Russian Journal of Coordination Chemistry最新文献

The La(III) bis(amidinate) amido complex {2-[Ph₂Р(O)]C₆H₄NC(Bu^t)N(2,6-Me₂C₆H₃)}₂LaN(SiMe₃)₂ (I) was synthesized by the reaction of 2-[Ph₂Р(O)]C₆H₄NHC(Bu^t)=N(2,6-Me₂C₆H₃) (HL) and La[N(SiMe₃)₂]₃ in 2 : 1 molar ratio and isolated in 74% yield. X-ray analysis revealed that in I both monoanionic amidinate ligands are κ³-N,N,O-coordinated to La(III) ion. Complex I demonstrates high catalytic activity in ring-opening polymerization of cyclic esters and enables 100% conversion of 100–300 equiv of rac-lactide in 30 min or 100–500 equiv of ε-caprolactone in 1 min providing highly controlled polymerization. The obtained polymeric samples feature linear dependence of molecular weight vs. the monomer loading and rather narrow polydispersity (M_w/M_n = 1.36–1.88).

The new ferrocenyl-containing β-diketonate complexes with crown-ethers [Ca(Fctfa)₂(15-crown-5)] (I), [Sr(Fctfa)₂(18-crown-6)] (II), [Sr(Fctfa)₂(18-crown-6)](CH₂Cl₂) (III), [Ba(Fctfa)₂(18-crown-6)] (IV) and [Ba(Fctfa)₂(18-crown-6)](CH₂Cl₂) (V) (Fctfa = 1-ferrocenyl-4,4,4-trifluorobutane-1,3-dionato), 15-crown-5 = 1,4,7,10,13-pentanoxacyclopentadecane; 18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane) have been synthesized. The compounds are characterized by infrared and ¹H NMR spectroscopy and X-ray diffraction analysis. The thermal behavior of complexes I, II, IV was investigated by thermal analysis. It was found that complexes are thermally stable up to 150°C for I, 215°C for II 180°C for IV. The decomposition behavior of I, II, IV studied by ¹H nuclear magnetic resonance investigation of substances, formed at decomposition of I, II, IV in dynamic vacuum. It was found, that the heating of I, II, IV in the ranges 150–800°C for I, 215–800°C for II, 180–800°C for IV affords the solid substances, containing alkaline-earth metals fluorides and iron oxides. Using topological analysis of the electron density distribution in I, III, V, intra- and intermolecular interactions were quantitatively estimated within the framework of Bader’s atoms in molecules theory. According to Espinosa–Mollins–Lecomte correlation, energies of the intermolecular interactions for I, III, V are close to the experimentally measured enthalpies of sublimation of related complexes published previously.

Copper(II) β-diketonates are popular MOCVD precursors for production of copper and copper-containing coatings. For further development and targeted design of new precursors of this type it would be very useful to have a tool for fast indirect estimation of the energy of Cu–O bonds. In this work, we have searched for correlations between the energy of Cu–O bonds in Cu(II) β-diketonates and their topological characteristics. Several equations have been proposed.

N,N'-((Hydrazine-1,2-diylidene-bis(methanylylidene))bis(2,1-phenylene))bis(4-methylbenzene-sulfonamide) (H₂L) and its binuclear complexes Zn₂L₂ and Co₂L₂ are synthesized. The compositions and structures of H₂L and its complexes are determined by elemental analysis and IR and ¹H NMR spectroscopy (for Zn₂L₂). The structures of H₂L and Co₂L₂ are determined by XRD (CIF files CCDC no. 2405868 for H₂L and no. 2390599 for Co₂L₂·4DMSO). The magnetic properties of Co₂L₂ and photoluminescence properties of H₂L and Zn₂L₂ are studied. The Zn(II) complex exhibits the photoluminescence properties in an acetonitrile solution and in the solid state ((lambda _{{{text{max}}}}^{{{text{fl}}}}) = 584 and 532 nm) with quantum yields of 0.06 and 0.68, respectively. The Co(II) complex exhibits the properties of slow magnetic relaxation.

Biphosphonium tetraiodomanganate(II) [DPEPhosMe₂]MnI₄ has been synthesized by the reaction of MnI₂ with bis(phosphonium) salt [DPEPhosMe₂]I₂, which is prepared by the alkylation of DPEPhos with methyl iodide. At ambient temperature, polycrystalline samples of [DPEPhosMe₂]MnI₄ exhibit bright green phosphorescence (λ_max = 546 nm) with a quantum yield of 77%. The phosphorescence decay lifetime is 45 μs, which is rather short for Mn²⁺-centered phosphorescence.

