AgX Salts Research Articles

Controlling the Size of Molecular Copper Clusters Supported by a Multinucleating Macrocycle.

The use of a nonrigid, pyridyldialdimine-derived macrocyclic ligand (3PDAI2) enabled the synthesis of well-defined mono-, di-, tri-, and tetra-nuclear Cu(I) complexes in good yields through rational synthetic means. Starting from mono- and diargentous 3PDAI2 complexes, transmetalation to Cu(I) proceeded smoothly with formation of AgX (X = Cl, I) salts to generate mono-, di-, and trinuclear copper complexes. Monodentate supporting ligands (MeCN, xylNC, PMe3, PPh3) were found to either transmetallate with or bind various di- and trinuclear clusters. The solution-phase dynamic behaviors of these species were studied through NMR spectroscopic investigations, and an in-depth study of the trinuclear systems revealed a rate dependence on the identity of the supporting ligand, indicating that ligand dissociation reactions were involved in the dynamic exchange processes. Synthetic investigations further found methods for the purposeful interconversion between the di- and trinuclear systems as well as the synthesis of a pseudotetrahedral tetracopper complex with two μ-Ph supporting ligands.

Increasing enantioselectivity and reactivity in Ir-Catalysed intramolecular hydroamination reactions

A series of axially chiral NHC ligands bearing dialkylated naphthyl side arms and electron-rich substituted phenyl groups in the backbone have been employed in the synthesis of neutral NHC-Ir(COD)Cl complexes. When the halide ligand was abstracted from these compounds by appropriate silver salts AgX (X = PF6, NTf2), chiral cationic, formally 14-electron iridium complexes [(NHC)Ir(COD)][X] were formed. When these species were applied as catalysts for asymmetric intramolecular hydroamination of unactivated, amino-olefin substrates, chiral 5- and 6- membered N-heterocyclic products were obtained with moderate to excellent enantioselectivities. By tuning the substrate through variation of the N-protecting group on the amino-olefin substrates, remarkable improvements in enantioselectivity were obtained.

N-Coordinated tellurenium(II) and telluronium(IV) cations: synthesis, structure and hydrolysis.

A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RNCH)C6H4, R = tBu or Dipp; Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RNCH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann-Beckett method using Et3PO as the probing agent. The Te-N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators.

Ag(I)‐mediated hydrolysis of hydrazone to azine: Synthesis, X‐ray structure, and biological investigations of two new Ag(I)‐azine complexes

AbstractReactions of 2‐(1‐hydrazonoethyl)pyridine with silver salts AgX (X = NO3¯ or ClO4¯) proceeded via the hydrolysis of the pyridine ligand and the formation of the dinuclear [AgL1]2(ClO4)2 (1) and [AgL1(NO3)]2 (2) complexes of the azine ligand, 1,2‐bis(1‐(pyridin‐2‐yl)ethylidene)hydrazine (L1). The structures of the obtained complexes were determined by single crystal X‐ray diffraction. The azine ligand (L1) is acting as a bidentate ligand and connects the two Ag‐sites via the pyridine and the azine nitrogen atoms. In complex 1, the Ag(I) ion is tetra‐coordinated, while in complex 2 the Ag(I) ion is penta‐coordinated due to the presence of additional interaction with one of the oxygen atoms of the nitrate ion. As a result, the azine ligand is significantly twisted in complex 2 compared to complex 1. The optimized geometries of three conformers of L1 were calculated using DFT calculations, and their kinetic and thermodynamic stability were analyzed. It was found that a free rotation of L1 is required prior to the chelation of the Ag(I) ion. The packing in complex 1 is controlled by H…H, O…H, and Ag…O interactions, but in complex 2, the O…H and N…H interactions are the most significant. Complex 2 has better antifungal activity against Aspergillus fumigatus and Candida albicans than the antifungal drug Ketoconazole. Also, the nitrato complex 2 has a promising antioxidant activity compared to the perchlorate complex 1. The cytotoxicity against colon carcinoma HCT‐116 cell line is higher for complex 1 (IC50 = 19.72 ± 0.94 μg/ml) than complex 2 (IC50 = 68.31 ± 2.97 μg/ml).

