AgI Atom Research Articles

Bis[2,3-bis-(thio-phen-2-yl)pyrido[3,4-b]pyrazine]-silver(I) perchlorate methanol disolvate.

The title compound, [Ag(C15H9N3S2)2]ClO4·2CH3OH, is monoclinic. The AgI atom is coordinated by pyrido N atoms and is two-coordinate; however, the AgI atom has nearby O atoms that can be assumed to be weakly bonded - one from the perchlorate anion and one from the methanol solvate molecule. One of the thienyl groups on a 2,3-bis-(thio-phen-2-yl)pyrido[3,4-b]pyrazine is flipped disordered and was refined to occupancies of 68.4 (6) and 31.6 (6)%.

(Nitrito-κ2 O,O')bis-[tris-(4-methyl-phen-yl)phosphane-κP]silver(I).

The mol-ecular structure of the title compound, [Ag(NO2)(C21H21P)2], exhibits a pseudo-tetra-hedral coordination around the central AgI atom. The compound crystallizes with one mol-ecule in the asymmetric unit in the monoclinic space group P21/n with a rather long b axis [33.8752 (2) Å]. Weak C-H⋯O and C-H⋯N inter-actions consolidate the crystal packing. The nitrite-O atoms each occupy a single position in the coordination geometry.

Tris(benzyl-diphenyl-phosphane-κP)(nitrato-κO)silver(I).

The mol-ecular structure of the title complex, [Ag(NO3)(C19H17P)3], exhibits a severely distorted tetra-hedral coordination environment around the central AgI atom, comprising one O and three P atoms. Apart from a primary Ag-O coordination of the nitrato ligand of 2.667 (3) Å, a second (weaker) secondary inter-action of the nitrato ligand via the other O atom of 3.118 (4) Å is observed. The compound crystallizes with a complete mol-ecule in the asymmetric unit. Weak C-H⋯O inter-actions consolidate the packing.

Bis[(4-methylphenyl)diphenylphosphane-κP](nitrato-κ2 O,O′)silver(I)

The molecular structure of the title AgI complex, [Ag(NO3)(C19H17P)2] or [Ag{(p-CH3C6H4)(C6H5)2P-κP}2-NO3-κ2 O:O′], is described, where a distorted trigonal–planar coordination environment is exhibited about the central AgI atom; in this description, the two O atoms are assumed to occupy one position in the coordination sphere. The compound crystallized with half a molecule in the asymmetric unit having the AgI atom lying on a twofold axis.

Bis[(4-methyl-phen-yl)di-phenyl-phosphine-κP](nitrito-κ2 O,O')silver(I).

The title AgI complex, [Ag(NO2)(C19H17P)2], reveals a distorted pseudo-trigonal-planar shape around the AgI atom geometry resulting from the coordination of two phosphine ligands, as well as a nitrito-O,O' ligand coordinating to the silver(I) atom through the oxygen atoms; in this description, the two oxygen atoms are assumed to occupy one position, forming an acute O-Ag-O angle of 51.44 (9)°. The plane resulting from the NO2 coordination to Ag is nearly perpendicular to the plane from the coordination of the phosphine-P atoms to Ag [dihedral angle = 86.43 (9)°].

Bis(isonicotinamide-κN)silver(I) tri-fluoro-methane-sulfonate aceto-nitrile disolvate.

The central AgI atom of the title salt, [Ag(INAM)2](CF3SO3)·2CH3CN, where INAM is isonicotinamide (C6H6N2O), is twofold coordinated by the pyridine N atoms of two isonicotinamide ligands creating a slightly distorted linear mol-ecular geometry. The formation of polymeric chains {[Ag(INAM)2]+} n , held together by discrete hydrogen bonds through the amide group of the INAM ligand leaves voids for non-coordinating aceto-nitrile mol-ecules that inter-act the silver metal center via regium bonds.

Chemical design of heterometallic carboxylate structures with Fe3+ and Ag+ ions as a rational synthetic approach

Solid phase thermolysis of pivalate complex [Fe3O(Piv)6(HPiv)3]Piv generates the [Fe3O(Piv)6]+ complex cation due to a deficiency of ligands in the coordination sphere of the metal ions. Crystallization of [Fe3O(Piv)6]+ from THF–EtOH leads to the heteroleptic complex [Fe3O(Piv)6(THF)(EtOH)(OH)] · 0.5 THF · 0.5 H2O in 69% yield, while the reaction of [Fe3O(Piv)6]+ with AgNO3 in toluene results in the complex [Fe4Ag4O2(Piv)12] · 2 PhMe with a rare combination of FeIII and AgI atoms. Crystal structures of the two new complexes have been established.