The reaction of di-, tri-, and tetraphenylcyclopentadienylpotassium with yttrium chloride tetrahydrofuranate in the presence of 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me₃tach) gives complexes of the type [Cp'Y(Me₃tach)Cl₂] (Cp' = Ph₂C₅H₃ (Cp^Ph2) (I), Ph₃C₅H₂ (Cp^Ph3) (II), Ph₄C₅H (Cp^Ph4) (III). The molecular structure of complexes I–III was established by X-ray diffraction (CCDC nos. 2406644 (I), 2406645 (II), 2406646 (III)). The main structural parameters of all of the obtained monocyclopentadienyl complexes were similar, irrespective of the number of phenyl substituents in the cyclopentadienyl ligand. According to NMR spectroscopy data, compounds I and III retained their structure in THF solution.

New chiral octahedral positively charged diastereomeric cobalt(III) complexes Λ(R,R)-1 and Δ(R,R)-1 with two asymmetric NNO-donor ligands (Schiff base of (1R,2R)-cyclohexanediamine and 4‑bromo-5-methylsalicylaldehyde) were synthesized. Single-crystal X-ray diffraction (XRD) analysis showed that the Δ(R,R)-1 complex is arranged in the crystal as a homochiral spiral with a “tube-in-tube” cavity, formed via hydrogen bonding between amino groups of the complex, water molecules, and the counterion. The bromo-containing complex Λ(R,R)-1 was further modified by a catalytic Suzuki–Miyaura cross-coupling reaction to give complexes Λ(R,R)-2 and Λ(R,R)-3 with introduced Ph and 4-CF₃C₆H₄ groups. The structure of complex Λ(R,R)-2 was confirmed by XRD. The catalytic activity of the synthesized complexes was studied in asymmetric phase-transfer alkylation and trimethylsilylcyanation reactions. Cobalt(III) complexes were also tested as chiral selectors for enantioselective voltammetric sensors, and the effect of complex structure on sensor characteristics toward the enantiomers of naproxen and thyroxine was evaluated.

The reaction between 1-(5-hydroxy-1-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl)ethan-1-one (L) and manganese(II) acetate afforded two new manganese(II) complexes with trans and cis configurations of the acylpyrazolone ligands—trans-L₂Mn(MeOH)₂ (trans-I) and cis-L₂Mn(MeOH)₂ (cis-I),—characterized by elemental analysis and X-ray diffraction (CCDC nos. 2408806 and 2408805, respectively). The less stable (cis-I) complex was obtained by introducing 2,2′-bipyridine into the reaction, presumably leading to the formation of an intermediate heteroleptic complex with L and 2,2′-bipyridine. The resulting isomeric complexes exhibit different molecular geometries and supramolecular organization in the crystal but convert into the more stable (trans-I) isomer in DMF solution. According to magnetometry and EPR spectroscopy, they display slightly different magnetic properties.

A series of dimeric indium(III) catecholates [(R-Cat)InI]₂ (R = 3,6-cHex (I), 3,5-tOc (II), 4-tOc (III), and 3,5-C(Me)₂Ph (IV)) is synthesized by the oxidative addition of indium(I) iodide to the following alkyl-substituted o-benzoquinones: 3,6-di-cyclo-hexyl-o-benzoquinone (3,6-cHex-Q), 3,5-di-tert-octyl-o-benzoquinone (3,5-tOc-Q), 4-tert-octyl-о-benzoquinone (4-tOc-Q), and 3,5-bis(2-phenylpropan-2-yl)-o-benzoquinone (3,5-C(Me)₂Ph-Q). Compounds I–IV are stable in the crystalline state and in solution, and their structures are confirmed by NMR and IR spectroscopy and elemental analysis. The crystallization of complex II from THF gives crystals of two types, cis-II·4THF and trans-II·4THF, corresponding to the cis and trans orientations of the alkyl substituents relatively to the catecholate fragment plane. The reactions of compounds I–IV with 2,2'-bipyridyl afford heteroleptic derivatives (R-Cat)InI(Bipy) (R = 3,6-cHex (V), 3,5-tOc (VI), 4-tOc (VII), and 3,5-C(Me)₂Ph (VIII)). Compounds V and VIII are isolated in the individual state and characterized by a set of physicochemical methods. Derivatives VI and VII are unstable and undergo further transformations to form a poorly separable mixture of products. The molecular structures of complexes cis-II·4THF and trans-II·4THF are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2404879 and 2404880, respectively).

The reaction of europium dibenzoylmethanate complex Na⁺[Eu(Dbm)₄]^– with 1-alkyl-4-dimethylaminopyridinium salts gives compounds [RNC₅H₄NMe₂]⁺[Eu(Dbm)₄]^– (Dbm = [PhC(O)CHC(O)–Ph]), where R = C₁₀H₂₁ (I) or a set of oligomers C_nH_2n+1, (n is even) ([(R-NC₅H₄NMe₂)]I) with a weight-average molecular weight M_w = 1520 (II). The molecular structure of complex I was established by X-ray diffraction analysis (CCDC no. 2405293). Compounds I and II were used as the luminescent components for a luminescent composite material based on low-density polyethylene (LDPE). The optical properties of complexes I and II and LDPE-based composite materials prepared using I and II were investigated.