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Pyridine-2-carboxylate (pic) has been employed extensively as a blue-shifting ancillary ligand in the production of cyclometalated iridium complexes used in OLEDs, but surprisingly, further elaboration of this ligand has largely been unexplored. In this work we demonstrate a simple and versatile route for modifying picolinate ligands coordinated to iridium. Reacting a μ-chloro iridium(C∧N) dimer (where C∧N is a phenylpyridine-based ligand) with 4-bromopicolinic acid (HpicBr) yields the corresponding iridium(C∧N)2(picBr) complexes, which were readily modified by a Suzuki–Miyaura reaction to give the corresponding aryl-substituted picolinate complexes. The luminescent behavior of these complexes shows that by restricting the torsional angle between the substituent and pic the emission can be shifted by up to 77 nm.

A simple and versatile route for modifying picolinate ligands coordinated to iridium is described. Reacting a μ-chloro iridium(C∧N) dimer (where C∧N is a phenylpyridine-based ligand) with bromopicolinic acid (HpicBr) yields the corresponding iridium(C∧N)2(picBr) complexes (1–4 and 11), which were readily modified by a Sonogashira reaction to give eight alkyne-substituted picolinate complexes (5–10, 12, and 13). The luminescent behavior of these complexes shows that the position of substitution about the picolinate ring has an effect on both photophysical behavior as well as the reactivity.

Volume 62, no. 8, e02576-17, 2018, [https://doi.org/10.1128/AAC.02576-17][1]. This article was published on 27 July 2018 with the second author's surname incorrectly indexed as “del Carmen Parquet” instead of “Parquet.” This has been corrected in the current version, posted on 7 December

Improving the spatial alignment of emitting molecules has long been a goal of organic-light-emitting-diode development to improve device efficiencies and to generate polarized emission. Herein we describe a simple approach employing Sonogashira coupling with alkyne iridium(phenylpyridine)2(acetylacetone) synthons (2-5) to generate eight linear iridium complexes (6-13) with crystallographically determined lengths of up to 5 nm. By embedding these "long" complexes into a polymer matrix and stretching it, an improvement of the polarization ratio of unstretched and stretched films of up to 7.1 times was achieved. Additionally, through the inclusion of "twists" in the complexes, the electronic coupling between the iridium center and substituent was controlled, giving a system where the emission behavior is independent of the length.

DIBI, a purpose-designed hydroxypyridinone-containing iron-chelating antimicrobial polymer was studied for its anti-staphylococcal activities in vitro in comparison to deferiprone, the chemically related, small molecule hydroxypyridinone chelator. The sensitivities of 18 clinical isolates of Staphylococcus aureus from human, canine and bovine infections were determined. DIBI was strongly inhibitory to all isolates, displaying approximately 100-fold more inhibitory activity than deferiprone when compared on their molar iron-binding capacities. Sensitivity to DIBI was similar for both antibiotic-resistant and -sensitive isolates, including hospital- and community-acquired (United States 300) MRSA. DIBI inhibition was primarily bacteriostatic in nature at low concentration and was reversible by addition of Fe. DIBI also exhibited in vivo anti-infective activity in two distinct MRSA ATCC43300 infection and colonization models in mice. In a superficial skin wound infection model, topical application of DIBI provided a dose-dependent suppression of infection along with reduced wound inflammation. Intranasal DIBI reduced staphylococcal burden by >2 log in a MRSA nares carriage model. DIBI was also examined for its influence on antibiotic activities with a reference isolate ATCC6538, typically utilized to assess new antimicrobials. Sub-bacteriostatic concentrations of DIBI resulted in Fe-restricted growth and this physiological condition displayed increased sensitivity to GEN, CIP, and VAN. DIBI did not impair antibiotic activity but rather it enhanced overall killing. Importantly, recovery growth of survivors that typically followed an initial sub-MIC antibiotic killing phase was substantially suppressed by DIBI for each of the antibiotics examined. DIBI has promise for restricting staphylococcal infection on its own, regardless of the isolate’s animal source or antibiotic resistance profile. DIBI also has potential for use in combination with various classes of currently available antibiotics to improve their responses.

The single molecule conductances of a series of bis-2,2':6',2″-terpyridine complexes featuring Ru(II), Fe(II), and Co(II) metal ions and trimethylsilylethynyl (Me3SiC≡C-) or thiomethyl (MeS-) surface contact groups have been determined. In the absence of electrochemical gating, these complexes behave as tunneling barriers, with conductance properties determined more by the strength of the electrode-molecule contact and the structure of the "linker" than the nature of the metal-ion or redox properties of the complex.

