Open Access
Access granted
Subscription Access
Vol 45, No 3 (2019)
- Year: 2019
- Articles: 9
- URL: https://bakhtiniada.ru/1070-3284/issue/view/13361
Article
Controlled Molecular Magnetism of Bi- and Polynuclear Transition Metal Complexes Based on Hydrazones, Azomethines, and Their Analogs
Abstract
The possibilities of the magnetochemical method for the description of structures and properties of bi- and tetranuclear metallochelates and supramolecular architectures based on coordination compounds with restricted types of ligand systems, mainly hydrazones, azomethines, and their analogs, are reviewed. The known published data for the bi- and polynuclear complexes, whose paramagnetic centers are bound by both intra- and intermolecular exchange interactions, are systematized. A relationship between specific features of the electronic and geometric structures of the complexes and the character of the exchange effects is considered. Magnetostructural relations in the discussed compounds are systematized. The compounds discussed are important model objects for the development of the strategy for the targeted design of one-, two-, and three-dimensional magnetically ordered structures.
163-187
Template Synthesis of Tin(IV) Complexes with Tridentate Iminopyridine Ligands
Abstract
Six-coordinate metal complexes containing tridentate Schiff bases with an ONN-chelating moiety were prepared by template synthesis on tin tetrachloride using various aminophenols and α-carbonyl-substituted pyridines. The structures of five compounds were studied by X-ray diffraction (CIF files CCDC nos. 849152–1849156). The UV/Vis spectra of the obtained series of compounds were found to be highly sensitive to the nature of substituents in the moieties of organic ligand.
188-199
Synthesis and Crystal Structure of [Co(DmgH)2(Thio)2]2F[PF6]. The Effect of Fluorine-Containing Co(III) Dioximates on the Physiological Processes of the Microalga Porphyridium cruentum
Abstract
New fluorine-containing cobalt(III) dioximates [Co(DmgH)2(Thio)2]2F[PF6] (I) and [Co(DmgH)2(Sam)2]2[TiF6] · 4H2O (II) (DmgH = dimethylglyoxime monoanion, Thio = thiourea, Sam = sulfanilamide) were obtained. The structure of I was determined by X-ray diffraction (CIF file CCDC no. 1852216). The crystals are cubic, space group Pn\(\bar {3}\)n. The octahedral coordination polyhedron of the metal is formed by the N4S2 set of donor atoms of two DmgH¯ ligands and two Thio molecules. The effect of compounds I and II and two previously described compounds of this class with fluorine anions, [Co(DmgH)2(Thio)2]2[TiF6] · 2H2O (III) and [Co(DmgH)2(An)2]2[ZrF6] (IV) (An = aniline), on the physiological processes of the red microalga Porphyridium cruentum was studied. Complex III in concentration of 20 mg/L increased the microalga productivity by 20% and lipid biosynthesis by 17% and can be proposed for biotechnology applications.
200-207
Crystal Structure of Mono- and Trinuclear Ni(II) Complexes with Bis-Azomethine Based on 2-Amino-3-Formylpyridine
Abstract
The structure of a new mononuclear nickel(II) complex with bis-azomethine [Ni(H2L)]+ · CH3COO– · H2O, resulting from condensation of 1,3-diaminopropan-2-ol with 2-amino-3-formylpyridine (H3L), was studied by X-ray diffraction (CIF files CCDC nos. 1562927, 1562928). Apart from the mononuclear complex, the reaction gave a minor amount of the trinuclear metal chelate [Ni3L'(H2O)2]+ · (CH3COO)– · CH3OH · H2O, where L' is N5O2-donor ligand containing two 3-(((2-aminopyridin-2-yl)methylene)amino)-1-aminopropan-2-ol moieties linked by a 2-aminopyridine-3-methylene group.
208-214
Crystal Structure and Properties of [Co(NH3)6][PdCl4]Cl
Abstract
Complexes [Co(NH3)6][PdCl4]Cl (I) and [Co(NH3)6]2[PtCl4]3 (II) are synthesized and characterized. Complex I is isolated for the first time. The compositions and structures of the complexes are confirmed by X-ray structure analysis (CIF file CCDC no. 1830657), X-ray diffraction analysis, IR spectroscopy, and elemental analysis. The thermal decomposition of complex I in air gives the three-phase product: Pd (space group Fm3m), PdO (space group P\(\bar {4}\)n2), and Co3О4 (space group Fd3m). The two-phase product consisting of metallic platinum Pt (space group Fm3m) and cobalt oxide Co3О4 (Fd3m) is formed as a result of the thermal decomposition of complex II is revealed that the single-phase product (a solid solution based on the noble metal and cobalt) can be obtained by the thermal decomposition of the corresponding binary complexes in a hydrogen flow or by chemical reduction using a solution of N2H4 · HCl.
