New Coordination Polymers of Selected Lanthanides with 1,2-Phenylenediacetate Linker: Structures, Thermal and Luminescence Properties.

Solvothermal reactions of lanthanide (III) salts with 1,2-phenylenediacetic acid in N,N'-dimethylformamide (DMF) solvent lead to the formation of the metal complexes of the general formula Ln2(1,2-pda)3(DMF)2, where Ln(III) = Pr(1), Sm(2), Eu(3), Tb(4), Dy(5), and Er(6), 1,2-pda = [C6H4(CH2COO)2]2-. The compounds were characterized by elemental analysis, powder and single-crystal X-ray diffraction methods, thermal analysis methods (TG-DSC and TG-FTIR), infrared and luminescence spectroscopy. They exhibit structural similarity in the two groups (Pr, Sm, and Eu; Tb, Dy, and Er), which was reflected in their thermal behaviours and spectroscopic properties. Single-crystal X-ray diffraction studies reveal that Sm(2) and Eu(3) complexes form 2D coordination polymers with four crystallographically independent metal centers. Every second lanthanide ion is additionally coordinated by two DMF molecules. The 1,2-phenylenediacetate linker shows different denticity being: penta- and hexadentate while carboxylate groups exhibit bidentate-bridging, bidentate-chelating, and three-dentate bridging-chelating modes. The infrared spectra reflect divergence between these two groups of complexes. The complexes of lighter lanthanides contain in the structure coordinated DMF molecules, while in the structures of heavier complexes, DMF molecules appear in the inner and outer coordination sphere. Both carboxylate groups are deprotonated and engaged in the coordination of metal centers but in different ways in such groups of complexes. In the groups, the thermal decomposition of the isostructural complexes occurs similarly. Pyrolysis of complexes takes place with the formation of such gaseous products as DMF, carbon oxides, ortho-xylene, ethers, water, carboxylic acids, and esters. The complexes of Eu and Tb exhibit characteristic luminescence in the VIS region, while the erbium complex emits NIR wavelength.

Two Related Copper(I) π-Complexes Based on 2-Allyl-5-(2-pyridyl)-2H-tetrazole Ligand: Synthesis and Structure of [Cu(2-apyt)NO3] and [Cu(2-apyt)(H2O)](BF4) Compounds.

By means of the alternating current electrochemical technique two new π-compounds [Cu(2-apyt)NO3] (1) and [Cu(2-apyt)(H2O)](BF4) (2) have been obtained starting from the mixture of 1-allyl-5-(2-pyridyl)-2H-tetrazole (1-apyt), 2-allyl-5-(2-pyridyl)-2H-tetrazole (2-apyt) and corresponding copper(II) salts, and have been structurally studied. Selective complexation towards 2-allyl- isomer results in a formation of 2-apyt complexes. Copper(I) ion in both 1 and 2 complexes coordinates the allylic C=C bond, one pyridyl and one tetrazole N atoms. In both structures Cu+ center adopts distorted tetrahedral surrounding which additionally includes oxygen of NO3(-) in 1 and H2O moiety in 2. Structure 1 is built from [Cu(2-apyt)NO3]2 dimeric fragments. Contrary, participation of H2O in the metal coordination in 2 leads to the infinite {[Cu(2-apyt)(H2O)]+}n chain construction. To analyze interactions between the particles in 1 and 2 Hirshfeld surface analysis was performed.

Heterometallic Cu/Co and Cu/Co/Zn complexes bearing rare asymmetric tetranuclear cores: synthesis, structures, and magnetic and catalytic properties toward the peroxidative oxidation of cycloalkanes.

The three novel heterometallic complexes [CuCo(III)Co(II)(2)(MeDea)(3)Cl(3)(CH(3)OH)(0.55)(H(2)O)(0.45)](H(2)O)(0.45) (1), [CuCo(III)Zn(2)(MeDea)(3)Cl(3)(CH(3)OH)(0.74)(H(2)O)(0.26)](H(2)O)(0.26) (2), and [CuCo(III)Zn(2)(MeDea)(3)Cl(3)(DMF)] (3) have been prepared using a one-pot reaction of copper powder with cobalt chloride (1) and zinc nitrate (2, 3) in a methanol (1, 2) or dimethylformamide (3) solution of N-methyldiethanolamine. A search of the Cambridge Structural Database shows that the tetranuclear asymmetric cores M(4)(µ(3)-X)(µ-X)(5) of 1-3 represent an extremely rare case of M(4)X(6) arrays. The magnetic investigations of 1 disclose antiferromagnetic coupling in a Co(II)-Cu(II)-Co(II) exchange fragment with J(Co-Cu)/hc = -4.76 cm(-1), J(Co-Co)/hc = -2.76 cm(-1), and D(Co)/hc = +34.3 cm(-1). Compounds 1-3 act as precursors for the mild peroxidative oxidation of cyclohexane to cyclohexanol and cyclohexanone with overall yields up to 23%. The synthetic and structural features as well as the thermogravimetric behavior and electrospray ionization mass spectrometry data are discussed.

First Silver(I) - Complexes with Tetrazole Allyl Derivatives. Synthesis and Crystal Structure of [Ag2(C10H10N4S)2(H2O)2](BF4)2 and [Ag(C10H9ClN4S)(NO3)] π-Compounds (C10H10N4S and C10H9ClN4S - 5-(Allylthio)-1-phenyl- and 5-(Allylthio)-1-(4-chlorophenyl)-1H-tetrazole).

Crystalline silver(I) π complexes [Ag2(atpt)2(H2O)2](BF4)2 (1) (atpt - 5-(allylthio)-1-phenyl-1H-tetrazole (C10H10N4S)) and [Ag(atcpt)(NO3)] (2) (atcpt - 5-(allylthio)-1-(4-chlorophenyl)-1H-tetrazole (C10H9ClN4S)) complexes have been obtained using silver salt and the organic ligands. Compounds were characterized by X-ray single crystal diffraction: for 1 space group P21/n, a = 10.4560(5), b = 11.4008(5), c = 12.7550(7) Å, ß = 98.128(3)°, V = 1505.21(13) Å3 at 200 K, Z = 2; for 2: space group P21/a, a = 8.6790(8), b = 13.7324(10), c = 12.4597(13) Å, ß = 102.288(5)°, V = 1451.0(2) Å3 at 200 K, Z = 4. In both structures silver(I) atoms possess a trigonal pyramidal coordination environment with essentially different coordination modes of organic ligands. The Ag(I) arrangement in 1 involves the N3 and N4 atoms of two adjacent atpt molecules, an olefin C=C bond and a water molecule at the apical position. In crystal structure of 2 two O atoms from NO3- anions occupy two equatorial position of silver(I) coordination polyhedron, and atcpt is attached to the metal centre through the N4 atom of tetrazole core only. The weakly bound C=C bond is located at the apical position of Ag(I) environment.