IV) oxonium hexachloroplatinate (H3O)2[PtCl6] the structure of which was studied by X-ray diffraction; treatment of I with ethanol leads to partial reduction of the “blue” and destruction giving (according to X-ray diffraction data) the Pt(II) complex [Pt(Bipy)2](NO3)2 · H2O (III). Thermal decomposition of I under inert atmosphere was studied by DSC and TGA.

The coordination compounds Na[LnL4] · 2H2O and [NBu4][LnL4] (Ln = Nd, Sm, Eu, Tb; HL is 3-methyl-4-formyl-1-phenyl-5-pyrazolone) have been synthesized and studied by IR spectroscopy and thermogravimetry. According to X-ray diffraction data, the coordination polyhedra of lanthanides are shaped as square antiprisms and formed by the oxygen atoms of four deprotonated moieties of the enol form of 4-formyl-5-pyrazolone. In the complex Na[EuL4] · 2H2O, sodium cations are bonded to the two nitrogen atoms of pyrazole heterocycles, combining discrete complex anions into two interpenetrating three-dimensional frameworks. Polycrystalline samples of neodymium(III), samarium(III), and terbium(III) complexes manifest intense luminescence in the spectral regions that are typical for them.

Heteroligand coordination compounds Ln(Dbm)2HL · nEtOH, where Ln is Nd(III), Yb(III), and Er(III); HDbm is dibenzoylmethane; H2L is bis(5-pyridin-2-yl-1,2,4-triazol-3-yl)methane, are synthesized and studied. The complexes are studied by elemental analysis, TGA, and IR spectroscopy. The structure of complex [Nd(Dbm)2 · HL · EtOH] · EtOH is determined by X-ray diffraction analysis. The crystals are triclinic, space group \(P\bar 1\), a = 10.2004(9), b = 11.3809(10), c = 20.9173(18) A, α = 102.133(1)°, β = 103.568(1)°, γ = 100.306(2)°; Z = 2 (8416 reflections with I > 2σ(I), R = 0.053, Rw = 0.136). The luminescence of solid samples of the studied complexes is studied in the near-IR region.

Phthalazinylhydrazone of 2-formylpyrrole is synthesized, the values of ionization constants are determined, and quantum chemical calculation of the geometry and total energy of possible tautomers is performed. The structure of the cyclic oxidation product of hydrazone 3-(1H-pyrrolyl-2)-[1,2,4]-triazolo(3,4-a)phthalazine existing in the crystal in the form of dimers linked by two hydrogen bonds is described.

The reaction of an aqueous solution of vanadyl sulfate VOSO4·3H2O, butylmalonic acid (H2Bumal = C4H10(COOH)2), and lithium carbonate at pH ∼4–5 gave crystals of the complex Li4(VO)2(Bumal)4(H2O)8]·H2O (1). The structure of complex 1 was established by X-ray diffraction analysis. The molecule of complex 1 consists of two mononuclear bischelate dianionic units {VO(Bumal)2(H2O)} linked by four lithium ions to form the hexanuclear heterometallic {V2Li4} structure. The crystals and an ethanolic solution of compound 1 were studied by ESR spectroscopy.

New heterodinuclear pivalates (HPiv)6EuTb(Piv)6 (5) and (Phen)2EuTb(Piv)6 (6), where Piv = (CH3)3CCO2−, the 2,2-dimethylpropanoate anion, and Phen = 1,10-phenanthroline, were synthesized. The structures and compositions of the heterodinuclear molecules were determined by X-ray diffraction and based on magnetic measurements, inductively coupled plasma atomic emission spectrometry (ICP-AES) and the results of the research on the thermal decomposition and vaporization of the complexes. Under UV excitation, complex 6 exhibits luminescence and complete intramolecular excitation energy transfer to the Eu3+ ions involving singlet levels of the Phen ligand and f–f levels of the Tb3+ ions.

Novel heteroligand europium(III) and samarium(III) complexes with dibenzoylmethane (HDBM) and 5-phenyl-2-(2′-pyridyl)-7,8-benzo-6,5-dihydro-1,3,6-triazaindolizine (L), Ln(DBM)3L (Ln = Eu, Sm), were synthesized. The structure of the europium complex was determined by X-ray diffraction. It was shown that the use of L as an auxiliary ligand increases the luminescence intensity of lanthanides severalfold as compared with analogous complexes containing phenanthroline as the second ligand.