Six complexes consisting of either 2,6-bis(1H-benzimidazol-2-yl)pyridine (bbp) or 2,2′:6′,2″-terpyridine (tpy) moieties coordinated to ruthenium(II) and attached to (pentaphenoxy)cyclotriphosphazene were synthesised and structurally characterised by single-crystal X-ray diffraction techniques. Two of the complexes are the first examples of structurally characterised mono-protonated Ru(bbp)(tpy) complexes. The new complexes were studied by NMR, electronic absorption and vibration spectroscopy to gain an understanding of their physical characteristics. Remarkably the mono-deprotonated form of the bbp ligand, but only when attached to (pentaphenoxy)cyclotriphosphazene by a pyridyl phosphoester linker, shows an equivalence of the benzimidazole/benzimidazolate moieties on the NMR time scale, but not on the electronic time scale, as evidenced by UV–Vis and resonance Raman spectroscopy.

The ligands 4'-(4-(methylthio)phenyl)-2,2':6',2″-terpyridine (L(1)), 4'-((4-(methylthio)phenyl)ethynyl)- 2,2':6',2″-terpyridine (L(2)), and bis(tridentate) bridging ligand 2,3,5,6-tetra(pyridine-2-yl)pyrazine (tpp) were used to prepare the complexes [Ru(L(1))2][PF6]2 ([1][PF6]2, [Ru(L(2))2][PF6]2 ([2][PF6]2), [{(L(1))Ru}(μ-tpp){Ru(L(1))}][PF6]4 ([3][PF6]4), and [{(L(2))Ru}(μ-tpp){Ru(L(2))}][PF6]4 ([4][PF6]4). Crystallographically determined structures give S···S distances of up to 32.0 Å in [4](4+). On the basis of electrochemical estimates, the highest occupied molecular orbitals of these complexes fall between -5.55 and -5.85 eV, close to the work function of clean gold (5.1-5.3 eV). The decay of conductance with molecular length across this series of molecules is approximately exponential, giving rise to a decay constant (pseudo β-value) of 1.5 nm(-1), falling between decay factors for oligoynes and oligophenylenes. The results are consistent with a tunnelling mechanism for the single-molecule conductance behavior.

The synthesis of a series of cyclotriphosphazene and polyphosphazene ruthenium(II) compounds is reported using 2,2′:6′,2″-terpyridine (terpy) and 2,6-di(1H-pyrazol-1-yl)pyridine (bpp) pendant ligands. X-ray crystallography, UV–Vis and resonance Raman spectroscopy have been employed to gain an insight into the physical and coordination behaviour of these complexes and indicate that both the small molecule and their polymeric analogues contain coordinated Ru in an octahedral ‘N6’ environment. The results reveal a difference between the chemistry of the ruthenium(II)-bpp-terpy and ruthenium(II)-bis-terpy complexes and demonstrate a means of grafting functional groups to a polyphosphazene backbone under mild conditions.

Candida albicansis an important opportunistic pathogen causing various human infections that are often treated with azole antifungals. The U.S. CDC now regards developing candidal antifungal resistance as a threat, creating a need for new and more effective antifungal treatments. Iron is an essential nutrient for all living cells, and there is growing evidence that interference with iron homeostasis ofC. albicanscan improve its response to antifungals. This study was aimed at establishing whether withholding iron by currently used medical iron chelators and the novel chelator DIBI could restrict growth and also enhance the activity of azoles against clinical isolates ofC. albicans. DIBI, but not deferoxamine or deferiprone, inhibited the growth ofC. albicansat relatively low concentrationsin vitro, and this inhibition was reversed by iron addition. DIBI in combination with various azoles demonstrated stronger growth inhibition than the azoles alone and greatly prolonged the inhibition of cell multiplication. In addition, the administration of DIBI along with fluconazole (FLC) to mice inoculated with an FLC-sensitive isolate in a model of experimentalC. albicansvaginitis showed a markedly improved clearance of infection. These results suggest that iron chelation by DIBI has the potential to enhance azole efficacy for the treatment of candidiasis.

