Structural characterization of 1:1 adducts of silver(I) (pseudo-) halides (AgX, X=NCO, Cl, Br, I) with Ph2E(CH2)EPh2 (E=P, As) (‘dp(p/a)m’) and 4:3 adducts of copper(I) halide (CuX, X=Cl, Br, I), containing trinuclear cations, of the form [X2Ag3(dppm)3]X and [X2Cu3(dppm)3](CuX2) and the novel neutral [(OCN)3Ag3(dpam)3]

Trinuclear cationic silver nanoclusters based-on bis-(phosphine) ligands and stabilized by CF3SO3− anions

Three trinuclear cationic silver nanoclusters based-on bis-(phosphine) ligands and stabilized by CF₃SO₃⁻ anions, displayed excellent photocurrent responses and electrochemical properties.

Using electrospray ionization-tandem mass spectrometry to explore formation and gas-phase chemistry of silver nanoclusters generated from the reaction of silver salts with NaBH4 in the presence of bis(diphenylarsino)methane

Electrospray ionization-mass spectrometry (ESI-MS) of mixtures of AgBF4 or AgNO3 with the capping ligand bis(diphenylarsino)methane ((Ph2 As)2 CH2 = dpam) in a solution of acetonitrile revealed the formation of the following cations: [Ag(CH3 CN)(dpam)]+ , [Ag(dpam)2 ]+ , [Ag2 (Cl)(dpam)2 ]+ , and [Ag3 (Cl)2 (dpam)3 ]+ . Addition of NaBH4 to these solutions results in the formation of the cluster cations [Ag2 (BH4 )(dpam)2 ]+ , [Ag2 (BH4 )(dpam)3 ]+ , [Ag3 (H)(BH4 )(dpam)3 ]+ , [Ag3 (BH4 )2 (dpam)3 ]+ , [Ag3 (H)(Cl)(dpam)3 ]+ , and [Ag3 (I)(BH4 )(dpam)3 ]+ , as established by ESI-MS. Use of NaBD4 confirmed that borohydride is the source of the hydride in these clusters. An Orbitrap Fusion LUMOS mass spectrometer was used to explore the gas-phase unimolecular chemistry of selected clusters via multistage mass spectrometry (MSn ) experiments employing low-energy collision-induced dissociation (CID) and high-energy collision-induced dissociation (HCD) experiments. The borohydride containing clusters fragment via two competing pathways: (i) ligand loss and (ii) B-H bond activation involving BH3 loss. Density functional theory (DFT) calculations were used to calculate the energetics of the optimized structures for all precursor ions, fragment ions, and neutrals and to estimate the reaction endothermicities. Generally, there is reasonable agreement between the most abundant product ion formed and the predicted endothermicity of the associated reaction channel. The DFT calculations predicted that the novel dimer [Ag2 (BH4 )(dpam)2 ]+ has a paddlewheel structure in which the dpam and BH4 - ligands bridge both silver centers.

Fifteen Years of Scientific Investigation into Main Groups and Transition Metal Coordination Chemistry with Allan White

The outcomes of the investigations on the structures and reactivity of a massive number of main group and transition metal complexes containing different families of ligands are reviewed. All the data result from the scientific collaboration between the research groups of Claudio Pettinari and Allan White which lasted fifteen years.

Alkyl Pyridinium Iodocuprate(I) Clusters: Structural Types and Charge Transfer Behavior

The reaction of copper(I) iodide (CuI) and N-alkyl pyridinium (RPy⁺, R = H, Me, Et, n-propyl = Pr, n-butyl = Bu, n-pentyl = Pn, and n-hexyl = Hx) or N-butyl-3-substituted pyridinium (N-Bu-3-PyX⁺, X = I, Br, Cl, CN, and OMe) iodide salts yielded pyridinium iodocuprate(I) salts. Crystal structures of iodocuprate ions coupled with RPy⁺ include {Cu₃I₆ ^3-} _n (R = H), {Cu₂I₃ ^-} _n (R = Me), {Cu₃I₄ ^-} _n (R = Et), {Cu₆I₈ ^2-} _n (R = Pr), and {Cu₅I₇ ^2-} _n (R = Bu, Pn, Hx). The [N-Bu-3-PyX]⁺ ions were typically paired with the 1-D chain {Cu₅I₇ ^2-} _n . Diffuse reflectance spectroscopy performed on the [N-Bu-3-PyX]⁺ iodocuprate salts revealed that increasing the electron withdrawing capacity of the [N-Bu-3-PyX]⁺ system reduced the absorption edge of the iodocuprate salt. Variable temperature emission spectra of several [N-Bu-3-PyX]⁺ compounds revealed two emission peaks, one consistent with a cluster-centered halide to metal charge transfer and the other consistent with an intermolecular mixed halide/metal charge transfer to the organic cation. The emission intensity and emission wavelength of the mixed halide/metal to cation charge transfer depends on the organic cation substitution.

