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The coordinating properties of the bis(1,4‐dimethyl‐1,2,4‐triazol‐5‐ylidene) ligand (abbreviated as bitz) towards silver(I) and gold(I) centres have been explored. The bitz behaves as bridging ligand giving both dinuclear [M2(bitz)2](PF6)2 and trinuclear [M3(bitz)3](PF6)3 species, whose formation has been supported by X‐ray diffraction analysis, NMR spectroscopy and mass spectrometry evidences. The dinuclear and trinuclear gold(I) complexes present very similar luminescence properties, emitting in the blue region, at ~450 nm, when excited at 350 nm. Selected experimental aspects dealing with the synthesis of the dinuclear and trinuclear species, as well as with the absorption properties of the gold(I) complexes, have been investigated also through relativistic DFT calculations. [ABSTRACT FROM AUTHOR]

A series of novel asymmetrical bis-benzimidazolium salts were synthesized via a two-step alkylation process, yielding the benzimidazolium salts of N,N'-(ethane/propane/butane-1,2/3/4-diyl)-1-benzylbenzimidazolium-1'-(n-benzonitrile)benzimidazolium dibromide (n = 2,3,4) (1Br – 9Br). These salts served as carbene precursors for the subsequent formation of nitrile-functionalized asymmetrical silver(I) di-NHC complexes (Ag1 – Ag9) (NHC = N-heterocyclic carbene) through an in-situ deprotonation method using Ag2O. Comprehensive characterization of the bis-benzimidazolium salts and their corresponding dinuclear silver(I) di-NHC complexes was performed using melting point determination, CHN elemental analyses, FTIR, and 1H- and 13C-NMR spectroscopy. The successful complexation of nitrile-functionalized NHC ligands with silver(I) ions was evidenced by the disappearance of the acidic-carbene proton peak (δ 9.69 – 10.23 ppm) in the 1H-NMR spectra of the complexes. Furthermore, the formation of Ag-Ccarbene bonds was confirmed by the appearance of characteristic peaks in the 13C-NMR spectra of Ag1 – Ag9 (δ 170.89 – 195.90 ppm). To elucidate structure-property relationships, the Principal Component Analysis (PCA) was applied to the NMR spectroscopic data. The PCA of the 1H-NMR data revealed distinct clustering of bis-benzimidazolium salts and their respective silver(I) di-NHC complexes, with the first two principal components accounting for 71.40% of the total variance. Similarly, the PCA of the 13C-NMR data explained 72.08% of the total variance through the first two principal components. These results demonstrate the efficacy of PCA in differentiating and classifying the compounds based on their structural features and functional groups. Moreover, this study highlights the synergistic application of advanced spectroscopic techniques and chemometric analysis in inorganic synthesis chemistry subject and the insights gained from this approach contribute to a deeper understanding of the structural properties and potential applications of these novel NHC complexes, paving the way for future developments in organometallic chemistry and catalysis.

Melanoma, arguably the deadliest form of skin cancer, is responsible for the majority of skin-cancer-related fatalities. Innovative strategies concentrate on new therapies that avoid the undesirable effects of pharmacological or medical treatment. This article discusses the chemical structures of [(MTZ)2AgNO3], [(MTZ)2Ag]2SO4, [Ag(MCZ)2NO3], [Ag(MCZ)2BF4], [Ag(MCZ)2SbF6] and [Ag(MCZ)2ClO4] (MTZ—metronidazole; MCZ—miconazole) silver(I) compounds and the possible relationship between the molecules and their cytostatic activity against melanoma cells. Molecular Hirshfeld surface analysis and computational methods were used to examine the possible association between the structure and anticancer activity of the silver(I) complexes and compare the cytotoxicity of the silver(I) complexes of metronidazole and miconazole with that of silver(I) nitrate, cisplatin, metronidazole and miconazole complexes against A375 and BJ cells. Additionally, these preliminary biological studies found the greatest IC50 values against the A375 line were demonstrated by [Ag(MCZ)2NO3] and [(MTZ)2AgNO3]. The compound [(MTZ)2AgNO3] was three-fold more toxic to the A375 cells than the reference (cisplatin) and 15 times more cytotoxic against the A375 cells than the normal BJ cells. Complexes of metronidazole with Ag(I) are considered biocompatible at a concentration below 50 µmol/L. [ABSTRACT FROM AUTHOR]