215-221
Two cis-Dioxomolybdenum(VI) Complexes with Tridentate ONO Aroylhydrazone Schiff Bases: Syntheses, Characterization, Crystal Structures, and Catalytic Epoxidation Property
Abstract
Two new cis-dioxomolybdenum(VI) complexes, [MoO2(L1)MeOH] (I) and [MoO2(L2)MeOH] (II) with potentially tridentate ONO aroylhydrazone Schiff bases derived from 3-methoxysalicylaldehyde with 4-bromobenzohydrazide and 4-trifluoromethylbenzohydrazide, respectively, have been synthesized and fully characterized on the basis of elemental analysis, FT-IR, molar conductivity, and electronic spectra. Structures of the complexes have been accomplished by single crystal X-ray diffraction (СIF files CCDC nos. 1433352 (I) and 1433318 (II)). The complexes have distorted octahedral structures in which the aroylhydrazones behave as binegative ligands. It is also revealed from the crystal structures that the Mo(VI) center adopts NO5 donor environment, and the octahedral coordination is furnished by two oxido groups and oxygen atoms of methanol or deprotonated methanol molecules. The catalytic properties were investigated for epoxidation of cyclooctene using aqueous tert-butyl hydroperoxide as the oxidant.
222-229
Synthesis, Crystal Structure, and Magnetic Property of four Manganese(II) Complexes with Bulky Schiff bases Derived from Amantadine and Rimantadine
Abstract
The reactions of manganese(II) chloride tetrahydrate and four bulky Schiff base ligands derived from amantadine (or rimantadine) and salicylaldehyde (or 4-methoxysalicylaldehyde) generated four novel complexes, C34H42Cl2MnN2O2 (I), C36H46Cl2MnN2O4 (II), C38H50Cl2MnN2O2 (III), and C40H54Cl2MnN2O4 (IV), respectively. These complexes were characterized by melting point, infrared spectra, elemental analysis, magnetic susceptibility, molar conductance and single-crystal X-ray diffraction (CIF files CCDC nos. 1 540 253 (I), 1 540 254 (II), 1 540 255 (III), 1 540 256 (IV)). Single-crystal X-ray diffraction analysis reveals that I, III and IV crystallize in the orthorhombic system with space groups P212121, Pbcn and Pcan, respectively, whereas II crystallizes in the monoclinic system with space group P21/n. Each asymmetric unit for I–IV consists of one manganese(II) atom, two Schiff base ligands and two chlorine atoms. The central manganese(II) atoms lie on a twofold rotation axis in III and IV, whereas manganese(II) atoms lie on general positions in I and II. In these complexes molecules, manganese(II) atoms is four-coordinated via two chlorine atoms and two oxygen atoms from the corresponding Schiff base ligands, forming a distorted tetrahedral geometry.
230-237
Two Rare-Earth Complexes (Sm, La) Based on a Carbon-Bridged Bis(phenolate): Synthesis and Crystal Structures
Abstract
Two rare earth metal complexes based on the carbon-bridged bis(phenolate) ligand, 2,2'-methylene-bis(6-tert-butyl-4-methyl-phenoxo) (LH2), have been synthesized. Reaction of LH2 with (C5H5)3Sm(THF) in a 1.5 : 1 molar ratio in THF at 50°C produced rare earth metal bis(phenolate) complex (C5H5)Sm(L)(THF)2 (I) in almost quantitative yields. Complex I reacted with 0.5 molar ratio of LH2 in toluene at 80°C afforded (L)Sm(LH)(THF)2 (II) as the final product in good yield. Reaction of LNa2 with LaCl3 in a 2 : 1 molar ratio in THF at room temperature produced hetero-nuclear rare earth metal bis(phenolate) complex (L)La(LH)(THF)2Na(THF)2 (III). In addition, II and III were characterized by X-ray single-crystal diffraction analysis (CIF file CCDC nos. 1500917 (II) and 1826699 (III)) as well as characterizations including elemental analyses and IR spectra of both complexes. Furthermore, detail reasons of the difference of structures are presented. The ionic radii of the rare earth metal plays a significant role in the structure difference of two complexes.
238-243
Synthesis, Crystal Structure, and Biological Activity of Two Complexes based on 5-hydroxy-4′-methoxyisoflavone-3′-sulfonate
Abstract
Two metal complexes [Mn(H2O)6(C16H11O7S)2] · 2H2O (I) and Al(H2O)3(C16H11O7S) · 2H2O (II) were synthesized by reaction of the sodium 5-hydroxy-4′-methoxyisoflavone-3′-sulfonate (C16H11O7SNa) with MnSO4 · 4H2O or Al(NO3)2 · 6H2O, respectively. Complex I and II were characterized by the single crystal X-ray diffraction (CIF files CCDC nos. 1563980 (I), 1563981 (II)), IR spectroscopy, thermogravimetric and elemental analysis. For complex I, the coordination number of Mn(II) is 6 and the coordinated atoms are all oxygen atoms from six H2O molecules. For complex II, the coordination number of Al(III) is 4, and coordinated atoms come not only from three water molecules but also the sulfo-group. Furthermore, I and II have hydrogen bonding and π···π stacking supramolecular interactions. Hydrogen bonding forms a hydrophilic region, π···π stacking forms a hydrophobic region. The sulfo-group is a vital bridge between the hydrophilic region and the hydrophobic region, which improves the water-soluble ability and prompts the versatile assembly of pallidiflorin with metal ion. In addition, the preliminary biological test showed that I, II had antimicrobial activities.
244-252