Precise Implantation of an Archimedean Ag@Cu12 Cuboctahedron into a Platonic Cu4Bis(diphenylphosphino)hexane6 Tetrahedron.

Precision loading of nanoclusters in confined spaces, which has been enthusiastically pursued in the scientific realm, is still associated with some mysteries of "how", "when", and "why". Here, we isolated two similar heterometallic cluster-in-cage compounds, [Ag@Cu12S8@Cu4(dpph)6]X (X = OH, SD/AgCu16a and X = PF6, SD/AgCu16b; SD = SunDi), by use of an antigalvanic reaction between organometallic [PhC≡CCu]n and Ph3CSH with elemental silver. Both compounds are formed by fitting an Archimedean Ag@Cu12 cuboctahedral cluster into a Platonic Cu4(dpph)6 tetrahedral cage [dpph = bis(diphenylphosphino)hexane]. The Ag@Cu12 cluster is a hollow cuboctahedral Cu12 cage filled with a central AgI atom, and all eight triangular faces of the Ag@Cu12 cuboctahedron are triply capped by eight S2- ions, four of which in a tetrahedral array further internally pillar four Cu vertices of the outer Cu4(dpph)6 tetrahedron, fixing the cluster in the cage. Both compounds can be deemed as molecular fragments excised from porous nanomaterials filled with discrete nanoclusters, thus providing more details for understanding the confined growth of atomically precise nanoclusters. Electrospray ionization mass spectrometry (ESI-MS) reveals that the AgCu16 cluster is quite stable in CH2Cl2 and can stepwise lose dpph ligand in the gas phase under increased collision energy. This work not only presents a precise aggregation of metal atoms in a confined cavity to form a cluster-in-cage compound but also provides deep insights into the binding and geometry matching between clusters and cages in one entity.

Insertion of a Hydride Ion Into a Tetrasilver(I) Cluster Covered by S-Donating Rhodium(III) Metalloligands.

Here, we report a tetrahedral silver(I) cluster of {Ag4}4+ covered by Δ-[Rh(l-cys)3]3- (l-H2cys = l-cysteine), which is converted to an {Ag4H}3+ cluster via the inclusion of a H- ion. The 1:1 reaction of Δ-[Rh(l-cys)3]3- with Ag+ gave a sulfur-bridged AgI4RhIII4 octanuclear structure in [Ag4{Rh(l-cys)3}4]8- ([1]8-), in which a tetrahedral {Ag4}4+ core is bound by four Δ-[Rh(l-cys)3]3- units through thiolato groups. DFT calculations revealed that a superatomic orbital exists in {Ag4}4+ as the lowest unoccupied molecular orbital, contributing to the appearance of a characteristic charge-transfer transition in the visible region for [1]8-. Treatment of [1]8- with NaBH4 led to the insertion of a H- ion to generate [Ag4H{Rh(l-cys)3}4]9- ([2]9-) with an {Ag4H}3+ core, accompanied by the disappearance of the visible band for [1]8-. The presence of a H- ion in the center of [2]9- was established by the 1H NMR spectrum, which reveals a unique quintuple-quintet signal from the H- ion surrounded by four AgI atoms. [2]9- was considerably stable in aqueous media, which is ascribed to a chemical bond between the unoccupied superatomic orbital of {Ag4}4+ and the occupied orbital of H- in the {Ag4H}3+ core.

Crystal and mol-ecular structures of a binuclear mixed ligand complex of silver(I) with thio-cyanate and 1H-1,2,4-triazole-5(4H)-thione.

