New silver(I) coordination polymers constructed from pyrazine derivatives and aromatic carboxylic acids: Syntheses, structures and photoluminescence

Diantimony Complexes [CpR 2 Mo2 (CO)4 (μ,η2 -Sb2 )] (CpR =C5 H5 , C5 H4 t Bu) as Unexpected Ligands Stabilizing Silver(I)n (n=1-4) Monomers, Dimers and Chains

Synthesis and reactivity of transition metal compounds bearing "naked" pnictogen atoms is an active research area with remarkable bonding patterns observed in the formed compounds. Within this field, intense investigations on the coordination behavior of complexes possessing Pn and Asn (2≤n≤5) moieties have been conducted. However, studies on heavier analogues have been ignored so far due to arduous challenges related to low yields and moderate air stability. Herein, we present the first in-depth study addressing the reactivity of organometallic complexes containing Sb-donor atoms with several AgI salts. These reactions afforded twelve unprecedented aggregates as monomers, dimers as well as three- and four-membered chains of AgI ions claimed in the literature to be inaccessible. Interatomic distances as well as computational evidence obtained with help of several different methods suggest the presence of Ag⋅⋅⋅Ag interactions in all complexes containing more than one AgI ion.

Mixed Organometallic-Organic Hybrid Assemblies Based on the Diarsene Complex [Cp2 Mo2 (CO)4 (μ,η2 -As2 )], AgI Salts and N-Donor Organic Molecules

The reaction of the organometallic diarsene complex [Cp2 Mo2 (CO)4 (η2 -As2 )] (1) with Ag[Al{OC(CF3 )3 }4 ] (Ag[TEF]) yielded the AgI monomer [Ag(η2 -1)3 ][TEF] (2). This compound exhibits dynamic behavior in solution, which allows directed selective synthesis of unprecedented organometallic-organic hybrid assemblies upon its reaction with N-donor organic molecules by a stepwise pathway, which is supported by DFT calculations. Accordingly, the reaction of 2 with 2,2'-bipyrimidine (L1) yielded the dicationic molecular compound [{(η2 -1)2 Ag}2 (μ-L1)][TEF]2 (3) or the 1D polymer [{(η2 -1)Ag}(μ-L1)]n [TEF]n (4) depending on the ratio of the reactants. However, its reactions with the pyridine-based linkers 4,4'-bipyridine (L2), 1,2-bis(4-pyridyl)ethylene (L3) and 1,2-bis(4-pyridyl)ethyne (L4) allowed the formation of the 2D polymers [{(η2 -1)Ag}2 (μ-Lx)3 ]n [TEF]2n [Lx=L2 (5), L3 (6), L4 (7), respectively]. Additionally, this concept was extended to step-by-step one-pot reactions of 1, [Ag(CH3 CN)3 ][Al{OC(CF3 )2 (CCl3 )}4 ] ([Ag(CH3 CN)3 ][TEFCl ]) and linkers L2-L4 to produce the 2D polymers [{(η2 -1)Ag}2 (μ,Lx)3 ]n [TEFCl ]2n [Lx=L2 (8), L3 (9), L4 (10), respectively].

The Potential of the Diarsene Complex [(C5 H5 )2 Mo2 (CO)4 (μ,η2 -As2 )] as a Connector Between Silver Ions

The reaction of the organometallic diarsene complex [Cp₂Mo₂(CO)₄(μ,η²‐As₂)] (B) (Cp = C₅H₅) with Ag[FAl{OC₆F₁₀(C₆F₅)}₃] (Ag[FAl]) and Ag[Al{OC(CF₃)₃}₄] (Ag[TEF]), respectively, yields three unprecedented supramolecular assemblies [(η²‐B)₄Ag₂][FAl]₂ (4), [(μ,η¹:η²‐B)₃(η²‐B)₂Ag₃][TEF]₃ (5) and [(μ,η¹:η²‐B)₄Ag₃][TEF]₃ (6). These products are only composed of the complexes B and Ag^I. Moreover, compounds 5 and 6 are the only supramolecular assemblies featuring B as a linking unit, and the first examples of [Ag^I]₃ units stabilized by organometallic bichelating ligands. According to DFT calculations, complex B coordinates to metal centers through both the As lone pair and the As−As σ‐bond thus showing this unique feature of this diarsene ligand.

A new antibacterial silver(I) complex incorporating 2,5-dimethylpyrazine and the anti-inflammatory diclofenac

Ag^I-containing coordination complexes have attracted attention because of their photoluminescence properties and antimicrobial activities and, in principle, these properties depend on the nature of the structural topologies. A novel two-dimensional silver(I) complex with the anti-inflammatory diclofenac molecule, namely bis{μ-2-[2-(2,6-dichloroanilino)phenyl]acetato-κ³O,O':O}bis(μ-2,5-dimethylpyrazine-κ²N:N')silver(I), [Ag₂(C₁₄H₁₀Cl₂NO₂)₂(C₆H₈N₂)]_n, (I), has been synthesized and characterized by single-crystal X-ray diffraction, revealing that the Ag^I ions are chelated by the carboxylate groups of the anionic 2-[2-(2,6-dichloroanilino)phenyl]acetate (dicl) ligand in a μ₃-η¹:η² coordination mode. Each dicl ligand links three Ag^I atoms to generate a one-dimensional infinite chain. Adjacent chains are connected through 2,5-dimethylpyrazine (dmpyz) ligands to form a two-dimensional layer structure parallel to the crystallographic bc plane. The layers are further connected by C-H...π interactions to generate a three-dimensional supramolecular structure. Additionally, the most striking feature is that the structure contains an intramolecular C-H ...Ag anagostic interaction. Furthermore, the title complex has been tested for its in vitro antibacterial activity and is determined to be highly effective on the studied microorganisms.

Crystal structure of a mixed-ligand silver(I) complex of the non-steroidal anti-inflammatory drug diclofenac and pyrimidine

In the title mixed-ligand silver(I) coordination polymeric complex with the non-steroidal anti-inflammatory drug diclofenac (C14H11Cl2NO2) (diclH) and pyrimidine (pym), namely poly[{μ2-2-[2-(2,6-di-chloro-anilino)phen-yl]acetato-κ2O:O'}(μ2-pyrimidine-κ2N1:N3)silver(I)], [Ag(C14H10Cl2NO2)(C4H4N2)] n or [Ag(μ-dicl)(μ-pym)] n , the very distorted tetra-hedral AgN2O2 coordination centres comprise two N-atom donors from bridging pym ligands [Ag-N = 2.381 (3) and 2.412 (3) Å] and two carboxyl-ate O-atom donors from dicl ligands [Ag-O = 2.279 (2) and 2.280 (2) Å], which bridge Ag atoms, giving a centrosymmetric dinuclear units with a short Ag⋯Ag separation [2.8931 (5) Å]. Within the units are short intra-ligand C-Cl⋯π(pym) inter-actions [3.6409 (15) Å]. The units are linked through the bridging N atoms of the pym ligand into a two-dimensional sheet-polymer structure lying parallel to (100) and stabilized by inter-ring π-π inter-actions between the pym ligands [Cg⋯Cg = 3.4199 (17) Å]. Additional inter-unit C-H⋯O and C-H⋯Cg hydrogen-bonding inter-actions between the sheets give an overall three-dimensional structure.