Three Ag(I) bis(phenanthroline-oxazine) complexes with varying lipophilicity were synthesised and characterised. The solution stoichiometry of 1:2 Ag(I):ligand was determined for each complex by the continuous variation Job's plot method using NMR spectroscopy. NMR studies were also carried out to investigate the fluxional behaviour of the Ag(I) complexes in solution. The biological activity of the silver(I) complexes and the corresponding ligands towards a clinical strain of Candida albicans MEN was studied using broth microdilution assays. Testing showed the choice of media and the duration of incubation were key determinants of the inhibitory behaviour towards Candida albicans, however, the difference between freshly prepared and pre-prepared solutions was insignificant in minimal media. The activity of the metal-free ligands correlated with the length of the alkyl chain. In minimal media, the methyl ester phenanthroline-oxazine ligand was effective only at 60 μM, limiting growth to 67% of the control, while a 60 μM dose of the propyl ester analogue limited fungal growth at < 20% of the control. MIC50 and MIC80 values for the propyl and hexyl ester analogues were calculated to be 45 and 59 µM (propyl), and 18 and 45 µM (hexyl). Moreover, in a study of activity as a function of time it was observed that the hexyl ester ligand maintained its activity for longer than the methyl and propyl analogues; after 48 h a 60 μM dose held fungal growth at 24% of that of the control. Complexation to Ag(I) was much more effective in enhancing biological activity of the ligands than was increasing the ester chain length. Significantly no difference in activity between the three silver(I) complexes was observed under the experimental conditions. All three complexes were substantially more active than their parent ligands against Candida albicans and AgClO4 and the three silver(I) bis(phen-oxazine) complexes have MIC80 values of < 15 μM. The ability of the silver(I) complexes to hold fungal growth at about 20% of the control even after 48 h incubation at low dosages (15 μM) showcases their superiority over the simple silver(I) perchlorate salt, which ceased to be effective at dosages below 60 μM at the extended time point. [ABSTRACT FROM AUTHOR]

Silver(I) complexes of amantadine (atdH), memantine (mtnH) and rimantadine (rtdH), named Ag-atd, Ag-mtn and Ag-rtd, respectively, were recently synthesized and described in the literature as promising antibacterial agents. In the present study, the cytotoxicity of such complexes was evaluated against cultures of primary epidermal keratinocytes (HaCaT) and murine melanoma tumor cells (B16-F10), and mutagenicity was studied by the Ames test to investigate their abilities to induce gene mutations. The Ames test was performed using Salmonella Typhimurium strains (TA98, TA100, TA102 and TA97a) capable of detecting frameshift and base pair substitution gene mutations, in experiments with and without metabolic activation (microsomal fraction S9). This study revealed significant cytotoxic activity against tumor cells and selectivity of Ag-atd and Ag-rtd complexes when compared to non-tumor human keratinocyte cells. Moreover, the Ag(I) complexes did not induce a significant growth in the number of revertant colonies when comparing with the negative control, both in the experiments without and with metabolic activation, indicating absence of mutagenic activity. The results are encouraging and collaborate in the genotoxicological investigations necessary for understanding the interaction and ability of the silver complexes to induce mutations and contribute to ensure their uses as future antibacterial or antitumor agents.

In the present study, the structure, thermal stability, conductive properties, and antimicrobial activity of silver(I) complexes with nitrile ligands were investigated. For the construction of the materials, 2‐cyanopyridine (2‐cpy), 4‐cyanopyridine (4‐cpy), 1,2‐dicyanobenzene (1,2‐dcb), and 1,3‐dicyanobenzene (1,3‐dcb) were used in addition to the silver nitrite and nitrate. Four new compounds were isolated and structurally characterized: one molecular complex [Ag4(1,2‐dcb)4(NO3)4], two 1‐D coordination polymers [Ag(2‐cpy)2(NO2)]∞, [Ag2(1,3‐dcb)2(NO3)2]∞, and one 3‐D coordination polymer [Ag(4‐cpy)(NO2)]∞. The results indicate that the nitrile complexes display good antimicrobial properties against the tested bacterial and fungal strains. The presence of weakly coordinating CN groups increases the release of silver ions into the bacterial and yeast cell environments. Moreover, these materials exhibit unusual electrical properties in thin‐layer devices. On the other hand, the nitrite and nitrate counterions give rise to the low thermal stability of the complexes. [ABSTRACT FROM AUTHOR]

The design of red‐emitting silver(I) complexes and their implementation in thin‐film lighting are still challenging as (i) their high ligand‐field splitting energy leads to high‐energy emissions with a controversial mechanism (thermally activated delayed fluorescence vs fluorescence/phosphorescence), and (ii) their low electrochemical stability leads to the formation of silver nanoclusters, limiting device stability to a few seconds. Herein, a thoughtful complex design [Ag(xantphos)(deebq)]PF6 combining a large‐bite angle diphosphine ligand (xantphos), a rigid, sterically hindered, π‐extended biquinolin (deebq) is reported. In contrast to prior‐art, this complex possesses (i) efficient red‐emission (λem = 660 nm; photoluminescence quantum yield of 42%) assigned to a thermally equilibrated dual‐phosphorescent emission based on spectroscopic/theoretical studies and (ii) stable reduction behavior without forming silver nanoclusters. This results in the first red light‐emitting electrochemical cells featuring (i) improved stability of two orders of magnitude compared to prior‐art (from seconds to hours) at irradiances of 20 µW cm−2, and (ii) a new degradation mechanism exclusively related to p‐doping as confirmed by electrochemical impedance spectroscopy analysis. Indeed, a multi‐layered architecture to decouple hole injection/transport and exciton formation enables a further 2‐fold enhanced irradiance/stability. Overall, this work illustrates that deciphering the rules for silver(I) complex design for lighting is tricky, but worthwhile. [ABSTRACT FROM AUTHOR]