A reaction of (HPiv)2Cu2(Piv)4 with dimethylmalonic acid dipotassium salt (K2Me2mal) leads to the formation of a cage coordination polymer {(μ-H2O)6K8[(μ-H2O)Cu-(μ3,κ2-Me2mal)(μ6,κ2-Me2mal)]2[Cu2(μ5,κ2-Me2mal)2(μ5,κ2-Me2mal)2]}n (1). It was found that when 1 reacted with CdSO4·8H2O in a mixture of EtOH-H2O (3: 1), the potassium ions in 1 were displaced with cadmium(ii) ions with the formation of a heterometallic 1D-polymer [(κ1-H2O)4CdCu(μ,κ2-Me2mal)2]n (2). Compounds 1 and 2 were characterized by X-ray crystallography and ESR spectroscopy.

A reaction of vanadyl sulfate VOSO4·3H2O with dimethylmalonic acid strontium salt led to the coordination polymer {Sr(H2O)8[VO(Me2mal)2]} n (1, Me2mal is the dimethylmalonic acid dianion), in which the carboxylate dianions did not form chelate metallocycles with the vanadyl ions. The complex was studied by ESR spectroscopy. The compound 1 exhibited weak spin-spin exchange interactions of ferromagnetic type between the VIV atoms.

New dinuclear lanthanide pivalate complexes [Tb2(piv)6(Hpiv)6], [Tb2(piv)6(bpy)2], [Tb2(piv)6(phen)2], [Tb2(piv)6(bath)2]·1.5EtOH, and [Eu2(piv)6(bath)2]·2EtOH, as well as the coordination polymer {Tb(piv)3}n, in which piv = (CH3)3CCO2–, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, bath = 4,7-diphenyl-1,10-phenanthroline, and EtOH = ethanol, were synthesized and characterized by X-ray diffraction. For the terbium complexes, the magnetic properties and the solid-state thermolysis were investigated. The phase composition of the solid decomposition products was determined by X-ray powder diffraction. The photophysical properties of these complexes were analyzed by luminescence, excitation, and phosphorescence spectroscopy, and by lifetime measurements. A comparison of the photophysical data for bpy, phen, and bath complexes shows that the supramolecular organization affects the efficiency of the sensitization of Ln3+ luminescence. All the results obtained provide good prospects for the use of dinuclear lanthanide pivalate complexes as efficient light-conversion molecular devices (LCMD).

The reactions of partially hydrogenated indole-fused quinolizines and indolizines with activated alkynes in methanol, acetonitrile, and dichloromethane were studied. The reactions were shown to be accompanied by the cleavage of the bridging C-N bond. Azecino[5,4-b]-indole and indolo[3,2-e][2]benzazonine derivatives were synthesized.

The reactions of oxovanadium(iv) salts with dimethylmalonate anions (H2Dmm — C3H6(COOH)2) and chelating N-donor ligands (2,2′:6′,2″-terpyridine (terpy), 2,2′-bipyridine (bpy)) led to the formation of new mononuclear heterochelate complexes [VO(Dmm)(terpy)]·4H2O (1) and [VO(Dmm)(bpy)(H2O)] (2). The structures of the synthesized compounds were determined by X-ray diffraction. The ESR spectra of the compounds at 293 and 100 K were analyzed and simulated. The photoluminescence properties were investigated.

Mono- and bistriazoles ligands have been used to prepare ternary mixed ligand europium(III) complexes in which the remaining ligands are dibenzoylmethane anions (DBM). The complexes were characterized by various measurements including single-crystal X-ray crystallography. Photophysical studies on both ligands and the complexes were carried out. The complexes show strong sharp red emissions in the solid state corresponding to 5 D 0 → 7 F J ( J = 0–3) with a 5 D 0 → 7 F 2 (612–613 nm) transition as the most prominent one. It was shown that high thermal stability, luminescence intensity and quantum yield comparable or higher than those for the Eu(DBM) 3 Phen makes such complexes a promising material for OLED.

