Bis[μ-3,5-bis-(2-pyrid-yl)pyrazolato]bis-(hydrogensulfato)-dicopper(II) methanol disolvate

Oxygen Activation by a Copper Complex with Sulfur-Only Coordination Relevant to the Formylglycine Generating Enzyme

Synthesizing hydrosulfido Cu thiolate complexes is quite challenging. In this report, two new and rare hydrosulfido Cu thiolate complexes, [Et₄N]₂[(mnt)Cu-SH] (2, mnt = maleonitrile dithiolene = S₂C₂(CN)₂) and [Et₄N]₃[(mnt)Cu-(μ-SH)-Cu(mnt)] (3), have been synthesized. Coordination sites and O₂ activation by complex 2 resemble the formylglycine generating enzyme (FGE), an enzyme recently crystallographically characterized with sulfur-only coordination around Cu (three thiolate ligands). The function of this enzyme (and complex 2) is surprising because vulnerable thiolates should not be well suited for O₂ activation rationally. Indeed, activation of oxygen by such an all-sulfur-coordinated Cu complex 2 is lacking in the literature. Aerial O₂ (ambient O₂ from the air) activation by complex 2 could proceed through a superoxide radical intermediate and a sulfur radical intermediate detected by resonance Raman (rR) spectroscopy and electron paramagnetic resonance (EPR) spectroscopy, respectively. The chemistry of 2 has been examined by its reactivity, crystal structure, and spectroscopic and cyclic voltammetric analyses. In addition, the results have been complemented with density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations.

A Computational Study of Metallacycles Formed by Pyrazolate Ligands and the Coinage Metals M = Cu(I), Ag(I) and Au(I): (pzM)n for n = 2, 3, 4, 5 and 6. Comparison with Structures Reported in the Cambridge Crystallographic Data Center (CCDC)

The structures reported in the Cambridge Structural Database (CSD) for neutral metallacycles formed by coinage metals in their valence (I) (cations) and pyrazolate anions were examined. Depending on the metal, dimers and trimers are the most common but some larger rings have also been reported, although some of the larger structures are not devoid of ambiguity. M06-2x calculations were carried out on simplified structures (without C-substituents on the pyrazolate rings) in order to facilitate a comparison with the reported X-ray structures (geometries and energies). The problems of stability of the different ring sizes were also analyzed.

Supramolecular self-assembled coordination architecture composed of a doubly bis(2-pyridyl)pyrazolate bridged dinuclear CuII complex and 7,7′,8,8′,-tetracyano-p-quinodimethanide radicals

A tetranuclear Cu^II complex composed of a doubly bpypz⁻ bridged dinuclear Cu^II complex with TCNQ˙⁻ self-assembles into a 3D supramolecular coordination architecture via complementary weak coordination bonding and π-stacking interactions.

Versatile coordination architectures of products generated by the in situ reaction of a doubly bis(2-pyridyl)pyrazolate bridged dinuclear copper(ii) complex with tetracyanoethylene

Reaction of doubly bpypz⁻ bridged Cu(ii) dinuclear complex and TCNE gave three versatile coordination assemblies with TCNE solvolysis derivatives, depending on reaction solvents.

Bis[μ-3,5-bis-(pyridin-2-yl)pyrazolato]bis-[(hexa-fluoro-phosphato)copper(II)]

The title dinuclear complex mol-ecule, [Cu2(C13H9N4)2(PF6)2], lies about an inversion center. The Cu(II) atom shows a square-pyramidal coordination geometry with the basal plane formed by four N atoms of the two bis-chelating 3,5-bis-(pyridin-2-yl)pyrazolate ions and with one F atom of the hexa-fluoro-phosphate ion in the apical position. Mol-ecules are stacked in a column along the a axis through C-H⋯F hydrogen bonds. The columns are further linked by other C-H⋯F hydrogen bonds, forming a three-dimensional network.