The complete mol-ecule of the binuclear title complex, bis-[μ-1H-1,2,4-triazole-5(4H)-thione-κ2 S:S]bis-{(thio-cyanato-κS)[1H-1,2,4-triazole-5(4H)-thione-κS]silver(I)}, [Ag2(SCN)2(C2H3N3S)4], is generated by crystallographic inversion symmetry. The independent triazole-3-thione ligands employ the exocyclic-S atoms exclusively in coordination. One acts as a terminal S-ligand and the other in a bidentate (μ2) bridging mode to provide a link between two AgI centres. Each AgI atom is also coordinated by a terminal S-bound thio-cyanate ligand, resulting in a distorted AgS4 tetra-hedral coordination geometry. An intra-molecular N-H⋯S(thio-cyanate) hydrogen bond is noted. In the crystal, amine-N-H⋯S(thione), N-H⋯N(triazol-yl) and N-H⋯N(thio-cyanate) hydrogen bonds give rise to a three-dimensional architecture. The packing is consolidated by triazolyl-C-H⋯S(thio-cyanate), triazolyl-C-H⋯N(thiocyanate) and S⋯S [3.2463 (9) Å] inter-actions as well as face-to-face π-π stacking between the independent triazolyl rings [inter-centroid separation = 3.4444 (15) Å]. An analysis of the calculated Hirshfeld surfaces shows the three major contributors are due to N⋯H/H⋯N, S⋯H/H⋯S and C⋯H/H⋯C contacts, at 35.8, 19.4 and 12.7%, respectively; H⋯H contacts contribute only 7.6% to the overall surface.

Three AgI, CuI and CdII coordination polymers based on the new asymmetrical ligand 2-{4-[(1H-imidazol-1-yl)methyl]phenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazole: syntheses, characterization and emission properties.

The new asymmetrical organic ligand 2-{4-[(1H-imidazol-1-yl)methyl]phenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazole (L, C17H13N5O), containing pyridine and imidazole terminal groups, as well as potential oxdiazole coordination sites, was designed and synthesized. The coordination chemistry of L with soft AgI, CuI and CdII metal ions was investigated and three new coordination polymers (CPs), namely, catena-poly[[silver(I)-μ-2-{4-[(1H-imidazol-1-yl)methyl]phenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazole] hexafluoridophosphate], {[Ag(L)]PF6}n, catena-poly[[copper(I)-di-μ-iodido-copper(I)-bis(μ-2-{4-[(1H-imidazol-1-yl)methyl]phenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazole)] 1,4-dioxane monosolvate], {[Cu2I2(L)2]·C4H8O2}n, and catena-poly[[[dinitratocopper(II)]-bis(μ-2-{4-[(1H-imidazol-1-yl)methyl]phenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazole)]-methanol-water (1/1/0.65)], {[Cd(L)2(NO3)2]·2CH4O·0.65H2O}n, were obtained. The experimental results show that ligand L coordinates easily with linear AgI, tetrahedral CuI and octahedral CdII metal atoms to form one-dimensional polymeric structures. The intermediate oxadiazole ring does not participate in the coordination interactions with the metal ions. In all three CPs, weak π-π interactions between the nearly coplanar pyridine, oxadiazole and benzene rings play an important role in the packing of the polymeric chains.

Crystal structure of tetra-kis-[μ-3-carboxy-1-(1,2,4-triazol-4-yl)adamantane-κ2 N 1:N 2]tetra-fluoridodi-μ2-oxido-dioxidodisilver(I)divanadium(V) tetra-hydrate.

The crystal structure of the title mol-ecular complex, [Ag2{VO2F2}2(C13H17N3O2)4]·4H2O, supported by the heterofunctional ligand tr-ad-COOH [1-(1,2,4-triazol-4-yl)-3-carb-oxy-adamantane] is reported. Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI 2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal-bipyramidal coordination environment [VO2F2N]. A carb-oxy-lic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water mol-ecules and VO2F2 - ions of adjacent mol-ecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.

Sonochemical synthesis of highly luminescent silver complexes: Photophysical properties and preliminary in vitro antitumor and antibacterial assays

Novel mononuclear silver(I) complexes based on thiocarbamoyl-pyrazoline ligands were synthesized and structurally characterized. Complexes 1 and 2 were prepared in good yields using a sonochemical method. X-ray diffraction studies revealed trigonal coordination geometry for the AgI atom in complex 1 and distorted trigonal pyramidal geometry in complex 2, according to τ4 parameter analysis. Investigation of photophysical properties revealed intense blue-greenish emissions both in solution and in the solid state when excited at 300 nm. This emission was tentatively attributed to mixed (M+X)LCT and IL electronic transitions taking place after ligand metalation, as shown by DFT calculations. Complete characterization of the prepared compounds was also performed, including 1H and 13C NMR experiments, elemental analysis, infrared spectroscopy, absorption/emission studies, and time-resolved luminescence experiments. The synthesized ligands and complexes 1 and 2 were also tested as antibacterial agents against two standard bacterial strains (Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922) and a panel of clinical S. aureus strains with distinct antibiotic-resistance profiles. Antitumor activity was investigated against melanoma cells (B16F10) and mammary carcinoma cells (4T1).