The chelate-to-bridging shift of phosphane dipalladacycles: convenient synthesis of double A-frame tetranuclear complexes

Palladacycles of the type [Pd₂(Ph₂PCH₂PPh₂-P,P)₂(C,N:C,N)] (C,N:C,N = bis(N-2,3,4-trimethoxybenzylidene)-4,4'-sulfonyldianiline or -4,4'-oxydianiline) can undergo a spontaneous slow chelate-to-bridging diphosphane coordination shift in solution. Following this strategy a tailor-made synthetic procedure was devised that culminates in isolation of double A-frame tetranuclear palladium complexes.

Macrocycle-assisted synthesis of non-stoichiometric silver(i) halide electrocatalysts for efficient chlorine evolution reaction

The electrocatalytic oxidation of chloride to chlorine is a fundamental and important electrochemical reaction in industry. Herein we report the synthesis of non-stoichiometric silver halide nanoparticles through a novel macrocycle-assisted bulk-to-cluster-to-nano transformation. The acquired positively charged nanoparticles expedite chloride transportation by electrostatic attraction and facilitate the formation of silver polychloride catalytic species on the surface, thus functioning as efficient and selective electrocatalysts for the chlorine evolution reaction (CER) at a very low overpotential and within a wide concentration range of chloride. The formation of uncommon non-stoichiometric nanoparticles prevents the formation of a AgCl precipitate and exposes more coordination unsaturated silver atoms to catalyze CER, finally causing a large enhancement of the atomic catalytic efficiency of silver. This study showcases a promising approach to achieve efficient catalysts from a bottom-up design.

Crystal structure of tris-[μ2-bis-(di-phenyl-phosphan-yl)methane-κ(2) P:P']di-μ3-iodido-tris-ilver(I) iodide-N-phenyl-thio-urea (1/1)

The title complex, [Ag3I2(C25H22P2)3]I·C7H8N2S, comprises a trinuclear [Ag3I2(C25H22P2)3](+) unit, an I(-) anion and one N,N'-phenyl-thio-urea mol-ecule (ptu). Two μ3-bridging I(-) anions are linked by three Ag(I) ions, leading to the formation of a dicapped triangular motif with Ag⋯Ag separations in the range 3.0823 (5)-3.2999 (5) Å. Each Ag(I) atom exhibits a distorted tetra-hedral geometry, with coordination to two I atoms and two P atoms from bis-(di-phenyl-phosphan-yl)methane ligands. In the crystal, the I(-) anion is linked to the ptu mol-ecule through two N-H⋯I hydrogen bonds [graph-set motif R 2 (1)(6)]. These N-H⋯I hydrogen bonds, in addition to weak C-H⋯S and C-H⋯I hydrogen bonds, form zigzag chains along [010]. Two of the phenyl rings of two dppm ligands are disordered over two sets of sites with refined occupancies of 0.557 (16) and 0.443 (16).

Crystal structure of an unknown tetra-hydro-furan solvate of tetra-kis-(μ 3-cyanato-κ(3) N:N:N)tetra-kis-[(triphenyl-phosphane-κP)-silver(I)]

In the title compound, [{[(C6H5)3P]Ag}4{NCO}4], a distorted Ag4N4-heterocubane core is set up by four Ag(I) ions being coordinated by the N atoms of the cyanato anions in a μ 3-bridging mode. In addition, a tri-phenyl-phosphine ligand is datively bonded to each of the Ag(I) ions. Intra-molecular Ag⋯Ag distances as short as 3.133 (9) Å suggest the presence of argentophilic (d (10)⋯d (10)) inter-actions. Five moderate-to-weak C-H⋯O hydrogen-bonding inter-actions are observed in the crystal structure, spanning a three-dimensional network. A region of electron density was treated with the SQUEEZE procedure in PLATON [Spek (2015). Acta Cryst. C71, 9-18] following unsuccessful attempts to model it as being part of disordered tetra-hydro-furan solvent mol-ecules. The given chemical formula and other crystal data do not take into account these solvent mol-ecules.

