Three metal(II) complexes constructed using the 2-(1H-benzo[d]imidazol-2-yl)quinoline ligand

2-(1H-benzo[d]imidazol-2-yl)quinoline (BQ) as ligand and three coordination compounds of formula {Zn(BQ)Cl2} (1), {Pb(BQ)Cl2} n (2) and {[Cu(BQ)2(OC(O)CH3)]OC(O)CH3 · CH3COOH} (3) have been synthesized and fully characterized. The complexes crystallize in triclinic space group P 1 ‾ $P‾{1}$ . In complexes 1 and 2, the coordination geometry is a distorted tetrahedral environment around the zinc center and a distorted sixfold coordination geometry around the lead center, respectively. In complex 3 the central Cu(II) center is in a trigonal bipyramidal coordination geometry. The Cu(II) ion is surrounded by two bidentate 2-(2′-quinolyl)benzimidazole (BQ) ligands and one coordinated acetate molecule. One further acetate anion associated by a strong hydrogen bond with a molecule of acetic acid balances the charge of the compound.

Strong Coupling and Slow Relaxation of the Magnetization for an Air-Stable [Co4] Square with Both Tetrazine Radicals and Azido Bridges

Introducing both tetrazine radical and azido bridges afforded two air-stable square complexes [M^II₄(bpztz^•-)₄(N₃)₄] (M^II = Zn²⁺, 1; Co²⁺, 2; bpztz = 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine), where the metal ions are cobridged by μ_1,1-azido bridges and tetrazine radicals. Magnetic studies revealed strong antiferromagnetic metal-radical interaction with a coupling constant of -64.7 cm^-1 in the 2J formalism in 2. Remarkably, 2 exhibits slow relaxation of magnetization with an effective barrier for spin reverse of 96 K at zero applied field.

Two azido-bridged [2×2] cobalt(ii) grids featuring single-molecule magnet behaviour

Two Co(ii) [2 × 2] grid-like clusters containing both pyridazine and azido bridges were reported to exhibit overall intramolecular ferromagnetic coupling and field-induced single-molecule magnet behavior with the effective energy barriers up to 56 K.

Magneto-structural correlations in Ni(ii) [2 × 2] metallogrids featuring a variable number of μ-aquo or μ-hydroxo extra bridges

Cationic [2 × 2]-grids of nickel(ii) and dppn exhibit strong intramolecular antiferromagnetic interactions due to complementary effects between pyridazine and aquo/hydroxo bridges.

Click Chemistry Derived Pyridazines: Electron-Deficient Building Blocks with Defined Conformation and Packing Structure

A series of 3,6-bis(4-triazolyl)pyridazines equipped with terminal phenyl substituents with varying degree of fluorination were synthesized by using the facile copper-catalyzed azide-alkyne cycloaddition and their structures were thoroughly investigated in the gas phase, in solution, and in the solid state by employing DFT calculations, NMR spectroscopy, and single-crystal X-ray diffraction, respectively. On the molecular level, their structure is governed by the strong preference of the triazole-pyridazine linkages for the anti-conformation. The supramolecular organization of the molecules in the crystalline solid is controlled by π-stacking, C-H⋅⋅⋅π as well as C-F⋅⋅⋅H interactions. The latter can conveniently be tuned by the number and position of fluorine substituents in the terminal phenyl units, giving rise to either herringbone-like, 1D or 2D lamellar packing. Electrochemistry and optical spectroscopy of all compounds suggest that they might find use as electron-transporting/hole-blocking materials in organic electronics.