The interaction of cymantrenylcarboxylic acid (C5H4CO2H)Mn(CO)3 (CymCOOH) or its potassium salts with salts of Cu (II) in alcohol or water with subsequent treatment with ligands L gives binuclear complexes LCu(CymCOO)4CuL where L = THF (I), Et2O (II), CymCOOH (III) or PPh3 (IV). The structures of I–III were solved by X-ray analyses. The frame of all complexes is constructed as “paddle-wheel” with four carboxylate bridges. At thermal decomposition of I and II in Ar the loss of L ligands took place, then the decarboxylation of all CymCOO groups was observed followed by decarbonylation with elimination of nine CO groups only. Finally the loss of cyclopentadienyl ligands results the solid product which according to powder XRD data contains metallic copper and Mn1.5Cu1.5O4 phase probably due to the splitting of the retaining CO groups.

Platinum blues with the composition Pt(phen)(NHCOMe)2X (phen is 1,10-phenanthroline, X = NO3 −, CF3SO3 −, or Cl−), were synthesized starting from the complex [Pt2(NHCOMe)4Cl2]. The resulting compounds apparently have a polymeric structure with metal centers in different valence states. The reaction of the complex Pt(phen)(NHCOMe)2NO3 with H2O affords crystalline binuclear acetamidate [PtIII 2(phen)2(μ-NHCOMe)2(NHCOMe)2](NO3)2, whose structure was determined by X-ray diffraction. The reaction of the complex Pt(phen)(NHCOMe)2NO3 with HCF3SO3 leads to the decomposition of the starting compound, the reduction of the Pt atoms, and the formation of the complex [PtII 2(phen)4](CF3SO3)4. The thermal decomposition of the resulting complexes, as well as the complexes [(phen)Pt-(μ-NHCOMe)2Pt(phen)]2(NO3)4 and [Pt(phen)Cl2], under an inert atmosphere was studied by DSC and TGA. Metallic platinum nanopowders are thermal decomposition products of the complexes under study.

2,6-Bis(5-trifluoromethylpyrazol-3-yl)pyridine (H2L) and its mono-, tri-, and tetranuclear NiII complexes were synthesized for the first time. All the obtained compounds were characterized by single-crystal X-ray diffraction analysis. In the complexes, 2,6-bis(5-trifluoromethylpyrazol-3-yl)pyridine exists in the neutral and dianionic forms and exhibits different coordination modes (κ3-, μ2-κ3:κ1-, and μ3-κ3:κ1:κ1). The electrochemical and magnetic properties of all compounds were studied. The tetranuclear NiII complex with the L2− dianion is reduced in two sequential reversible one-electron steps.

The reaction of nickel pivalate Ni9(OH)6(Piv)12(HPiv)4 (Piv is anion of pivalic acid) and triethylenetetraamine (L1) (Ni : L1 = 1 : 1) in MeCN with following addition of isophthalaldehyde (L2, L1 : L2 = 1 : 1) results in the formation of Ni2L(Piv)4 (I), containing new macrocyclic ligand L3 formed as a result of [2+2] condensation of L1 with L2. The new compound was characterized by single crystal X-ray diffraction and magnetic measurements.

Trinuclear heterometallic complexes containing the {M2Ln(Piv)6(NO3)} (MII = Ni, Cu; LnIII = Nd, Pr, Sm, Eu, Gd; Piv− is the anion of pivalic acid) and {Cu2Ln(Piv)8)]− (LnIII = Eu, Gd) metal cores were synthesized, their structures and magnetic properties were studied. For the most compounds, it was shown that their magnetic properties can be interpreted taking no interaction of the 3d-metal ions and a lanthanide into account. Ferromagnetic exchange interactions were found to exist between the unpaired electrons of the paramagnetic centers in the exchange clusters of the gadolinium-containing heterometallic complexes {M-Gd-M} (M = Ni or Cu).

A copper(II) complex with salicylaldehyde N-(2-salicylideneiminoglutaryl)hydrazone (H4L) of the formula [Cu2L · 2Py]2 · 8H2O (I) was obtained and characterized by X-ray diffraction. The crystals are monoclinic, space group P21, a = 13.0663 A, b = 16.5553 A, c = 17.7650 A, β = 97.9420°; Z = 4. The complex is tetranuclear with a “dimer-of-dimers” structure in which the copper cations of two binuclear subunits are linked by phenoxy bridges. The EPR spectra of solutions of complex I show a superposition of two signals of four HFS lines (g1 = 2.111, a1 = 56.8 × 10−4 cm−1 and g2 = 2.183, a2 = 71.0 × 10−4 cm−1).