Water-soluble Ag(I)-based coordination polymers obtained by anion-directed self-assembly of various AgX salts and a phosphabetaine derived from 1,3,5-triaza-7-phophaadamantane

A new, solvent-free method has been developed for the synthesis of 7-(2-carboxy-ethyl)-1,3,5-triaza-7-(phosphoniatricyclo)[3.3.1.13,7]decane (L). It is disclosed here that 1,3,5-triaza-7-phosphaadamantane (PTA) reacted cleanly with acrylic acid in a planetary ball mill resulting in 88% yield of the corresponding P-carboxy-ethyl derivative, in striking contrast to the complete failure of the synthesis of the same product from the same reactants in solution. The resulting phosphabetaine, L gave crystalline 1D coordination polymers with Ag+-salts bearing PF6-, p-toluenesulfonate (tos) and trifluoromethanesulfonate (OTf) anions. According to single-crystal X-ray diffraction studies, the solid state structures of these coordination polymers were decisively influenced by the anion of the Ag+-salt used for synthesis. In addition to single-crystal X-ray diffraction, the new Ag-based coordination polymers, namely [Ag(μ3-L-κ3N:O:O’)]n(PF6)n, (1), [Ag(tos)(μ3-L-κ3N:N:O)]n·nH2O, (2), and [Ag(OTf)(μ3-L-κ3N:O:O’)]n, (3) were characterized also by elemental analysis, 1H-, 13C-, and 31P NMR, as well as IR spectroscopies and with ESI mass spectrometry. Determination of the hydrodynamic diameter of the phosphabetaine ligand and its Ag+-complexes by diffusion NMR measurements revealed, that upon dissolution in water these compounds did not retain their polymeric nature.

Construction and anion exchange of silver(I) complexes bearing 1,2,3-tris(isonicotinoyloxy)benzene

A new potentially tridentate ligand 1,2,3-tris(isonicotinoyloxy)benzene (L) was prepared, and its coordination chemistry with various silver(I) salts AgX (X− = BF4−, ClO4−, PF6−, and CF3SO3−) was investigated in order to elucidate the effects of counteranion size. Self-assembly of silver(I) salts with L afforded four complexes with 1:1 stoichiometries. The molecular structures with small counteranions (BF4−, ClO4−, and PF6−) showed 2-D networks whereas those with large counteranions (CF3SO3−) showed a 1-D network. These silver(I) compounds were fully characterized by infrared spectroscopy, elemental and thermal analyses, and single crystal X-ray diffraction. The role of the present counteranions in determining the structural motifs is discussed in these pages.

Highly Emissive Cycloplatinated(II) Complexes Obtained by the Chloride Abstraction from the Complex [Pt(ppy)(PPh3)(Cl)]: Employing Various Silver Salts

In the present investigation, the precursor complex [Pt(ppy)(PPh3)(Cl)], 3, ppy = 2-phenylpyridinyl, undergoes the chloride abstraction reaction using various AgX (X = PF6, BF4, NO3 and CH3COO) salts. Depending on the nature of anions in AgX salts (coordinating or noncoordinating), the products can be neutral or ionic. In the cases of NO3 and CH3COO, they can be coordinated to the Pt center so that the neutral complexes [Pt(ppy)(PPh3)(NO3)], 4a, and [Pt(ppy)(PPh3)(CH3COO)], 4b, are formed. In contrast, the ionic complexes [{Pt(ppy)(PPh3)(CH3CN)}PF6], 5a, and [{Pt(ppy)(PPh3)(CH3CN)}BF4], 5b, can be generated when the AgPF6 ([{Ag(CH3CN)4}PF6]) or AgBF4 ([{Ag(CH3CN)4}BF4]) salts are used in which the PF6 and BF4 stand as counteranions. In these two complexes, CH3CN fills the empty ligand position which can be present as solvent or ligand in the initial silver salts. The structures of the new complexes were accurately deduced from the multinuclear (1H, 31P{1H}, 195Pt{1H}) NMR spectroscopy and further authenti...

Oxygen Atom Transfer to Cationic PCPNi(II) Complexes Using Amine-N-Oxides.