The present study reports the synthesis and spectroscopic characterization of dinuclear silver(I) complexes, {[Ag(X-O)(phtz-N)]2(µ-phtz-N,N')2} (X = NO3 - (Ag1) and CF3SO3 - (Ag2), and phtz is phthalazine). The interaction of these two complexes with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was investigated to assess their binding affinity to these biomolecules. The binding constants of complexes Ag1 and Ag2 to BSA are found to be higher than those for ct-DNA, being in accordance with their higher affinity toward the studied protein. The values of partition coefficient (logP) for the investigated complexes indicate higher cellular uptake efficiency of Ag1 than Ag2. The in vivo toxicity of the complexes Ag1 and Ag2 against the model organism, Caenorhabditis elegans, was studied to check their therapeutic potential.

Ag(I) coordination compounds have recently attracted much attention as antiproliferative and antibacterial agents against a wide range of cancer cell lines and pathogens. The bioactivity potential of these complexes depends on their structural characteristics and the nature of their ligands. Herein, we present a series of four Ag(I) coordination compounds bearing as ligands the CH3-substituted thiadiazole-based thioamide 5-methyl-1,3,4-thiadiazole-2-thiol (mtdztH) and phosphines, i.e., [AgCl(mtdztH)(PPh3)2] (1), [Ag(mtdzt)(PPh3)3] (2), [AgCl(mtdztH)(xantphos)] (3), and [AgmtdztH)(dppe)(NO3)]n (4), where xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and dppe = 1,2-bis(diphenylphosphino)ethane, and the assessment of their in vitro antibacterial and anti-cancer efficiency. Among them, diphosphine-containing compounds 3 and 4 were found to exhibit broad-spectrum antibacterial activity characteristics against both Gram-(+) and Gram-(–) bacterial strains, showing high in vitro bioactivity with IC50 values as low as 4.6 μΜ. In vitro cytotoxicity studies against human ovarian, pancreatic, lung, and prostate cancer cell lines revealed the strong cytotoxic potential of 2 and 4, with IC50 values in the range of 3.1–24.0 μΜ, while 3 and 4 maintained the normal fibroblast cells' viability at relatively higher levels. Assessment of these results, in combination with those obtained for analogous Ag(I) complexes bearing similar heterocyclic thioamides, suggest the pivotal role of the substituent groups of the thioamide heterocyclic ring in the antibacterial and anti-cancer efficacy of the respective Ag(I) complexes. Compounds 1–4 exhibited moderate in vitro antioxidant capacity for free radicals scavenging, as well as reasonably strong ability to interact with calf-thymus DNA, suggesting the likely implication of these properties in their bioactivity mechanisms. Complementary insights into the possible mechanism of their anti-cancer activity were provided by molecular docking calculations, exploring their ability to bind to the overexpressed fibroblast growth factor receptor 1 (FGFR1), affecting cancer cells' functionalities. [ABSTRACT FROM AUTHOR]

Cancer is a fast-growing disease responsible for many deaths worldwide. Due to its aggressive and forever-changing nature, it is imperative to find alternative anti-cancer agents that could possibly treat this disease. Silver(I) phosphine complexes were synthesized by reaction of AgNO3, AgCl, and AgBr with cyclohexyldiphenylphosphine to produce 1:1, 1:2, or 1:3 molar ratios of new silver complexes with the formulas [Ag(PPh2Cy)NO3] (1), [Ag(PPh2Cy)2NO3] (2), [Ag(PPh2Cy)3NO3] (3), [Ag(PPh2Cy)2Cl] (4), [Ag(PPh2Cy)3Cl] (5), and [Ag(PPh2Cy)3Br] (6), respectively. The complexes were characterized by elemental analyses, FT-IR and 1H, 13C, 31P NMR spectroscopic techniques. The crystal structures of 5 (CCDC 1480482) and 6 (CCDC 2183297) were determined by single-crystal X-ray diffractometry. All six complexes were evaluated as potential anti-cancer agents in four different human malignant (SNO, MCF-7, A375, and A549) cell lines and one human non-malignant (HEK293) cell line. Overall, these complexes were significantly cytotoxic to both cancerous and non-cancerous cells and are therefore not considered suitable anti-cancer agents in their current form. [ABSTRACT FROM AUTHOR]

