Hybrid Cu-Containing Compounds Based on Lacunary Strandberg Anions: Synthesis under Mild Conditions, Crystal Structure, and Magnetic Properties.

A one-pot reaction of a copper source (metallic powder Cu0 or Cu2+ salts) and bpy (bpy = 2,2'-bipyridine) in the presence of (NH4)2HPO4 and (NH4)6Mo7O24·4H2O yields heterometallic hybrid compounds of the general type {[Cu(bpy)n(H2O)m]p[P2MoxOy]}. The structures exhibit a number of phosphomolybdate POMs including not only a common Strandberg anion [P2Mo5O23]6- but also its unprecedented bi- and trilacunary derivatives [P2Mo3O18]8- and [P2Mo2O15]8-. The structural determinants including the metal source (copper powder vs copper salts), counterion of the salts, and stoichiometry of the reagents were examined. An ex situ EPR study revealed the formation of different CuII complexes in the reaction mixture depending on the copper precursor. The obtained compounds have been found to possess selectivity toward the sorption of methylene blue in a mixture of organic dyes. DC magnetic measurements of 1-3 indicate rather strong antiferromagnetic metal-metal exchange interactions. Compound 1 exhibits field-induced slow magnetic relaxation in AC magnetic measurements, which is a rarely observed phenomenon among Cu(II) complexes.

Hybrid compound based on diethylenetriaminecopper(ii) cations and scarce V-monosubstituted ß-octamolybdate as water oxidation catalyst.

Herein, we report on a new hybrid compound (NH4){[Cu(dien)(H2O)2]2[ß-VMo7O26]}·1.5H2O (1), where dien = diethylenetriamine, containing an extremely rare mixed-metal pseudo-octamolybdate cluster. An ex situ EPR spectroscopy provided insights into the formation of paramagnetic species in reaction mixture and in solution of 1. The magneto-structural correlations revealed weak antiferromagnetic exchange interactions between the [Cu(dien)]2+ cations transmitted by intermolecular pathways. The cyclic voltammetry showed the one-electron process associated with the Cu3+/Cu2+ oxidation followed by the multi-electron catalytic wave due to water oxidation with a faradaic yield of 86%. The title compound was thus employed in homogeneous water oxidation catalysis using tris(bipyridine)ruthenium photosensitizer. At pH 8.0, efficiency of the catalytic system attained 0.19 turnovers per second supported by the relatively mild water oxidation overpotential of 0.54 V.

Chlorido-bis-(1,10-phenanthroline-κ(2) N,N')copper(II) chlorido-(1,10-phen-anthroline-κ(2) N,N')(pyridine-2,6-di-carboxyl-ato-κ(3) O (2),N,O (6))manganate(II) methanol monosolvate.

The title complex, [CuCl(C12H8N2)2][Mn(C7H3NO4)Cl(C12H8N2)]·CH3OH, consists of discrete [CuCl(phen)2](+) cations (phen is 1,10-phenanthroline), [MnCl(pydc)(phen)](-) anions (H2pydc is 2,6-pyridine-2,6-di-carb-oxy-lic acid) and one methanol solvent mol-ecule of crystallization per asymmetric unit. It should be noted, that a solvent-masking procedure as implemented in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst. 42, 339-341 ▶] was used to remove the electronic contribution from one disordered solvent molecule, presumably methanol. Only the atoms used in the refined model are reported in chemical formula and related values. The Cu(II) ion is five-coordinated by two phenanthroline ligands and one chloride ion in a distorted trigonal-bipyramidal geometry. The dihedral angle between the phen ligands is 65.21 (5)°. The Mn(II) ion is six-coordinated by one Cl atom, two N atoms from a phen ligand, as well one N atom and two O atoms from pydc in a distorted octa-hedral coordination geometry, with cis angles ranging from 72.00 (8) to 122.07 (8)° and trans angles ranging from 143.98 (8) to 163.15 (6)°. In the crystal, C-H⋯O, O-H⋯O and C-H⋯Cl hydrogen bonds, cation-anion π-π inter-actions between the phen ring systems with centroid-centroid distances in the range 3.881 (34)-4.123 (36) Å, as well as cation-cation, anion-anion π-π inter-actions between the phen rings with centroid-centroid distances in the range 3.763 (4)-3.99 (5) Šand pydc rings with centroid-centroid distances 3.52 (5) Šlink the various components.