Vol 42, No 5 (2016)

Data on the syntheses and studies of the structures and properties of different types of coordination compounds of lanthanides with 1,1-dithiolate ligands (tris(chelates), complex salts, and heteroligand compounds) are considered. The results on the application of these compounds as precursors for the syntheses of lanthanide sulfides and the data on the photoluminescence, magnetic, and some other properties of a series of the complexes are presented.

Two new Ln(III) metal-organic frameworks (MOFs) based on 5-nitroisophthalic acid (H₂L), namely [Pr₄(L)₆(H₂O)₄]_n (I) and [Gd(L)(FA)(H₂O)₂]_n (II) (HFA = formic acid), were prepared by solvothermal reactions and structurally characterized by IR, elemental analysis, XRD, and single crystal X-ray diffraction (CIF files CCDC nos. 971379 (I) and 971380 (II)). A 3D {4.6²}{4¹⁰.6¹⁷.8⁹}{4³}₂ topology framework of I and a 3D {4.6²₂}{4².6¹⁰.8³} topology network of II are constructed respectively with different synthetic conditions. Four kinds of coordination modes are observed for dicarboxylate in these two MOFs in total. Notably, the in situ hydrolysis of DMF solvates leads to the formation of formate ions that was observed in the structure of II. Moreover, the luminescent properties of both complexes and corresponding ligand have been investigated.

Two new mononuclear Schiff base zinc(II) complexes, [ZnCl₂(L¹)] ∙ MeOH (I) and [Zn(L²)₂] (II) (L¹ = 2-bromo-4-chloro-6-[(2-ethylammonioethylimino)methyl]phenolate; L² = 2-bromo-4-chloro-6-(isopropyliminomethyl)phenolate), have been prepared and characterized by elemental analyses, infrared and UV-Vis spectroscopy, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1408962 (I), 1408961 (II)). Complex I crystallizes in the triclinic space group \(P\overline 1\) with unit cell dimensions a = 9.859(1), b = 13.015(2), c = 19.817(3) Å, α = 73.591(2)°, β = 76.032(2)°, γ = 82.966(2)°, V = 2363.0(5) ų, Z = 4, R₁ = 0.0925, and wR₂ = 0.2257. Complex II crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.6387(7), b = 22.307(2), c = 21.443(2) Å, β = 96.216(3)°, V = 3632.4(6) ų, Z = 8, R₁ = 0.0651, and wR₂ = 0.1100. The both Zn atoms in I is four-coordinated in a tetrahedral geometry by the NO donor set of the Schiff base ligand, and two Cl ligands. The Zn atom in II is in a tetrahedral geometry by two N and two O atoms from two Schiff base ligands. Crystals of the complexes are stabilized by hydrogen bonds and weak π…π interactions. Fluorescence property of the complexes have been determined.

A new centrosymmetric mononuclear copper(II) complex [Cu(L)₂](ClO₄)₂ (I) and a new centrosymmetric mononuclear nickel(II) complex [Ni(L)₂(MeOH)₂](ClO₄)₂ (II), where L is the zwitterionic ligand 2-bromo-4-chloro-6-[(2-methylammonioethylimino)methyl]phenolate, have been prepared from the Schiff base 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol with copper perchlorate and nickel perchlorate, respectively. The complexes were characterized by elemental analysis, infrared spectra, and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1408054 (I) and 1407973 (II)). Complex I crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.7736(4), b = 21.608(1), c = 8.5194(4) Å, β = 93.907(2)°, V = 1427.7(1) ų, Z = 2, R₁ = 0.0546, and wR₂ = 0.1531. Complex II crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 21.324(3), b = 16.821(2), c = 9.425(1) Å, β = 90.114(2)°, V = 3380.5(7) ų, Z = 4, R₁ = 0.0693, and wR₂ = 0.1627. The Cu atom in I is in square planar coordination, and the Ni atom in II is in octahedral coordination.

An interesting discrete metallomacrocycle (MMC), [Zn₃(L)₃(H₂O)₆] · H₂O (I), has been prepared by means of self-assembly of Zn(II) salt, 5-hydroxyisophthalic acid (H₂L) as organic linker and 5,5’-(pyridine-2,6-diyl)diisophthalic acid (H₄L’) as structure-directing agentunder hydrothermal condition. In complex I, the planar trinuclearmetal-organic macrocycles are arranged into 2D sheet layers connected by strong hydrogen bonded between OH groups of the ligands. Then they stack into 3D supramolecular architecture in–ABAB–array way to give a small 1D open channel along the c axis (CIF file CCDC no. 1053024). Additionally, thermal stability and luminescence properties of I were also investigated.