Binuclear heterometallic complexes (η2-bpy)CoLn(Piv)5(H2O), (η2-bpy)NiLn(Piv)5(H2O), and (η2-bpy)CuLn(Piv)5(HPiv) (Ln = Sm or Gd, Piv- is the pivalate anion) were synthesized. A comparative study of the structural characteristics and the thermolysis of the resulting compounds was performed.

The reaction of 3-(pyridin-2-yl)-5-(2-aminophenyl)-1H-1,2,4-triazole and salicylaldehyde or benzaldehyde leads a new type of 1,2,4-triazole’s derivats. Reactions of these ligands with zinc acetate in ethanol lead to the formation of two new complexes with azomethine or dihydrotriazaindolizine form of ligands. The structures of these complexes were investigated by X-ray analysis. The complexes showed strong green–blue luminescence in solid state.

2,3-Dihydrofuro[3,2-c]coumarin-3-one was synthesized in quantitative yield from 3-(ω-bromoacetyl)-4-hydroxycoumarin in the presence of nucleophiles (including solvents). This compound undergoes keto-enol tautomerization and easily reacts with aromatic and heteroaromatic aldehydes to form crotonization products having a Z configuration and exhibiting strong fluorescence.

A reaction of the dimer [Mn(CO)4(SPh)]2 with (PPh3)2Pt(C2Ph2) gave the heterometallic complex (CO)4Mn(μ-SPh)Pt(PPh3)2 (I) and its isomer (CO)3(PPh3)Mn(μ-SPh)Pt(PPh3)(CO) (II). A reaction of complex I with a diphosphine ligand (Dppm) yielded the heterometallic complex (CO)3Mn(μ-SPh)Pt(PPh3)(Dppm) (III). Complexes I–III were characterized by X-ray diffraction. In complex I, the single Mn-Pt bond (2.6946(3) A) is supplemented with a thiolate bridge with the shortened Pt-S and Mn-S bonds (2.3129(5) and 2.2900(6) A, respectively). Unlike complex I, in complex II, one phosphine group at the Pt atom is exchanged for one CO group at the Mn atom. The Mn-Pt bond (2.633(1) A) and the thiolate bridge (Pt-S, 2.332(2) A; Mn-S, 2.291(2) A) are retained. In complex III, the Mn-Pt bond (2.623(1) A) is supplemented with thiolate (Pt-S, 2.341(2) A; Mn-S, 2.292(2) 0A) and Dppm bridges (Pt-P, 2.240(1)A; Mn-P, 2.245(2) A). Apparently, the Pt atom in complexes I–III is attached to the formally double bond , as in Pt complexes with olefins.

2-(N-Tosylamino)benzaldehyde 1-phthalazinylhydrazone (H2L) and its complexes with Cu(II), Ni(II), and Mn(II) were obtained. The acid-basic properties of the hydrazone were studied using potentiometry and spectrophotometry. The experimental data were compared with the results of quantum-chemical DFT calculations. The structure of the binuclear complex [Cu2L2] was determined using X-ray diffraction. The broken symmetry approach was used to calculate the exchange coupling constant of the copper ions.

A reaction of [(η5-C6H7)Fe(CO)3]BF4 with KI in acetone gave brown crystals of the complex [(η5-C6H7)Fe(CO)2]I (I), which was treated with SnCl2 in THF to form orange crystals of the complex [(η5-C6H7)Fe(CO)2]SnCl3 (II). A reaction of complex II with potassium cymantrenecarboxylate ((CO)3MnC5H4COOK, or CymCOOK) in THF yielded yellow crystals of the complex [(η5-C6H7)Fe(CO)2]Sn(CymCOO)3 (III). Structures I–III were identified using X-ray diffraction. The fragment (η5-C6H7)Fe(CO)2 in complexes I–III remains virtually unchanged. The Fe-I bonds in complex I (2.6407(3) A) and the Fe-Sn bonds in complexes II and III (2.4854(3) and 2.4787(4) A, respectively) are appreciably shorter than the sum of the covalent radii of the corresponding elements, probably because of an additional dative interaction of the d electrons of iron with the vacant d orbitals of iodine or tin.