Three PCsp3P pincer ligands differing in the aryl group linking the phosphine arms with the anchoring carbon donor were used to support square planar Ni(II) bromide complexes 1-3Br. Exchange of the coordinating bromide anion for the more weakly coordinating triflate (OTf) or hexafluoroantimonate (SbF6) anions was accomplished by treatment with AgX or TlX salts to give compounds 1-3X; compounds 1OTf, 1SbF6, 2Br, 2OTf, 3Br, and 3SbF6 were all characterized by X-ray crystallography. The reactions of these Ni(II) compounds with the amine-N-oxide oxygen atom transfer agents ONMe3 and ONMePh2 were explored. For ONMe3, reactions with 2 equiv gave products in which one arm of the pincer ligand was oxidized to a P═O unit, with the other amine-N-oxide ligated to the Ni(II) center, forming products 5-6X; compounds 4OTf, 5OTf, and 6SbF6 were characterized crystallographically. Transient amine-N-oxide adducts prior to ligand oxidation were observed in some reactions. For the more effective O atom donor ONMePh2, reactions were very rapid and a second oxidation of the remaining phosphine arm was observed, producing a Ni(II) species with an OCO pincer ligand (7SbF6). All compounds were fully characterized. Experiments aimed at trapping transient Ni(IV) oxo intermediates (with cyclohexadiene, KH, and various Lewis acids) indicated that such species were not involved in the reaction. This was supported by density functional theory (DFT) computations at the B3PW91 level, which indicated that direct O atom insertion into the Ni-P bonds without the intermediacy of a Ni oxo species was the low-energy pathway.

Coordination polymers of silver(I) with ditopic cross-conjugated dienone

The reaction of the silver salts AgX (a: X = BF4-, b: X = ClO4-, c: X = OTf–) with α,α'-di(3/4-pyridylmethylene)cycloalkanones (L1–L3) and piperidones (L4–L7) results in the formation of coordination products of general composition [AgX(L n )(solvent)] and [AgX(L n )] (L n = L1–L7). All complexes were characterized by elemental analysis and IR-spectroscopy. The structures of [Ag(ClO4)(L1)(MeC≡N)]∞ (1b · MeC≡N) and [Ag(ClO4)(L1)]∞ (1b) in the solid state are reported. In both structures {Ag(L1)}+ building units are linked to each other via Ag–Npyridine primary bonds resulting in the formation of infinite chains. In both structures the ligands L1 are fixed in transoid conformations, thus forming zig-zag polar chains. The structure of 1b · MeC≡N consists of pairs of tightly and loosely stacked chains. The tightly packed chains are weakly coupled by perchlorate anions acting as μ-bridges in between Ag(I) centers as well as by π–π-stacking interactions of unsaturated fragments of the respective ligands. In contrast, polar 2D layers composed of {Ag(L1)} m m+ chains, which interdigitate via multiple weak interactions by Ag–O contacts, are found in the solid structure of 1b. The dissolution of coordination products in coordinating solvents like MeCN or DMSO leads to the decomposition of complexes due to formation of silver-solvent coordination compounds. The coordination products 1–5 are stable in solid state against exposure to the ambient light, whereas solutions of the compounds, especially in DMSO-d6, appeared to be photochemically labile. As revealed by NMR spectroscopic studies, the organic components undergo trans-cis isomerization.

Solvent and anion effects on the organization of a luminescent [2 + 2] BODIPY/Ag(i) metallamacrocycle in the crystalline state

The assembly of a novel BODIPY bearing peripheral vinyl–benzonitrile groups with AgX salts (X− = AsF6−, BF4−, ClO4−) leads to the recurrent formation of a [2 + 2] [Ag2(BODIPY)2]2+ type metallamacrocycle featuring emission in the crystalline state.

Structure and Reaction Chemistry of Magnesium Organocuprates Derived from Magnesiacyclopentadienes and Copper(I) Salts

AbstractThe chemistry of magnesium organocuprates, including their synthesis, structures, and reactions, remains underexplored. In this work, by taking advantage of the high reactivity and ready availability of magnesiacyclopentadienes, a series of magnesiacyclopentadiene‐based organocuprates were synthesized and structurally characterized. A variety of CuX salts (X=Cl, Br, I, or alkynyl) were successfully applied to react with magnesiacyclopentadienes. Besides CuX salts, AgX salts (X=Cl, alkynyl) also undergwent the above reaction to afford the corresponding magnesium organoargentates. Single‐crystal X‐ray structural analysis and DFT calculations of these butadienyl magnesium organocuprates revealed unique structural characteristics and bonding modes. These results are also very useful to understand the transmetalation process, since the product can be viewed as the resting‐state intermediate of a transmetalation reaction between organomagnesium compounds and coinage‐metal salts. Preliminary information on the reaction chemistry of these magnesium organocuprates is provided by their reactions with allyl bromide, benzoyl chloride, and CO2.