Silver(I)‐Based Complexes Used as High‐Performance Photocatalysts for the Degradation of Organic Dyes in Water

Coordination compounds have been used as efficient photocatalysts for the degradation of pollutive organic dyes due to their semiconductive nature and diverse structures that may be adjusted by the central metals and ligands. Herein we prepared N′,N′‐2,2‐tetrakis(diphenylphosphanylmethyl)thiocarbohydrazide (tpptch) and utilized it to react with AgX (X = Br, I, CN) in different solvent systems. These reactions afforded two dicationic tetranuclear complexes {[Ag4X2(tpptch)2]X2 (1: X = Br; 2: X = I)}, one 1D coordination polymer [Ag2I2(tpptch)]n (3) and one neutral tetranuclear complex [Ag4(CN)2(dptpptch)2] (4, dptpptch is the anion of deprotonated tpptch after an enolization). In 1–4, the S atom of the C=S group binds at one AgI atom in 1 or 2, or remains uncoordinated in 3, or connects with two AgI atoms after transforming into the C–S– end in 4. The catalytic activities of these compounds toward the photodegradation of nine organic dyes under UV irradiation were examined, among which 3 showed the best performance. Their anodic photocurrent responses and HOMO–LUMO energy gaps derived from density functional theory (DFT) calculations correlated well with the photocatalytic activities. The different bindings of the S end of tpptch and dptpptch ligands with AgI centers in 2–4 may be contributed to the discrepancy in their catalytic activities. The results provide a ready route to design and prepare highly stable and efficient photocatalysts for treating dye‐polluted water.

Matrix Coordination Induced Emission in a Three-Dimensional Silver Cluster-Assembled Material.

Developing highly luminescent and extensively stable silver cluster-assembled materials (SCAMs) from the inferior luminogens and unstable silver cluster is an important and challenging issue. Herein, a new luminescent three-dimensional SCAM (Ag12 CPPP, [Ag12 (StBu)6 (CF3 COO)6 (CPPP)2 (DMAc)12 ]n ; CPPP=2,5-bis(4-cyanophenyl)-1,4-bis(4-(pyridine-4-yl)-phenyl)-1,4-dihydropyrrolo[3,2-b]pyrrole, DMAc=dimethylacetamide) was designed and synthesized with a quadridentate rigid emission ligand (CPPP) and a silver-chalcogenolate cluster (SCC) containing 12 AgI atoms. The luminescence study indicates that CPPP is an aggregation-caused quenching (ACQ) molecule with twisted intramolecular charge transfer (TICT) character. Benefiting from the strong immobilization effect in the robust framework, the quantum yield of CPPP is greatly enhanced in Ag12 CPPP compared with that of CPPP in solution or in the solid state. As a result, Ag12 CPPP exhibits typical matrix coordination induced emission (MCIE) effect. Such efficient rigidifying methodology provides a promising approach for enhancing luminescence of ACQ molecules in an aggregated state and strengthening the silver cluster in an unstable state.

First heterobimetallic AgI-CoIII coordination compound with both bridging and terminal -NO2 coordination modes: synthesis, characterization, structural and computational studies of (PPh3)2AgI-(μ-κ2O,O':κN-NO2)-CoIII(DMGH)2(κN-NO2).

An unusual heterobimetallic bis(triphenylphosphane)(NO2)AgI-CoIII(dimethylglyoximate)(NO2) coordination compound with both bridging and terminal -NO2 (nitro) coordination modes has been isolated and characterized from the reaction of [CoCl(DMGH)2(PPh3)] (DMGH2 is dimethylglyoxime or N,N'-dihydroxybutane-2,3-diimine) with excess AgNO2. In the title compound, namely bis(dimethylglyoximato-1κ2O,O')(μ-nitro-1κN:2κ2O,O')(nitro-1κN)bis(triphenylphosphane-2κP)cobalt(III)silver(I), [AgCo(C4H7N2O2)2(NO2)2(C18H15P)2], one of the ambidentate -NO2 ligands, in a bridging mode, chelates the AgI atom in an isobidentate κ2O,O'-manner and its N atom is coordinated to the CoIII atom. The other -NO2 ligand is terminally κN-coordinated to the CoIII atom. The structure has been fully characterized by X-ray crystallography and spectroscopic methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been used to study the ground-state electronic structure and elucidate the origin of the electronic transitions, respectively.

