Taming Copper(I) Cyanate and Selenocyanate with N‐Heterocyclic Carbenes

Heteroleptic Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes: Structural Characterization, Computational Analysis, Tyrosinase Inhibitory, and Biological Effects

Derivatization of (NHC)M-Cl (M = Ag, Au) with selected sulfur donors from the family of dialkyldithiophosphates and bis(2-mercapto-1-methylimidazolyl)borate ligands gave a series of heteroleptic mononuclear complexes. In single-crystal X-ray diffraction analysis, Ag(I) complexes adopted a trigonal planar geometry, while Au(I) complexes are near-linear. TD-DFT and hole-electron analyses of the selected complexes gave insight into the electronic features of the metal complexes. In vitro cellular tests were conducted on the human cancerous breast cell line MCF-7 using 2 and 8. The antibacterial activities of complexes 1, 2, 3, 7, 8, and IPr-Ag-Cl were also screened against Gram-positive (Staphylococcus aureus PTCC 1112) and Gram-negative (Escherichia coli PTCC 1330) bacteria. Antityrosinase and hemolytic effects of the selected compounds were also determined.

Redox-Neutral Transformations of Carbon Dioxide Using Coordinatively Unsaturated Late Metal Silyl Amide Complexes

Two-coordinate silylamido complexes of nickel and copper rapidly react with CO₂ to selectively form a new cyanate ligand along with hexamethyldisiloxane byproducts. Mechanistic insight into these reactions was obtained from the synthesis of proposed intermediates, several silyl- and phenyl- substituted amido analogues, and their subsequent reactivity with CO₂. These studies suggest that a unique intramolecular double silyl transfer step facilitates CO₂ deoxygenation, which likely contributes to the rapid rates of reaction. The deoxygenation reactions create a platform for a synthetic cycle in which copper amido complexes convert CO₂ to organic silylcarbamates.

Structural trends in a series of bulky dialkylbiarylphosphane complexes of CuI

Cu^I complexes containing the bulky dialkylbiarylphosphane 2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl (^tBuXPhos, L) and an ancillary ligand (Cl^-, Br^-, I^-, MeCN, ClO₄^- or SCN^-) have been structurally characterized, namely, chlorido[2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP]copper(I), [CuCl(C₂₉H₄₅P)], 1, bromido[2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP]copper(I), [CuBr(C₂₉H₄₅P)], 2, [2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP]iodidocopper(I), [CuI(C₂₉H₄₅P)], 3, (acetonitrile-κN)[2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP]copper(I) hexafluoridophosphate, [Cu(CH₃CN)(C₂₉H₄₅P)]PF₆, 4, [2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP](perchlorato-κO)copper(I), [Cu(ClO₄)(C₂₉H₄₅P)], 5, and di-μ-thiocyanato-κ²S:N;κ²N:S-bis{[2-(di-tert-butylphosphanyl)-2',4',6'-triisopropylbiphenyl-κP]copper(I)}, [Cu₂(NCS)₂(C₂₉H₄₅P)₂], 6. Iodide complex 3 shows significant Cu^I-arene interactions, in contrast to its chloride 1 and bromide 2 counterparts, which is attributed to the weaker interaction between the iodide ion and the Cu^I centre. When replacing iodide with an acetonitrile (in 4) or perchlorate (in 5) ligand, the reduced interaction between the Cu^I atom and the ancillary ligand results in stronger Cu^I-arene interactions. No Cu^I-arene interactions are observed in dimer 6, due to the tricoordinated Cu^I centre having sufficient electron density from the coordinated ligands.

Formation of a nona-nuclear copper(II) cluster with 3,5-di-methyl-pyrazolate starting from an NHC complex of copper(I) chloride

The complete nona-nuclear cluster in bis-[1,3-bis-(2,6-di-methyl-phen-yl)imid-azol-ium] di-μ-chlorido-tetra-chlorido-octa-kis-(μ-3,5-di-methyl-pyrazolato)hexa-μ3-hydroxido-nona-copper(II) chloro-form disolvate, [HIXy]2[Cu9(μ-pz*)8(μ3-OH)6(μ2-Cl)2Cl4]·2CHCl3 or (C19H21N2)2[Cu9(C5H7N2)8Cl6(OH)6]·2CHCl3, where pz* is the 3,5-di-methyl-pyrazolyl anion, C5H7N2 -, and HIXy is the 1,3-bis-(2,6-di-methyl-phen-yl)imidazolium cation, C19H21N2 +, is generated by a crystallographic centre of symmetry with a square-planar CuII ion bound to four μ3-OH ions lying on the inversion centre. Of the four remaining unique CuII atoms, three adopt CuN2O2Cl square-pyramidal coordination geometries with the chloride ion in the apical position and one has a distorted CuN2OCl tetra-hedral geometry. The dianionic nona-nuclear core can be described as a 24-membered [CuNN]8 ring that contains a Cu9O6Cl6 core. The cluster features three intra-molecular O-H⋯Cl hydrogen bonds. In the crystal, weak C-H⋯N and C-H⋯Cl inter-actions link the components. Polynuclear paramagnetic clusters of this type are of considerable inter-est due to their relevance to both the bioinorganic and single-mol-ecule magnets research fields.