Tris(2-cyanoethyl)phosphine (tcep) reacts with the copper(I) compounds, CuX (X = Cl, Br, I and SCN), in a 1:1 ratio to give 1:1 complexes, CuX(tcep), whereas it reacts with CuY (Y = PF 6 , ClO 4 , NO 3 , BH 4 , CN and CF 3 COO) in a 2:1 ratio to give the 2:1 complexes, CuY(tcep) 2 . Single crystal X-ray structures show that for the anions X = Br and SCN, the complexes are coordination polymers, [CuX(tcep)] n , with the Cu centres being bridged by the anion, and as well, one nitrile arm per tcep ligand coordinates intermolecularly to the Cu to give tetrahedral ‘PBr 2 N’ and ‘PSN 2 ’ coordination spheres respectively. The 2:1 compounds exhibit a variety of structures. For Y = ClO 4 , CN and CF 3 COO polymeric structures are formed except for Y = BH 4 where the compound is a discrete monomer, [Cu(BH 4 )(tcep) 2 ], with a chelating anion and two monodentate P-bound tcep ligands. Both the compounds obtained with Y = CN and CF 3 COO also contain coordinated anions and are formulated as [Cu(CN)(tcep) 2 ] n and [Cu(CF 3 COO)(tcep) 2 ] n respectively. In the case of Y = CN the anion is bridging and the tcep ligands are only P-bound giving a ‘P 2 NC’ coordination sphere. In contrast, for Y = CF 3 COO, the anion is an O-bound monodentate and the tcep ligands bridge to give a ‘P 2 NO’ environment for the copper. In the case of Y = ClO 4 , the anion is not coordinated but a polymeric structure, [Cu(tcep) 2 ] n (ClO 4 ) n , is formed via bridging tcep ligands linking Cu centres intermolecularly resulting in a ‘P 2 N 2 ’ coordination sphere.

Mossbauer and electronic absorbance spectroscopy along with variable temperature magnetic moment measurements demonstrate that a cyclotriphosphazene substituted with an iron(II)-bis-2,6-di(1H-pyrazoly-yl)pyridine moiety ( 1 ) and its polyphosphazene analogue ( 2 ) differ significantly in magnetic behaviour.

The synthesis of the new cyclotriphosphazene (CTP) ligand substituted with a pendant 2,6-bis(benzimidazole-2-yl)pyridine (bbp), namely (pentaphenoxy)[4-{2,6-bis(benzimidazole-2-yl)pyridine-4-yl}phenoxy]cyclotriphosphazene L is reported. The single crystal structure of L shows that the bbp group is attached to the CTP via the oxygen. L reacts with FeX2 (X = ClO4− or BF4-) salts forming the [FeL2]X2 complexes 1 and 2 respectively. For [FeL2](BF4)2 (2), the single crystal structure shows an ‘N6’ coordination sphere around the iron atom. UV–Vis, resonance Raman and Mossbauer spectroscopies and magnetic susceptibility measurements, aided by density functional theory (DFT) calculations, determine the complexes are low spin below 300 K but display spin crossover (SCO) behavior above this temperature, hence showing that the addition of a phosphazene to a SCO moiety does not prevent SCO.

Two new cyclotriphosphazene ligands with pendant 2,2':6',2″-terpyridine (Terpy) moieties, namely, (pentaphenoxy){4-[2,6-bis(2-pyridyl)]pyridoxy}cyclotriphosphazene (L(1)), (pentaphenoxy){4-[2,6-terpyridin-4-yl]phenoxy}cyclotriphosphazene (L(2)), and their respective polymeric analogues, L(1P) and L(2P), were synthesized. These ligands were used to form iron(II) complexes with an Fe(II)Terpy(2) core. Variable-temperature resonance Raman, UV-visible, and Mössbauer spectroscopies with magnetic measurements aided by density functional theory calculations were used to understand the physical characteristics of the complexes. By a comparison of measurements, the polymers were shown to behave in the same way as the cyclotriphosphazene analogues. The results showed that spin crossover (SCO) can be induced to start at high temperatures by extending the spacer length of the ligand to that in L(2) and L(2P); this combination provides a route to forming a malleable SCO material.

Two new polyphosphazene ligands containing 1,10-phenanthrolin-2-olate (L1) and 2,2ʹ-bipyridine-6-olate moieties (L2) with 5,5ʹ-di-tert-butylbiphenyl-2,2ʹ-bis(olate) co-substituents were synthesised and then reacted with Fe(Pyridine)4(NCS)2. Variable temperature Mossbauer and electronic absorbance spectroscopies were used to establish the physical behaviour of the new iron-polyphosphazenes. By attaching two bidentate ligands to a geminal phosphorus atom a pseudo tetradentate ligand can be formed that prevents cross-linking when iron is coordinated to the polyphosphazene.