A series of NHC‐based selenourea Ag(I) and Au(I) complexes were evaluated for their anticancer potential in vitro, on 2D and 3D human cancer cell systems. All NHC‐based selenourea complexes possess an outstanding cytotoxic potency, which was comparable or even better than that of the reference metallodrug auranofin, and were also able to overcome both platinum‐based and multi‐drug resistances. Intriguingly, their cytotoxic potency did not correlate with solution stability, partition coefficient or cellular uptake. On the other hand, mechanistic studies in cancer cells revealed their ability to strongly and selectively inhibit the redox‐regulating enzyme Thioredoxin Reductase (TrxR), being even more effective than auranofin, a well‐known TrxR inhibitor, without affecting other redox enzymes such as Glutathione Reductase (GR). The inhibition of TrxR in H157 human cancer cells caused, in turn, the disruption of cellular thiol‐redox homeostasis and of mitochondria pathophysiology, ultimately leading to cancer cell death through apoptosis. [ABSTRACT FROM AUTHOR]

The review summarizes information about the known Ag+ solvate complexes isolated and structurally characterized as adducts and/or salts with polyoxometalates. The AgNO3/(Bu4N)4[β-Mo8O26]/N,N-dimethylformamide (DMF) system along with the complexes isolated for the first time are considered in detail: (Bu4N)4[Ag2(NO3)2Mo8O26]; (Bu4N)2n[Ag1.8(MoO2)0.2Mo8O26]n; (Bu4N)4[Ag2(DMF)4Mo8O26] [Ag2(DMF)2Mo8O26]; (Bu4N)4[Ag2(DMF)4Mo8O26][Ag2(DMF)2Mo8O26]·0.25DMF. [ABSTRACT FROM AUTHOR]

Silver(I) complex formation with thiourea (Tu), N-phenylthiourea (Phtu), N,N'-diphenylthiourea (Bphtu), N-acetylthiourea (Aсtu), and thiosemicarbazide (Tsc) in aqueous solution at temperatures in the range 278.2–328.2 K at the ionic strength I = 0.11 mol/L (0.1 NaNO3 + 0.01 HNO3) was studied potentiometrically. The reactions yield various complexes by the scheme Ag+ + iL = where i = 1–3, at = (1–5) × 10–5 mol/L. The thermodynamic characteristics (logβi, ΔrG0, ΔrH0, and ΔrS0) for these reactions were determined. The highest rise in exothermicity (ΔrH0) was observed for the second complex formation step: AgL+ + L = The exception is the reaction with thiosemicarbazide. The stabilities of monocoordinated complexes vary in the order Aсtu < Tsc < Bphtu < Phtu < Tu, in good match with the protonation constants of the respective ligands. For the and complexes of Phtu and Bphtu, this trend is spoiled because of the influence of phenyl substituents on the complex-forming properties of these thiourea derivatives. [ABSTRACT FROM AUTHOR]

A family of three‐ and four‐coordinated silver(I) complexes of formulas [Ag(PPh3)2L], [Ag(PPh3)L], and [AgL]n with N‐thiophosphorylated thiourea and thioamide ligands of general formula RC(S)NHP(S)(OPri)2 [R = Ph, PhNH, iPrNH, tBuNH, NH2] have been studied by solid‐state 109Ag and 31P CPMAS NMR spectroscopy. 109Ag NMR spectra have provided valuable structural information about Ag coordination, which is in good accordance with the available crystal structure data. The data presented in this work represent a significant addition to the available 109Ag chemical shifts and chemical shifts anisotropies. The silver chemical shift ranges for different P,S‐environments and coordination state were discussed in detail. The 1J(31P–107/109Ag) and 2J(31P–31P) values were determined and analyzed. [ABSTRACT FROM AUTHOR]