Reactions of acetamide with platinum(II) diamines [Pt(N,N-DimeEn)Cl2], [Pt(Tm)Cl2], and [Pt(N,N-DimeTm)Cl2] (N,N-DimeEn = (CH3)2N(CH2)2NH2, Tm = NH2(CH2)3NH2, N,N-DimeTm = (CH3)2N(CH2)3NH2) with preliminary precipitation of chlorine ions by silver salts gave binuclear Pt(II) acetamidates [Pt2(CH3)2N(CH2)2NH2)2(μ-NHCOCH3)2](NO3)2 · H2O (I), [Pt2(NH2(CH2)3NH2)2)(μ-NHCOCH3)2](NO3)2 · H2O (II), and [Pt2(CH3)2N(CH2)3NH2)2(μ-NHCOCH3)2](HSO4)2 (III), whose crystal structures were determined. Crystals of I are monoclinic: a = 14.459(2) A, b = 17.197(3) A, c = 9.822(2) A, β = 105.923(10)°, V = 3348.6(8) A3, space group P2(1)/c, Z = 4, Rhkl = 0.0419 for 6663 reflections. Complex I is a binuclear acetamidate with bridging (NHCOCH3)− ligands, one of which is bound to two Pt atoms through the N and O atoms, and the other ligand is bound only through the N atom. The Pt-Pt distance is 2.987(1) A. Crystals of II are monoclinic: a = 10.213(7) A, b = 13.373(9) A, c = 16.533(11) A, β = 97.971(9)°, V = 2236(3) A3, space group P2(1)/n, Z = 4, Rhkl = 0.557 for 6462 reflections. The Pt-Pt distance is 3.057(1) A. Crystals of III are monoclinic: a = 10.557(12) A, b = 18.531(2) A, c = 14.4744(17) A, β = 108.705(2)°, V = 2682(5) A3, space group P2(1)/n, Z = 4, Rhkl = 0.569 for 8506 reflections. The Pt-Pt distance is 3.202(1) A. Complexes II and III are binuclear acetamidates, in which two chelating Pt(Tm) or Pt(N,N-DimeTm) moieties are coordinated through the N and O atoms of (NHCOCH3)−cis-bridges.

A series of novel complexes NiLn · NH3 were obtained by reactions of equimolar amounts of the ligands H2Ln (prepared by condensation of aroyl(perfluoroacyl)methanes with benzoylhydrazine) as solutions in ethanol and nickel(II) acetate as a solution in aqueous ammonia. The empirical formulas and square planar structures of the complexes obtained were determined using elemental analysis, IR and 1H NMR spectroscopy, and X-ray diffraction.

The undecanuclear complex [Ni11(OH)2(mhp)8(Piv)10(HCO2)2(H2O)2(Hmhp)2(HPiv)2] (2, where Piv is the anion of pivalic acid) containing 6-methyl-2-pyridonate, pivalate and formate anions have been obtained as a result of interaction of trimethylacetate (or pivalate) nickel(II) complex [Ni9(OH)6(Piv)12(HPiv)4] with 2-hydroxy-6-methylpyridine in dimethoxyethane, containing about 0.50% of methyl formate. The structure of 2 is determined using X-ray diffraction analysis and its magnetic susceptibility is measured between 2 and 300 K. It is shown that complicated low-temperature magnetic behavior of 2 is due to combined influence of competing ferro- and antiferromagnetic interactions, zero-field splitting effect and anisotropic exchange interactions in the Ni11 clusters.

New coordination compounds of zinc with 3-(pyridine-2-yl)-5-(2-salicylideneiminophenyl)-1H-1,2,4-triazole (H2L1) and 3-(pyridine-4-yl)-5-(2-salicylideneiminophenyl)-1H-1,2,4-triazole (H2L2) are obtained. According to X-ray diffraction data, binuclear zinc complexes with L1, namely, [Zn2L 2 1 ]. 0.5EtOH and [Zn2L 2 1 ] · 2C4H8O2 · 2H2O obtained in different solvents, are structurally related molecular complexes. The product of the reaction with H2L2 is the {[ZnL2(Py)] · CHCl3} n coordination polymer. The 1,2,4-triazoles under study and the complexes on their basis luminesce in solutions with emission maxima ranging from 412 to 503 nm. These coordination compounds in the solid state emit in the green range of the spectrum (λmax = 496 and 485 nm).