Crystal structure of tris-[μ2-bis-(di-phenyl-phosphan-yl)methane-κ(2) P:P']di-μ3-bromido-tris-ilver(I) bromide-N,N'-phenyl-thio-urea (1/1)

The title complex, [Ag3Br2(C25H22P2)3]Br·C7H8N2S, comprises a trinuclear [Ag3Br2(C25H22P2)3](+) unit, a Br(-) anion and one N,N'-di-methyl-thio-urea mol-ecule (ptu). Three Ag(I) ions are linked via two μ3-bridging Br atoms, leading to a distorted triangular bipyramid with an Ag⋯Ag separation range of 3.1046 (6)-3.3556 (6) Å. The triangular Ag3 arrangement is stabilized by six P atoms from three chelating bis-(di-phenyl-phosphan-yl)methane (dppm) ligands. The Ag(I) ion presents a distorted tetra-hedral coordination geometry. In the crystal, the bromide anion is connected to the ptu mol-ecule through N-H⋯Br hydrogen bonds [graph-set motif R 2 (1)(6)]. Each bromide/ptu aggregate links the complex ion via C-H⋯S and C-H⋯Br hydrogen bonds, leading to the formation of a three-dimensional network. Two phenyl rings from two dppm ligands were modelled as disordered over two sites.

A novel visible light-driven silver isocyanate photocatalyst: superior stability enhanced by intrinsic resonance effect

A novel Ag-based visible-light photocatalyst, AgNCO, with superior stability employing intrinsic resonance effect.

Mono, bi- and trinuclear metal complexes derived from new benzene-1,4-bis(3-pyridin-2-ylurea) ligand. Spectral, magnetic, thermal and 3D molecular modeling studies

New bis (pyridylurea) ligand, H2L, was synthesized by the reaction of ethylpyridine-2-carbamate (EPC) and p-phenylenediamine. The ligand was characterized by elemental analysis, IR, (1)H NMR, electronic and mass spectra. Reaction of the prepared ligand with Co(2+), Ni(2+), Cu(2+), Fe(3+), VO(2+) and UO2(2+) ions afforded mono, bi- and trinuclear metal complexes. Also, new mixed ligand complexes of the ligand H2L and 8-hydroxyquinoline (8-HQ) with Co(2+), Ni(2+), Cu(2+) and Fe(3+) ions were synthesized. The ligand behaves as bi- and tetradentate toward the transition metal ions, coordination via the pyridine N, the carbonyl O and/or the amidic N atoms in a non, mono- and bis-deprotonated form. The complexes were characterized by elemental and thermal analyses, IR, electronic and mass spectra as well as conductance and magnetic susceptibility measurements. The results showed that the metal complexes exhibited different geometrical arrangements such as square planar, tetrahedral, octahedral and square pyramidal arrangements. The Coats-Redfern equation was used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition steps of some complexes. 3D molecular modeling of the ligand, H2L and a representative complex were studied.

A two-dimensional silver–iodide organic network constructed from a unique [Ag6I6] hexagonal prism-based one-dimensional column motif

A novel two-dimensional coordination polymer, poly[[μ2-1,3-bis(2-methyl-1H-imidazol-1-yl)propane]di-μ4-iodido-di-μ3-iodido-silver(I)], [Ag4I4(C11H16N4)]n, (I), has been synthesized by solvothermal reaction of AgNO3, KI and 1,3-bis(2-methyl-1H-imidazol-1-yl)propane (bmimp). In (I), the two unique AgIcations have AgNI3and AgI4four-coordinated tetrahedral geometries. The bmimp ligand has imposed twofold symmetry. The AgIcations and iodide anions form a unique one-dimensional polymeric column motif incorporating [Ag6I6] hexagonal prisms, which are then connected by bmimp ligands to form two-dimensional organic–inorganic layers. The layers are arranged in parallel in anABABfashion and are packed into the resultant three-dimensional supramolecular framework by van der Waals interactions.