Ab initio study of ionic nature of 0.75AgI:0.25AgCl

Ab initio calculations based on density functional theory are performed for zinc-blende structured new host 0.75AgI:0.25AgCl. Eight configurations are simulated for different positions of Cl atoms, and they are divided into three sets of configurations. Similar calculations are also performed for zinc blende β-AgI. Bond lengths are changed and p-d hybridization is observed in all configurations. Ionic nature of atomic bonds is analyzed by the ionicity factor. The charge density analysis also exhibits the ionic and least covalent nature of bonds of AgI and AgCl atoms. The structural parameters are calculated to observe the bulk modulus. Crystal orbital overlap population analysis explains the inter-atomic bond strength which explains the bond breaking energy and activation energy of all configurations.

Chemical Origin of the Stability Difference between Copper(I)‐ and Silver(I)‐Based Halide Double Perovskites

AbstractRecently, CuI‐ and AgI‐based halide double perovskites have been proposed as promising candidates for overcoming the toxicity and instability issues inherent within the emerging Pb‐based halide perovskite absorbers. However, up to date, only AgI‐based halide double perovskites have been experimentally synthesized; there are no reports on successful synthesis of CuI‐based analogues. Here we show that, owing to the much higher energy level for the Cu 3d10 orbitals than for the Ag 4d10 orbitals, CuI atoms energetically favor 4‐fold coordination, forming [CuX4] tetrahedra (X=halogen), but not 6‐fold coordination as required for [CuX6] octahedra. In contrast, AgI atoms can have both 6‐ and 4‐fold coordinations. Our density functional theory calculations reveal that the synthesis of CuI halide double perovskites may instead lead to non‐perovskites containing [CuX4] tetrahedra, as confirmed by our material synthesis efforts.

Chemical Origin of the Stability Difference between Copper(I)- and Silver(I)-Based Halide Double Perovskites.

Recently, CuI - and AgI -based halide double perovskites have been proposed as promising candidates for overcoming the toxicity and instability issues inherent within the emerging Pb-based halide perovskite absorbers. However, up to date, only AgI -based halide double perovskites have been experimentally synthesized; there are no reports on successful synthesis of CuI -based analogues. Here we show that, owing to the much higher energy level for the Cu 3d10 orbitals than for the Ag 4d10 orbitals, CuI atoms energetically favor 4-fold coordination, forming [CuX4 ] tetrahedra (X=halogen), but not 6-fold coordination as required for [CuX6 ] octahedra. In contrast, AgI atoms can have both 6- and 4-fold coordinations. Our density functional theory calculations reveal that the synthesis of CuI halide double perovskites may instead lead to non-perovskites containing [CuX4 ] tetrahedra, as confirmed by our material synthesis efforts.

A one-dimensional silver(I) coordination polymer based on 5-methyl-1,3,4-thiadiazol-2-amine and pyridine-2,3-dicarboxylate.

The bifunctional pyridine-2,3-dicarboxylic acid (H2pdc) ligand has one N atom and four O atoms, which could bind more than one AgI centre with diverse binding modes. A novel infinite one-dimensional AgI coordination polymer, namely catena-poly[[silver(I)-(μ2-pyridine-2,3-dicarboxylato-κ2N:O3)-silver(I)-tris(μ2-5-methyl-1,3,4-thiodiazol-2-amine-κ2N:N')] monohydrate ethanol monosolvate], {[Ag2(C7H3NO4)(C3H5N3S)3]·H2O·C2H5OH}n, has been synthesized using H2pdc and 5-methyl-1,3,4-thiadiazol-2-amine (tda), and characterized by single-crystal X-ray diffraction. One AgI atom is located in a four-coordinated AgN4 tetrahedral geometry and the other AgI atom is in a tetrahedral AgN3O geometry. A dinuclear AgI cluster formed by three tda ligands with a paddelwheel configuration is bridged by the dianionic pdc2- ligand into a one-dimensional coordination polymer. Interchain N-H...O hydrogen bonds extend the one-dimensional chains into an undulating two-dimensional sheet. The sheets are further packed into a three-dimensional supramolecular framework by interchain N-H...O hydrogen bonds.