Mechanisms of intramolecular transformations of carbanions generated from 2-aza-1,3,5-trienes by the action of potassium tert-butoxide, which could lead to homo- or heteroannular azacycloheptadienes, were studied by quantum-chemical methods in terms of the density functional theory. The corresponding gradient channels were localized for model 1-methylsulfanyl-1-(cyclopentylideneamino)- and 1-methylsulfanyl-1-(cyclohexylideneamino)buta-1,3-dien-2-ols. Analysis of the kinetic and thermodynamic parameters showed that carbanion generated from N-cyclopentylidenebuta-1,3-dien-1-amine undergoes rearrangement mainly into homoannular azacycloheptadiene and that analogous N-cyclohexylidene derivative gives rise to heteroannular isomer. The results of calculations were consistent with the experimental data.

Uranyl complexes with ethylmethylglyoxime were studied. The structure of (CN3H6)4[(UO2)2(CO3)(C2O4)2(C5H8N2O2)] · 1.5H2O was determined by X-ray crystallography. The structure of the complex is binuclear with a double carbonate dioximate bridging fragment.

Treatment of platinum(II) diamine [Pt(N,N-DimeTm)Cl2] (I) with pyridine gave tetramine [Pt(N,N-DimeTm)Py2]Cl2 (II); by oxidation with chlorine this was converted to Pt(IV) triamine, [Pt“(N,N-DimeTm(Py)Cl3]Cl (III) with a six-membered chelate ring. According to X-ray diffraction data, the reaction of complex II with chlorine is accompanied by removal of the pyridine molecule from the trans-position to the NH2 group of N,N-dimethyltrimethylenediamine. The reaction of complex III with chlorine at 20°C afforded a mixture of compounds (IV) and the complex [Pt“(CH3)2N(CH2)2C(O)NH”(Py)Cl3] (V) with an amidate six-membered metal ring, dimethylpropioamide, which was also isolated upon refluxing a mixture of IV in an aqueous solution. The UV/Vis and IR spectra of the obtained complexes were studied, and X-ray diffraction analysis of I, III, and V was performed. The crystals of I are triclinic, space group P\( \bar 1 \); a = 7.6526(4) A, b = 11.5571(6) A, c = 12.4432(7) A, α = 113.85(1)°, β = 96.54(2)°, γ = 106.78(2)°; Z = 4; Rhkl = 0.051. The crystals of III are monoclinic, space group C2/c; a = 36.715(2) A, b = 7.8179(4) A, c = 29.721(16) A, β = 127.80(1)°; Z = 16; Rhkl = 0.036. The crystals of V are monoclinic, space group P21/n; a = 7.0398(6) A, b = 27.458(2) A, c = 7.687(6) A, β = 106.270(1)°; Z = 4; Rhkl = 0.052.

The thermal stability and the solid-state thermal decomposition of the known mononuclear cobalt(II) and nickel(II) complexes [H2N(C5H3N)N(H)C(Me)=NH]M(OOCBut)2, [(NH2)2C6H2Me2]3M(OOCBut)2 and the new compounds L2M(OOCBut)2 (L = = (2-NH2)C5H3N, (2-NH2)(6-Me)C5H3N), and [(2,6-NH2)2C5H3N]2Ni(OOCBut)2 were studied by differential scanning calorimetry and thermogravimetric analysis. Efficient methods were developed for the synthesis of these complexes. The mononuclear complexes are thermally quite stable. The thermal stability of the complexes depends on the nature of the ligand and decreases in the series (2,6-NH2)2C5H3N > H2N(C5H3N)NHC(Me)=NH > (NH2)2C6H2Me2 > (2-NH2)C5H3N > (2-NH2)(6-Me)C5H3N. The nickel(II) complexes are thermally more stable than the related cobalt(II) complexes. The thermolysis (

The radical cation salts of tetrathiafulvalene (TTF) and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) with iodo derivatives of cobalt bis(dicarbollide), (TTF)[9,9′,12,12′-I4-3,3′-Co(1,2-C2B9H9)2] and (BEDT-TTF)[9,9′(12′)-I2-3,3′-Co(1,2-C2B9H10)2], respectively, were synthesized and their crystal structures were determined. The introduction of iodine atoms into the lower rim of the dicarbollide ligands, unlike the substitution at the upper rim, leads to insignificant changes in the crystal structure and the conductivity of the radical cation salts compared to the analogous salts based on unsubstituted cobalt bis(dicarbollide).