• Two silver(I) complexes with econazole were synthesized and characterized. • DFT was used for investigation of solution behaviour of the complexes. • Silver(I) complexes showed significant activity against the tested Candida species. • Silver(I) complexes reduced the amount of ergosterol in the fungal cell membrane. • Silver(I) complexes showed remarkable activity against the Staphylococcus aureus. Two new silver(I) complexes with the antifungal agent econazole (ecz) of the general formula [Ag(еcz) 2 ]X, X = CF 3 SO 3 − (Ag1) and PF 6 − (Ag2), were synthesized and structurally characterized by spectroscopic (1H NMR, IR and UV–Vis) and electrochemical methods. The crystal structure of Ag2 was determined by single crystal X-ray diffraction analysis, confirming an ideal linear geometry of the silver(I) ion in this complex. In addition, by utilising Hirshfeld surface analysis (HSA), it was verified that the crystal structure of Ag2 is stabilized by H⋯H, H⋯Cl, C⋯H, and H⋯F interactions. Density functional theory (DFT) calculations provided additional evidence for formation of the complexes in the solid state and their stability in solution. The coordination of ecz to the silver(I) ion endowed this agent with antibacterial activity against Gram-positive (Pseudomonas aeruginosa and Escherichia coli) and Gram-negative (Staphylococcus aureus and Listeria monocytogenes) bacteria. The most significant antibacterial activity of Ag1 and Ag2 was observed against S. aureus with 56- and 73-fold improvement, respectively, compared to the parent drug. Moreover, a study of the bacterial antibiofilm activity revealed that these complexes were able to prevent approximately 90 % of biofilm formation at their low concentrations. Also, both complexes have shown more pronounced anti- Candida activity than econazole itself, being less toxic on the human normal fibroblast cell line MRC-5. The total amount of ergosterol was reduced in the presence of the subinhibitory concentrations of Ag1 and Ag2 complexes, which was also confirmed by a molecular docking study with two isomers of cytochrome P450 sterol 14 α -demethylase, CYP51B and CYP130, as target receptors. Two silver(I) complexes with clinically used antifungal agent econazole have shown significantly improved anti- Staphylococcus and anti- Candida activities in comparison to organic-based drug itself, being less toxic on the human normal fibroblast cell line MRC-5. [Display omitted] [ABSTRACT FROM AUTHOR]

Recognizing that metal ions play an important role in modifying the pharmacological properties of known organic-based drugs, the present manuscript addresses the complexation of the antifungal agent voriconazole (vcz) with the biologically relevant silver(I) ion as a strategy for the development of new antimycotics. The synthesized silver(I) complexes with vcz were characterized by mass spectrometry, IR, UV–Vis and NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystallographic results showed that complexes {[Ag(vcz)(H 2 O)]CH 3 SO 3 } n (1), {[Ag(vcz) 2 ]BF 4 } n (2) and {[Ag(vcz) 2 ]PF 6 } n (3) have polymeric structures in the solid state, in which silver(I) ions have a distorted tetrahedral geometry. On the other hand, DFT calculations revealed that the investigated silver(I) complexes 1 – 3 in DMSO exist as linear [Ag(vcz- N2)(vcz- N19)]+ (1a), [Ag(vcz- N2)(vcz- N4)]+ (2a) and [Ag(vcz- N4) 2 ]+ (3a) species, respectively. The evaluated complexes showed an enhanced anti- Candida activity compared to the parent drug with minimal inhibitory concentration (MIC) values in the range of 0.02–1.05 μM. In comparison with vcz, the corresponding silver(I) complexes showed better activity in prevention hyphae and biofilm formation of C. albicans , indicating that they could be considered as promising agents against Candida that significantly inhibit its virulence. Also, these complexes are much better inhibitors of ergosterol synthesis in the cell membrane of C. albicans at the concentration of 0.5 × MIC. This is also confirmed by a molecular docking, which revealed that complexes 1a – 3a showed better inhibitory activity than vcz against the sterol 14 α -demethylase enzyme cytochrome P450 (CYP51B), which plays a crucial role in the formation of ergosterol. Considering the more favorable activity of silver(I) complexes with voriconazole compared to this antifungal agent, such complexes should be further investigated as candidates for potential use in therapy against lethal Candida infections. [Display omitted] • Three silver(I) complexes with voriconazole were synthesized and characterized. • DFT was used for determination of the structure of complexes in solution. • Silver(I) complexes showed significant anti- Candida activity. • Silver(I) complexes had the ability to prevent hyphae and biofilm formation. • Silver(I) complexes reduced the amount of ergosterol in the fungal cell membrane. [ABSTRACT FROM AUTHOR]

We investigated the anti-cancer activity of [Ag(μ-dicl)]n1 and [AgH(nif)2] 2 complexes against human cancer cell lines (MCF-7, HT-29, and HepG2) and mouse fibroblast (3T3-L1) cell line. Anti-proliferative activity was monitored by XTT cell viability and LDH leakage assays. Cell death mode was evaluated by multi-caspase activity, annexin V cytofluorimetric, MMP, cell cycle arrest, and ROS generation assays. Antioxidant capacity was evaluated on SOD, GPx, GR, and CAT enzymes. The XTT and LDH assay results showed that both complexes exhibited strong cytotoxicity against the tested cancer cell lines. The apoptotic mechanisms of the complexes were demonstrated by loss of MMP and increase in phosphatidylserine translocation, sub-G1 phase, and multi-caspase activity. Besides, both complexes induced the oxidative stress in MCF-7 cells by decreasing the activity of GPx, GR, and CAT enzymes. In conclusion, both Ag(I) complexes, especially 1, warrant for further in vivo evaluation as a new alternative in cancer treatment. Ag(I) complexes inhibited cell proliferation and induced LDH leakage in human cancer cell lines. Ag(I) complexes induced apoptosis through MMP disruption and ROS generation. Ag(I) complexes mimicked the multi-caspase activity. Ag(I) complexes increased the accumulation of sub-G1 phase. Ag(I) complexes inhibited the activity of antioxidant system enzymes. [ABSTRACT FROM AUTHOR]