The metal-nitrogen bond in six-coordinate complexes [ML 1 C1] + (M = Co, Ni, Cu or Zn) of (pyridyloxy)cyclophosphazene, five-coordinate complexes [ML 1 Cl 2 ] (M = Cu or Zn) of green-[NiL 1 Cl 2 ], and dimetallic complexes [L 2 (CuCl 2 ) 2 ], [L 3 (CuCl 2 ] 2+ and [L 3 (CuCl 2 ) 2 ] [L 1 = hexakis(2-pyridyloxy)-cyclotriphosphazene, L 2 = hexakis(4-methyl-2-pyridyloxy)-cyclotriphosphazene or L 3 = octakis(4-methyl-2-pyridyloxy)-cyclotetraphosphazene] of red-[NiL 1 Cl 2 ], has been investigated by using density functional theory (DFT) and natural bond order (NBO) analysis. The calculations show that the divalent metal ions bind to the phosphazene ring nitrogen by a σ-type bond and that the lengthening of the PN bonds, which flank the metal coordination site, can be explained as a result of electron density that is transferred from PN bonding orbitals to the 4s orbital of the metal ion rather than a decrease in the π component of the bond as suggested by earlier models. It can be assumed that this explanation of the bonding is valid for the wide range of metallo-phosphazene complexes and that metal ions will bind to the PN backbone of polyphosphazenes in a similar manner.

Copper(II) chloride and bromide react with the pyridyloxy-substituted cyclotetraphosphazene ligands, octakis(2-pyridyloxy)cyclotetraphosphazene (L(1)), and octakis(4-methyl-2-pyridyloxy)cyclotetraphosphazene (L(2)), to form the dimetallic complexes, [L(CuX2)2] (L = L(1), X = Br; L = L(2), X = Cl or Br), and [{L(1)(CuCl2)2}n]. Single crystal X-ray crystallography shows the complex [{L(1)(CuCl2)2}n] to be a coordination polymer propagated by interligand "Cu(mu-Cl)2Cu" bridges whereas [L(2)(CuCl2)2] forms discrete dimetallic cyclotetraphosphazene-based moieties. The variable temperature magnetic susceptibility data for [{L(1)(CuCl2)2}n] are consistent with a weak antiferromagnetic exchange interaction between the copper(II) centers occurring via the bridging chloride ions. [L(2)(CuCl2)2] and [L(CuBr2)2] (L = L(1) and L(2)) exhibit normal Curie-like susceptibilities. The abstraction of a chloride ion, using [Ag(MeCN)4](PF6), from each copper site in [L(2)(CuCl2)2], affords the new complex, [L(2)(CuCl)2](PF6)2, in which the two copper(II) ions are separated by "N-P=N-P=N" phosphazene bridges. Electron spin resonance and variable temperature magnetic measurements indicate the occurrence of weak antiferromagnetic coupling between the unpaired electrons on the copper(II) centers. Density Functional Theory (DFT) calculations on the [L(2)(CuCl)2](2+) dication and the related cyclotriphosphazene complex, [L(4)(CuCl2)2] (L(4) = hexakis(4-methyl-2-pyridyloxy)cyclotriphosphazene), have identified "electron-density-bridge" molecular orbitals which involve Cu 3d orbitals overlapping with the non-bonding N-based molecular orbitals on the phosphazene rings as the pathway for this interaction.

Real-time PCR is a powerful tool for the detection and typing of herpes simplex virus (HSV). HSV types 1 and 2 can be distinguished by using the differences in the melting temperatures ( T m s) of the hybridization probes. The efficacy of T m profiling with low DNA concentrations was evaluated in this study.

The preparation and the single crystal X-ray structure of a new chiral ligand, 3,3,5,5-tetrapyridyloxy-1,1-{(R)-1,1′-dioxy-2,2′-binapthyl}cyclotriphosphazene (LR), is described. LR reacts with [Ag(MeCN)4]PF6 to produce the complex {[AgLR](PF6) · Et2O · 2MeCN}n, which was also characterised by X-ray crystallography. The topology of complex is a 1D coordination polymer that, in the crystalline structure, consists of two different infinite chains arranged in layers that are approximately orthogonal to each another.