Structure and Reaction Chemistry of Magnesium Organocuprates Derived from Magnesiacyclopentadienes and Copper(I) Salts.

The chemistry of magnesium organocuprates, including their synthesis, structures, and reactions, remains underexplored. In this work, by taking advantage of the high reactivity and ready availability of magnesiacyclopentadienes, a series of magnesiacyclopentadiene-based organocuprates were synthesized and structurally characterized. A variety of CuX salts (X=Cl, Br, I, or alkynyl) were successfully applied to react with magnesiacyclopentadienes. Besides CuX salts, AgX salts (X=Cl, alkynyl) also undergwent the above reaction to afford the corresponding magnesium organoargentates. Single-crystal X-ray structural analysis and DFT calculations of these butadienyl magnesium organocuprates revealed unique structural characteristics and bonding modes. These results are also very useful to understand the transmetalation process, since the product can be viewed as the resting-state intermediate of a transmetalation reaction between organomagnesium compounds and coinage-metal salts. Preliminary information on the reaction chemistry of these magnesium organocuprates is provided by their reactions with allyl bromide, benzoyl chloride, and CO2 .

Just Add Salt: A Mass Spectrometric Analysis Method for Imaging Anion‐Exchanged Poly(Ionic Liquid)s

We report the first mass spectrometric analysis of poly(ionic liquid)s (PILs) containing weakly coordinating anions introduced by a fast, simple, and quantitative postmodification method on the example of the hydrophilic, well-defined poly(vinylbenzylpyridinium chloride) p([VBPy]Cl) species, analyzed with an in-source collision induced dissociation-Orbitrap mass spectrometry (MS) protocol. Using the MS approach allows for the precise structural elucidation of ion-exchanged p([VBPy]Cl) utilizing AgX (X = NO3- , CF3 CO2- , BF4- ) salts. The anion exchange is shown to be quantitative - without observing residual chlorinated PIL - on rapid time scales, using only filtration as a standard procedure during sample preparation. In addition, the influence of weakly coordinating anions on the ionization behavior of PILs is studied in detail.

Influence of Ancillary Ligands and Isomerism on the Luminescence of Bis-cyclometalated Platinum(IV) Complexes

The synthesis, characterization, and photophysical properties of a wide variety of bis-cyclometalated Pt(IV) complexes featuring a C2-symmetrical or unsymmetrical {Pt(ppy)2} unit (sym or unsym complexes, respectively; ppy = C-deprotonated 2-phenylpyridine) and different ancillary ligands are reported. Complexes sym-[Pt(ppy)2X2] (X = OTf(-), OAc(-)) were obtained by chloride abstraction from sym-[Pt(ppy)2Cl2] using the corresponding AgX salts, and the triflate derivative was employed to obtain homologous complexes with X = F(-), Br(-), I(-), trifluoroacetate (TFA(-)). Complexes unsym-[Pt(ppy)2(Me)X] (X = OTf(-), F(-)) were prepared by reacting unsym-[Pt(ppy)2(Me)Cl] with AgOTf or AgF, respectively, and the triflate derivative was employed as precursor for the synthesis of the homologues with X = Br(-), I(-), or TFA(-) through its reaction with the appropriate anionic ligands. The previously reported complexes unsym-[Pt(ppy)2X2] (X = Cl(-), Br(-), OAc(-), TFA(-)) are included in the photophysical study to assess the influence of the arrangement of the cyclometalated ligands. Density functional theory (DFT) and time-dependent DFT calculations on selected derivatives were performed for a better interpretation of the observed excited-state properties. Complexes sym-[Pt(ppy)2X2] (except X = I(-)) exhibit phosphorescent emissions in fluid solutions at 298 K arising from essentially (3)LC(ppy) excited states, which are very similar in shape and energy. However, their efficiencies are heavily dependent on the nature of the ancillary ligands, which affect the energy of deactivating ligand-to-ligand charge transfer (LLCT) or ligand-to-metal charge transfer (LMCT) states. The fluoride derivative sym-[Pt(ppy)2F2] shows the highest quantum yield of this series (Φ = 0.398), mainly because the relatively high metal-to-ligand charge transfer admixture in its emitting state leads to a high radiative rate constant. Complexes unsym-[Pt(ppy)2X2] emit from (3)LC(ppy) states in frozen matrices at 77 K, but their emissions are totally quenched in fluid solution at 298 K because of the presence of low-lying, dissociative LMCT excited states, which also cause photoisomerization reactions. Complexes unsym-[Pt(ppy)2(Me)X] (X = F(-), Cl(-), Br(-), TFA(-)) show strong emissions in fluid solutions at 298 K (Φ = 0.52-0.63) because deactivating LMCT states lie at high energies. However, derivative unsym-[Pt(ppy)2(Me)I] is only weakly emissive at 298 K because of the presence of low-lying LLCT [p(I) → π*(ppy)] states.