Polynuclear silver(I) complex, [Ag(NO3-O)(2,2'-bq-N,N')]n, was synthesized by the reaction of equimolar amount of silver(I) nitrate and 2,2'-biquinoline (2,2'-bq) in ethanol at room temperature. The characterization of the complex was established on the basis of elemental microanalysis, IR, NMR (1H and 13C) and UV-Vis spectroscopic techniques. The results of spectroscopic analyses revealed that in [Ag(NO3-O)(2,2'-bq-N,N')]n complex, 2,2'-bq ligand behaves as a chelate, while the remaining coordination sites are occupied by the oxygen atoms of two nitrates.

Ag(I) coordination compounds have recently attracted much attention as antiproliferative and antibacterial agents against a wide range of cancer cell lines and pathogens. The bioactivity potential of these complexes depends on their structural characteristics and the nature of their ligands. Herein, we present a series of four Ag(I) coordination compounds bearing as ligands the CH3-substituted thiadiazole-based thioamide 5-methyl-1,3,4-thiadiazole-2-thiol (mtdztH) and phosphines, i.e., [AgCl(mtdztH)(PPh3)2] (1), [Ag(mtdzt)(PPh3)3] (2), [AgCl(mtdztH)(xantphos)] (3), and [AgmtdztH)(dppe)(NO3)]n (4), where xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and dppe = 1,2-bis(diphenylphosphino)ethane, and the assessment of their in vitro antibacterial and anti-cancer efficiency. Among them, diphosphine-containing compounds 3 and 4 were found to exhibit broad-spectrum antibacterial activity characteristics against both Gram-(+) and Gram-(–) bacterial strains, showing high in vitro bioactivity with IC50 values as low as 4.6 μΜ. In vitro cytotoxicity studies against human ovarian, pancreatic, lung, and prostate cancer cell lines revealed the strong cytotoxic potential of 2 and 4, with IC50 values in the range of 3.1–24.0 μΜ, while 3 and 4 maintained the normal fibroblast cells’ viability at relatively higher levels. Assessment of these results, in combination with those obtained for analogous Ag(I) complexes bearing similar heterocyclic thioamides, suggest the pivotal role of the substituent groups of the thioamide heterocyclic ring in the antibacterial and anti-cancer efficacy of the respective Ag(I) complexes. Compounds 1–4 exhibited moderate in vitro antioxidant capacity for free radicals scavenging, as well as reasonably strong ability to interact with calf-thymus DNA, suggesting the likely implication of these properties in their bioactivity mechanisms. Complementary insights into the possible mechanism of their anti-cancer activity were provided by molecular docking calculations, exploring their ability to bind to the overexpressed fibroblast growth factor receptor 1 (FGFR1), affecting cancer cells’ functionalities.

Recently, we synthesized silver(I) complex with the antifungal agent itraconazole, which showed improved anti-Candida potential and therapeutic safety in comparison to itraconazole and rescued zebrafish embryos affected by lethal C. albicans infection, when used in safe doses. Inspired by these results, in the present study, three new silver(I) complexes with clinically used azoles, econazole (ecz), clotrimazole (ctz) and voriconazole (vcz), [Ag(ecz)2]SbF6 (Ag1), [Ag(ctz)2]SbF6 (Ag2) and {[Ag(vcz)2]SbF6}n (Ag3) were synthesized and structurally characterized by elemental microanalysis, mass spectrometry, spectroscopy (1H NMR, IR and UV-Vis), cyclic voltammetry, molar conductivity measurements, and single crystal X-ray diffraction analysis. The spectroscopic and crystallographic results revealed that, in the synthesized silver(I) complexes, azole ligands are monodentately coordinated to the Ag(I) ion through the nitrogen atom forming [Ag(azole)2]+ complex cation. The antimicrobial effect of complexes and azole ligands was evaluated against different Candida species, as well as Gram-positive and Gram-negative bacteria. The synthesized complexes Ag1-3 exhibited good to moderate antimicrobial activity being, in most cases, more active than the corresponding azole ligands. Complexes Ag2 and Ag3 also showed strong inhibitory activity against C. albicans biofilm formation and strong inhibition of C. albicans filamentation at subinhibitory concentrations.