The reaction between two equivalents of N -(2-hydroxyphenyl)- p -toluenesulfonamide (H 2 sulf) and [N 3 P 3 (biph) 2 Cl 2 ] (H 2 biph = 2,2′-biphenol) produces the compound bis (2,2′-biphenylato) bis (2-oxyphenyl)- p -toluenesulfonamide cyclotriphosphazene (H 2 L) containing two geminal Hsulf moieties. Further reaction of H 2 L in basic conditions results in the removal of the sulfonamide arm and the slow formation of a novel phosphazene containing the spirocyclic sulf moiety. When this occurs in the presence of [Pd(bpy)Cl 2 ] the reaction is facile and the new complex [Pd(bpy)(sulf)] ( 2 ) is also formed. Compounds H 2 L, 1 and 2 have all been characterised by single crystal X-ray crystallography.

The ethynyl-phenylene substituted 2,2':6',2''-terpyridine (tpy) derivatives, 4-(phenyl-ethynyl)-2,2':6',2''-terpyridine (L(1)), 4-(methoxyphenyl-ethynyl)-2,2':6',2''-terpyridine (L(2)), 4-(tolyl-ethynyl)-2,2':6',2''-terpyridine (L(3)) and 4-(nitrophenyl-ethynyl)-2,2':6',2''-terpyridine (L(4)) have been used to synthesize four new [RuCl(2,2'-bipyridine)(L(n))]PF6 based complexes. Electronic absorption, resonance Raman, cyclic voltammetry and spectroelectrochemistry aided by DFT calculations were used to explore the influence of the alkynyl substituents on the electronic structures, photochemical and redox properties of the complexes. Furthermore, it is shown that the addition of ethynyl phenyl moieties to the 4-position of the tpy ligand does not have a detrimental effect on these complexes, or the analogous aqua complexes, with respect to their ability to photocatalyse the oxidation of 4-methoxybenzyl alcohol to the corresponding benzaldehyde.

Legionella pneumophila expresses two catalase-peroxidase enzymes that exhibit strong peroxidatic but weak catalatic activities, suggesting that other enzymes participate in decomposition of hydrogen peroxide (H 2 O 2 ). Comparative genomics revealed that L. pneumophila and its close relative Coxiella burnetii each contain two peroxide-scavenging alkyl hydroperoxide reductase (AhpC) systems: AhpC1, which is similar to the Helicobacter pylori AhpC system, and AhpC2 AhpD (AhpC2D), which is similar to the AhpC AhpD system of Mycobacterium tuberculosis . To establish a catalatic function for these two systems, we expressed L. pneumophila ahpC1 or ahpC2 in a catalase/peroxidase mutant of Escherichia coli and demonstrated restoration of H 2 O 2 resistance by a disk diffusion assay. ahpC1 ::Km and ahpC2D ::Km chromosomal deletion mutants were two- to eightfold more sensitive to H 2 O 2 , tert -butyl hydroperoxide, cumene hydroperoxide, and paraquat than the wild-type L. pneumophila , a phenotype that could be restored by trans -complementation. Reciprocal strategies to construct double mutants were unsuccessful. Mutant strains were not enfeebled for growth in vitro or in a U937 cell infection model. Green fluorescence protein reporter assays revealed expression to be dependent on the stage of growth, with ahpC1 appearing after the exponential phase and ahpC2 appearing during early exponential phase. Quantitative real-time PCR showed that ahpC1 mRNA levels were ∼7- to 10-fold higher than ahpC2D mRNA levels. However, expression of ahpC2D was significantly increased in the ahpC1 mutant, whereas ahpC1 expression was unchanged in the ahpC2D mutant. These results indicate that AhpC1 or AhpC2D (or both) provide an essential hydrogen peroxide-scavenging function to L. pneumophila and that the compensatory activity of the ahpC2D system is most likely induced in response to oxidative stress.

We report on amino acid substitutions in the quinolone resistance-determining region of type II topisomerases and the prevalence of reserpine-inhibited efflux for 70 clinical isolates of S. pneumoniae for which the ciprofloxacin MIC is ≥4 μg/ml and 28 isolates for which the ciprofloxacin MIC is ≤2 μg/ml. The amino acid substitutions in ParC conferring low-level resistance (MICs, 4 to 8 μg/ml) included Phe, Tyr, and Ala for Ser-79; Asn, Ala, Gly, Tyr, and Val for Asp-83; Asn for Asp-78; and Pro for Ala-115. Isolates with intermediate-level (MICs, 16 to 32 μg/ml) and high-level (MICs, 64 μg/ml) resistance harbored substitutions of Phe and Tyr for Ser-79 or Asn and Ala for Asp-83 in ParC and an additional substitution in GyrA which included either Glu-85-Lys (Gly) or Ser-81-Phe (Tyr). Glu-85-Lys was found exclusively in isolates with high-level resistance. Efflux contributed primarily to low-level resistance in isolates with or without an amino acid substitution in ParC. The impact of amino acid substitutions in ParE was minimal, and no substitutions in GyrB were identified.