Molecular tectonics: dimensionality and geometry control of silver coordination networks based on pyrazolyl appended thiacalixarenes

Combinations of six new tetrakis-pyrazolyl appended calix[4]arenes derivatives, blocked in 1,3-A conformation as coordinating tectons, with AgX salts (X = NO3−, BF4−, XF6−(X = P, As and Sb)) lead to nine new silver coordination networks.

Silver(I) complexes with phthalazine and quinazoline as effective agents against pathogenic Pseudomonas aeruginosa strains

Five silver(I) complexes with aromatic nitrogen-containing heterocycles, phthalazine (phtz) and quinazoline (qz), were synthesized, characterized and analyzed by single-crystal X-ray diffraction analysis. Although different AgX salts reacted with phtz, only dinuclear silver(I) complexes of the general formula {[Ag(X-O)(phtz-N)]2(μ-phtz-N,N′)2} were formed, X=NO3− (1), CF3SO3− (2) and ClO4− (3). However, reactions of qz with an equimolar amount of AgCF3SO3 and AgBF4 resulted in the formation of polynuclear complexes, {[Ag(CF3SO3-O)(qz-N)]2}n (4) and {[Ag(qz-N)][BF4]}n (5). Complexes 1–5 were evaluated by in vitro antimicrobial studies against a panel of microbial strains that lead to many skin and soft tissue, respiratory, wound and nosocomial infections. The obtained results indicate that all tested silver(I) complexes have good antibacterial activity with MIC (minimum inhibitory concentration) values in the range from 2.9 to 48.0μM against the investigated strains. Among the investigated strains, these complexes were particularly efficient against pathogenic Pseudomonas aeruginosa (MIC=2.9–29μM) and had a marked ability to disrupt clinically relevant biofilms of strains with high inherent resistance to antibiotics. On the other hand, their activity against the fungus Candida albicans was moderate. In order to determine the therapeutic potential of silver(I) complexes 1–5, their antiproliferative effect on the human lung fibroblastic cell line MRC5, has been also evaluated. The binding of complexes 1–5 to the genomic DNA of P. aeruginosa was demonstrated by gel electrophoresis techniques and well supported by molecular docking into the DNA minor groove. All investigated complexes showed an improved cytotoxicity profile in comparison to the clinically used AgNO3.

A Silver Bite: Crystalline Heterometallic Architectures Based on Ag–π Interactions with a Bis‐Dipyrrin Zinc Helicate

An unprecedented mode of assembly of helical motives and Ag(I) ions in the crystalline state is described. The combination of a Zn(II) helicate based on a 2,2'-bisdpm bearing peripheral benzonitrile moieties with AgX salts, leads to the formation of a tetranuclear core containing Ag-π interactions. Depending on the coordinating ability of the X(-) anion and the solvents used, the tetranuclear complex self-assembles into coordination polymers of varying dimensionality. From the sequence of coordination events (Ag-π or Ag-peripheral site), one may envisage two possible construction scenarios. However, the Ag-π as primary event seems reasonable owing to the rather weak binding propensity of the nitrile group and the chelating nature of the π-clefts.

Cu(I) and Ag(I) complexes of 7,10-bis-N-heterocycle-diazafluoranthenes: programmed molecular grids?