2-(4-Alkoxyphenyl)-5-(p-tolyl)-1,3,4-thiadiazoles (alkoxy: O(CH2)nH, n = 1–8) (6a–h) (as a series of 1,3,4-thiadiazole derivatives) and their silver(I) complexes: bis(2-(4-alkoxyphenyl)-5-(p-tolyl)-1,3,4-thiadiazole)-silver(I) complexes (alkoxy: O(CH2)nH, n = 1–8) (7a–h) were prepared and characterized with different techniques: microelemental analysis, FTIR, UV–Vis, 1H NMR, 13C NMR and mass (for the organic compounds) spectra, in addition to the molar conductivity measurements (for Ag(I) complexes). Liquid crystal behavior of the two series of compounds was evaluated using polarized light optical microscopy (POM). The study revealed that both series are enantiotropic liquid crystalline materials (exhibiting wide mesomorpic temperature ranges) with different behavior and properties. 6a–f displayed only nematic mesophase upon heating and cooling, while 6g and 6h exhibited both of SmC and nematic mesophases upon heating and cooling. Upon complexation of 1,3,4-thiadiazoles (6a–h) to silver(I), the liquid crystal behavior and properties are significantly changed (different mesophases, and lower mesophase and clearing temperatures). However, 7b–h exhibited SmA mesophase upon heating and cooling, while 7a shows no mesomorphic properties (simply melted to isotropic liquid). [ABSTRACT FROM AUTHOR]

Silver(I) complexes of type [Ag(X){E(CH 2 C 6 H 4 Me-2) 2 } n ] (E = S, Se; X = CF 3 SO 3 , NO 3 , ClO 4 , n = 1, 2) were prepared and structurally characterized both in solution and in solid state. The complexes with AgOTf moieties showed promising in vitro antiproliferative activity against the murine melanoma B16.F10 cells. [Display omitted] • Ag(I) complexes: [Ag(X){E(CH 2 C 6 H 4 Me-2) 2 } n ] [E = S, Se; X = OTf, NO 3 , ClO 4 ; n = 1,2] • 1:1 electrolytes in MeOH solution. • Se→Ag coordination. • supramolecular associations by O···Ag, O···H and π H···Cg secondary bonding. • In vitro antiproliferative activity against murine melanoma B16.F10 cells. Silver(I) complexes of types [Ag(X){E(CH 2 C 6 H 4 Me-2) 2 }] [E = S, X = CF 3 SO 3 (1), NO 3 (2), ClO 4 (3); E = Se, X = CF 3 SO 3 (4), NO 3 (5), ClO 4 (6)] and [Ag(X){E(CH 2 C 6 H 4 Me-2) 2 } 2 ] [X = CF 3 SO 3 , E = S (7), Se (8); X = ClO 4 , E = S (9), Se (10)] were prepared by reacting the diorganochalcogenides (2-MeC 6 H 4 CH 2) 2 E [E = S (L1), Se (L2)] with the appropriate silver(I) salt in a 1:1 and a 2:1 molar ratio, respectively. The ligands and the Ag(I) complexes were characterized by multinuclear NMR spectroscopy (1H, 13C{1H}, 19F{1H}, 77Se{1H}, as appropriate), ESI+ mass spectrometry, elemental analysis and IR spectroscopy. The crystal and molecular structures of the ligand L1 and the complexes 2 , 5 , 7 , 8 and 9 were determined by single-crystal X-ray diffraction. The molar conductivity of the reported metal complexes showed their behaviour as 1:1 electrolytes in solution, while in solid state the inorganic anionic ligand is coordinated to silver by O Ag bonds. Preliminary results showed that the silver(I) complexes bearing triflato ligands have in vitro promising antiproliferative activity against the murine melanoma B16.F10 cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mononuclear silver(I) complexes based on cyclic arsines were synthesized. • Structure of the complexes were elucidated by spectral methods and X-ray diffraction. • Ag(I) complexes were evaluated for their in vitro cytotoxicity against M−HeLa and HuTu80 cells. • Ag(I) complexes were tested on the antimicrobial activity against both Gram-positive and Gram-negative bacteria and fungi. Silver(I) complexes containing cyclic arsine ligands, namely 10-arylphenoxarsines L1 – L4 and 10-phenyl-5,10-dihydrophenarsazine L5 , have been synthesized by the reactions of AgBF 4 with the cyclic arsine ligands in different molar ratios. All complexes are characterized by 1H NMR, mass-spectrometry, elemental analysis, and X-ray diffraction. All complexes exhibit moderate to enhanced antimicrobial activity against both Gram-positive and Gram-negative bacteria, fungi as well as anticancer activity against M−HeLa and HuTu 80 cell lines. [ABSTRACT FROM AUTHOR]