The structures of a series of tetracoordinate beryllium(II) complexes with ligands derived from tertiary-substituted amines have been computationally modeled and their (9)Be magnetic shielding values determined using the gauge-including atomic orbital (GIAO) method at the 6-311++g(2d,p) level. A good correlation was observed between calculated (9)Be NMR chemical shifts when compared to experimental values in polar protic solvents, less so for the values recorded in polar aprotic solvents. A number of alternative complex structures were modeled, resulting in an improvement in experimental versus computational (9)Be NMR chemical shifts, suggesting that in some cases full encapsulation on the beryllium atom was not occurring. Several of the synthesized complexes gave rise to unexpected fluorescence, and inspection of the calculated molecular orbital diagrams associated with the electronic transitions suggested that the rigidity imparted by the locking of certain conformations upon Be(II) coordination allowed delocalization across adjacent aligned aromatic rings bridged by Be(II).

We have identified an unusual group of viridans group streptococci that resemble Streptococcus pneumoniae . DNA-DNA homology studies suggested that a subset of these isolates represent a novel species that may be included in the S. oralis- S. mitis group of viridans group streptococci. We suggest that this novel species be termed Streptococcus pseudopneumoniae . A combination of phenotypic and genetic reactions allows its identification. S. pseudopneumoniae strains do not have pneumococcal capsules, are resistant to optochin (inhibition zones, less than 14 mm) when they are incubated under an atmosphere of increased CO 2 but are susceptible to optochin (inhibition zones, >14 mm) when they are incubated in ambient atmospheres, are not soluble in bile, and are positive by the GenProbe AccuProbe Pneumococcus test. The bile solubility test is more specific than the optochin test for identification of S. pneumoniae . Genetic tests for pneumolysin ( ply ) and manganese-dependent superoxide dismutase ( sodA ) and identification tests with a commercial probe, AccuProbe Pneumococcus, do not discriminate between the new species and S. pneumoniae .

The pyridyloxy-substituted cyclotetraphosphazene ligands, octakis(2-pyridyloxy)cyclotetraphosphazene (L), and octakis(4-methyl-2-pyridyloxy)cyclotetraphosphazene (MeL), react with [Ag(CH3CN)4]PF6 and [Ag(CF3SO3)] to form the complexes {[AgL](PF6)·0.5CH3CN·0.5C4H10O}n (1), {[Ag2L](PF6)2}n (2), [Ag2L](CF3SO3)2 (3), {[Ag2L](CF3SO3)2·C4H10O}n (4), {[Ag3(MeL)(CH3CN)2](PF6)3·2CH3CN}n (5), and [Ag4(MeL)(CF3SO3)(CH3CN)3](CF3SO3)3 (6), which have been characterized by single crystal X-ray crystallography. The structure of (1) is a coordination polymer containing repeating [AgL]+ units that form 1-D chains. The PF6− anions lie between the sheets formed when the individual chains approach each other such that the pendant pyridyloxy rings have numerous close intermolecular contacts. The triflate solvated salt (4) also is a 1-D coordination polymer, with the individual chains packed close together due to multiple hydrogen bonding contacts between the coordinated triflate fluorine atoms and aromatic hydrogen atoms on adjacent chains, whereas the unsolvated form (3) contains discrete molecules of a dimetallic complex. For the latter two complexes the influence of the solvent on the structures is notable and shows the flexibility of the ligand system. Complex (5) forms a 1-D coordination polymer with the chain being propagated by a silver bound in a near linear manner by a pyridyloxy pendant from one molecule, and by a pyridyloxy from an adjacent molecule. Apart from (4) and (6) all the compounds show this or a similar way of linking the units. Complex (6) forms discrete molecules of a tetra-metallic complex but with one silver involved in an argentophilic interaction at 3.408 A from its symmetry equivalent. This complex is the most metal-rich phosphazene reported for this ligand type, with all eight of the pyridine ligand arms involved in binding the four Ag(I) centres. The formation of silver-ligand bonds, hydrogen bonds, π–π stacking, argentophilic and anionic interactions along with subtle kinetic factors influence the self-assembly process.