Reactions of 7,10-disubstituted diazafluoranthene derivatives with three different silver(I) salts AgX (X = [PF6](-), [SbF6](-), [CB11HCl11](-)) and [Cu(CH3CN)4]PF6 afforded complexes exhibiting five different motifs. The crystal structures of the free ligands and nine new complexes from this series of reactions are reported. The use of 2,5-di-tert-butyl-7,10-di(pyridin-2-yl)-8,9-diazafluoranthene as a ligand leads to the formation of the tetranuclear compounds [Ag4(C32H30N4)4][PF6]4·3C6H6·4MeCN, [Ag4(C32H30N4)4][SbF6]4·4C5H12 and [Cu4(C32H30N4)4][PF6]4·8C3H6O, which exhibit "propeller" and saddle-type geometry, respectively, as well as a dinuclear complex [Ag2(C32H30N4)2][CHB11Cl11]2·4C6H4Cl2·CH2Cl2. The reactions involving the less sterically hindered 2,5-di-tert-butyl-7,10-di-(pyrimidin-2-yl)-8,9-diazafluoranthene and 2,5-di-tert-butyl-7,10-di(thiazol-2-yl)-8,9-diazafluoranthene afforded crystals of the dinuclear complexes [Ag2(C30H28N6)2][PF6]2·0.5CH2Cl2·0.5C6H5Cl·0.5C6H12, [Ag2(C30H28N6)2][SbF6]2·C3H6O·0.5C6H14·0.5C6H6, the polymeric species [Ag2(C28H26N4S2)2]n·2n[PF6]n·nC3H6O and the tetranuclear compounds [Cu4(C26H25N4S2)4][PF6]4·2CHCl3·2C3H6O and [Cu4(C30H28N6)4][PF6]4·2.17H2O, which possess saddle and grid-like architectures, respectively. Conformational analysis of the free ligands showed that they exhibit N-C-C-N torsion angles ranging from syn clinal (58°) to fully anti-periplanar conformations; the syn clinal conformation dominates in the complexes. The relative energies of the possible structural conformations of the synthesized ligands, as well as of oxazole disubstituted diazafluoranthenes, were calculated using density functional theory at the B97D/Def2-TZVPP level of theory.

Molecular tectonics: anion control of dimensionality and connectivity in meta-pyridyl appended tetramercaptotetrathiacalix[4]arene based silver coordination networks

The combination of the same organic tecton 1, a meta-pyridyl appended tetramercaptotetrathiacalix[4]arene in 1,3-alternate conformation offering four pyridyl units and eight thioether groups, with three silver salts AgX (X = BF4(-), NO3(-) and SbF6(-)) leads, under identical conditions (concentration, temperature and solvent system), to the formation of different silver coordination networks. Both the connectivity and the dimensionality of the three silver coordination networks depend on the nature of the anion used as a counter ion. Whereas the weakly coordinating BF4(-) anion does not participate in the formation of the non-tubular 1D coordination network, the coordinating NO3(-) anion is bound to the metal cation and this leads to the formation of a tubular 1D silver coordination network. In both cases, the eight S atoms of the tecton 1 do not take part in the binding of the cation. In marked contrast, when the SbF6(-) anion is used as a counter ion, the organic tecton 1 behaves as a tetrakismonodentate through its four meta-pyridyl moieties and as a bischelating unit of the SCCS type leading thus to the formation of a porous 3D diamondoid-type network.

Synthesis, Structure, and Luminescent Behavior of Anionic Oligomeric and Polymeric Ag2Au2 Clusters

Mixtures of silver salts AgX (X = NO3, CF3CO2, CF3SO3) with M[Au(C6F5)2] (M = NBu4, PPh4) gave respectively the ionic mixed-metal clusters [M2{(C6F5)4Au2Ag2X2}]n (1, X = NO3; a, M = NBu4; b, M = PPh4) and [M{(C6F5)4Au2Ag2X}]n, (2a,b, X = CF3CO2; 3a,b, X = CF3SO3). The degree of aggregation n of these cluster compounds depends strongly on the method of isolation (solvent evaporation or precipitation); for example, recrystallization of 1a gave a crystalline salt of the tetraanion [(C6F5)4Au2Ag2X2]24– as well as the polymer [(NBu4)2{(C6F5)4Au2Ag2(NO3)2}]n. The aurophilic Au···Au interactions strongly influence the photoemission wavelength. The anion X has remarkably little effect on the luminescence color but strongly influences the conformation of the polyanionic chains, leading to a variety of solid-state structures, from well-defined dimers (1a1) to linear (1b) and curved (1a2, 2a) polymeric chain aggregates.