Том 42, № 1 (2016)

Six new Cu(II), Ni(II) and Co(II) macroacyclic Schiff base complexes [M^II(H₂L)](ClO₄)₂ (L = L¹ and L²) (I–VI) were prepared by the reaction of two new N₂O₄ Schiff base ligands in equemolar ratios. The ligands H₂L¹ and H₂L² were synthesized by reaction of 2-[2-(2-formyl phenoxy)ethoxy]benzaldehyde (A¹) and/or 2-[2-(3-formylphenoxy)propoxy]benzaldehyde (A²) and ethanol amine and characterized with IR and ¹H, ¹³C NMR spectroscopy. All complexes were characterized by microanalysis, IR and mass spectrometry, whereas complex I was also characterized by single crystal X-ray (CIF file CCDC no. 1020055). The X-ray structure of complex I revealed that all nitrogen and oxygen atoms of ligand (N₂O₄) have coordinated to the metal ion. However, Cu²⁺ ion is in six coordination environment that can bedescribed as a distorted octahedral geometry.

Conditions for the synthesis of gallium isopropoxide (I) by anodic dissolution of the metal in i-PrOH (in the presence of Bu₄NBr supporting electrolyte) and by exchange reaction of GaCl₃ with i-PrONa were studied. In the latter case, the crude product was a waxy substance (II) infinitely soluble in the alcohol and hydrocarbons and containing 12–30% Cl, which cannot be removed by adding an excess of i-PrONa due to the formation of insoluble NaGa(OPr-i)₄. During 1.5–2 months, II is solidified to give non-melting nonvolatile amorphous product (III) poorly soluble in the alcohol. Upon heat treatment of II in vacuum, compound I is distilled off as an oily liquid consisting, according to mass spectrometry, of [Ga(OPr-i)₃]₂ dimer molecules. It can be retained for a long period of time in the presence of the [Ga(OPr-i)₃]₄ tetramer crystals. The existence of oligomeric molecules of different size up to polymers (“coordination polymerism”) in the materials is related to the possibility of tetrahedral or octahedral coordination of the metal atom. From concentrated solutions of components, the oxoalkoxochloride [Ga₅(µ₅-O)(µ-OPr-i)₈Cl₅] (IV) is crystallized. Its molecule is a flattened tetragonal pyramid. The equatorial plane formed by four gallium atoms has the µ₅-O group at the center. The axial Ga atom has an octahedral coordination. All eight sides of the pyramid are drawn together by the µ-OPr-i groups, and the chlorine atoms occupy the terminal positions. (CIF file CCDC no. 693282.)

A reaction of dimercury(I) dinitrate with nitrilotris(methylenephosphonic acid), N(CH₂PO₃)₃H₆, gave the complex [(Hg₂)₂(H₂O){N(CH₂PO₃)₃H₂}] · H₂O. The crystals of the complex are triclinic, space group \(P\bar 1\), Z = 2, a = 8.3436(3), b = 9.0744(3), c = 11.1124(4) Å, α = 91.875(3)°, β = 104.452(3)°, γ = 92.195(3)° (CIF file CCDC no. 1051860). The atoms of either dimercury cation are coordinated differently, making up a distorted tetrahedron and a distorted trigonal bipyramid. The ligand is coordinated to the Hg atoms through seven donor atoms: six (out of nine) O atoms and a N atom. The coordination involves the formation of chelate rings: two four-membered, three five-membered, a six-membered, and an eight-membered ring (CIF file CCDC no. 1051860).

A new centrosymmetric mononuclear nickel(II) complex, [Ni(L^a)₂] (I), and a new mononuclear zinc(II) complex, [Zn(L^b)(N₃)(AMP)] (II) (L^a = 2-iminomethyl-4-methylphenolate, L^b = 4-methyl-2-[(4-methylpyridin-2-ylimino)methyl]phenolate, AMP = 2-amino-4-methylpyridine), have been prepared and characterized by elemental analysis, IR and UV-Vis spectra, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1059023 (I) and 1059024 (II)). Complex I crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 16.067(2), b = 5.7222(6), c = 7.9004(9) Å, β = 92.471(4)°, V = 725.7(1) ų, Z = 2, R₁ = 0.0298, and wR₂ = 0.0695. Complex II crystallizes in the triclinic space group \(P\bar 1\) with unit cell dimensions a = 7.649(1), b = 10.414(2), c = 13.903(3) Å, α = 106.896(2)°, β = 91.581(2)°, γ = 103.033(2)°, V = 1027.3(4) ų, Z = 2, R₁ = 0.0372, and wR₂ = 0.0823. The Ni atom in I is in a square planar coordination, and the Zn atom in II is in a tetrahedral coordination. Crystals of the complexes are stabilized by hydrogen bonds and p···p interactions.

Four Cd-based complexes with chemical formulae [Cd(L¹)₂(2,2'-Bipy)(H₂O)] (I), [Cd(L²)₂(2,2'-Bipy) · 2H₂O] (II), [Cd(L¹)₂(Phen)(H₂O)] (III), {[Cd(L¹)₂(H₂O)(4,4'-Bipy)] · 3H₂O} (IV) (HL¹ = 3-(4-hydroxyphenyl)propanoic acid, HL² = p-hydroxyphenylacetic acid, Phen = phenantroline), have been synthesized and structurally characterized (CIF file CCDC nos. 1044844 (I), 1044844 (II), 1044844 (III), 1044847 (IV)). Single-crystal X-ray analyses reveal that compounds I and III have mononuclear Cd(II) units linking by three carboxylate groups, complex II shows dinuclear motif, whereas IV exhibits 1D chain constructed by bridging 4,4'-Bipy ligand. The assistant effect of chelating N-donor ligands with 2,2'-Bipy and Phen bind and bridging 4,4'-Bipy, as well as the flexibility of carboxylate, play an important to modulate on the resulting motifs. The detailed analyses of Hirshfeld surface and fingerprint plots provide insight into the nature of non-covalent interactions in the title compounds. Furthermore, the luminescent properties of the all compounds were discussed in detail.