New polynuclear silver(I) complexes, [Ag(CF3SO3)(4,7-phen)(CH3CN)]n (1) and [Ag(PO2F2)(4,7-phen)]n (2), were synthesized by the reaction of 4,7-phenanthroline (4,7-phen) and the corresponding AgX salt (X = CF3SO3 - and PF6 -) in 1:2 mole ratio, respectively, in methanol/acetone (1:1 volume ratio) at room temperature. The characterization of the complexes was established on the basis of elemental microanalysis, IR and NMR (1H and 13C) spectroscopic techniques, while their crystal structures were determined by single-crystal X-ray diffraction analysis. The results of spectroscopic and crystallographic analyses revealed that in these complexes, 4,7-phen behaves as a bridging ligand between two metal ions, while the remaining coordination sites of the Ag(I) ions are occupied by the oxygen atom of CF3SO3 - and an acetonitrile nitrogen atom in 1 or by two oxygen atoms from two PO2F2 -, formed after hydrolysis of PF6 -, in 2. In the solid state, both complexes are coordination polymers in which the geometry around the Ag(I) ions is distorted tetrahedral. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172036]

Tetra‐armed cyclen (1) bearing two 4‐(4′‐pyridyl)benzyl and two 3,5‐difluorobenzyl groups and its Ag+ complexes were prepared and structurally characterized. The complexes formed between 1 and Ag+ undergoes a reversible structural transformation between a 2:2 dimeric complex and a 3:5 pentacyclic trefoil complex with changes in the Ag+/1 molar ratio. It was also revealed that the 3:5 trefoil complex could encapsulate benzene and [D6]benzene selectively in solid‐state. The benzene‐included structures are stabilized by C−H⋅⋅⋅F−C interactions between the benzene molecule and the ligand molecule. [ABSTRACT FROM AUTHOR]

In this work, three novel silver(I) complexes with an almost completely rigid and bulky monodentate ligand, 1-adamantanamine, were synthesized. The aliphatic amine, 1-adamantanamine, is the sole electron donor ligand in these complexes. In addition to spectroscopic characterization, the basic biological activities of the new compounds were investigated and their minimum inhibitory concentrations were determined. The antifungal and antibacterial activities indicate that these compounds could potentially be applied as new therapeutics. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172017, Grant no. 172035 and Grant no. III 43004]

Three silver(I) dipeptide complexes [Ag(GlyGly)]n(NO3)n (AgGlyGly), [Ag2(GlyAla)(NO3)2]n (AgGlyAla) and [Ag2(HGlyAsp)(NO3)]n (AgGlyAsp) were prepared, investigated and characterized by vibrational spectroscopy (mid-IR), elemental and thermogravimetric analysis and mass spectrometry. For AgGlyGly, X-ray crystallography was also performed. Their stability in biological testing media was verified by time-dependent NMR measurements. Their in vitro antimicrobial activity was evaluated against selected pathogenic microorganisms. Moreover, the influence of silver(I) dipeptide complexes on microbial film formation was described. Further, the cytotoxicity of the complexes against selected cancer cells (BLM, MDA-MB-231, HeLa, HCT116, MCF-7 and Jurkat) and fibroblasts (BJ-5ta) using a colorimetric MTS assay was tested, and the selectivity index (SI) was identified. The mechanism of action of Ag(I) dipeptide complexes was elucidated and discussed by the study in terms of their binding affinity toward the CT DNA, the ability to cleave the DNA and the ability to influence numbers of cells within each cell cycle phase. The new silver(I) dipeptide complexes are able to bind into DNA by noncovalent interaction, and the topoisomerase I inhibition study showed that the studied complexes inhibit its activity at a concentration of 15 μM.

Three new silver(I) complexes [Ag(NO3)(tia)(H2O)]n (Ag1), [Ag(CF3SO3)(1,8-naph)]n (Ag2) and [Ag2(1,8-naph)2(H2O)1.2](PF6)2 (Ag3), where tia is thianthrene and 1,8-naph is 1,8-naphthyridine, were synthesized and structurally characterized by different spectroscopic and electrochemical methods and their crystal structures were determined by single-crystal X-ray diffraction analysis. Their antimicrobial potential was evaluated against four bacterial and three Candida species, and the obtained results revealed that these complexes showed significant activity toward the Gram-positive Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa and the investigated Candida species with minimal inhibitory concentration (MIC) values in the range 1.56–7.81 μg/mL. On the other hand, tia and 1,8-naph ligands were not active against the investigated strains, suggesting that their complexation with Ag(I) ion results in the formation of antimicrobial compounds. Moreover, low toxicity of the complexes was detected by in vivo model Caenorhabditis elegans. The interaction of the complexes with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) was studied to evaluate their binding affinity towards these biomolecules for possible insights into the mode of antimicrobial activity. The binding affinity of Ag1–3 to BSA was higher than that for DNA, indicating that proteins could be more favorable binding sites for these complexes in comparison to the nucleic acids.

Self‐assembly of AgClO4 with 1,2,3‐tris(isonicotinoyloxy)benzene (L) in a mixture of ethanol and acetone in a 1:1 volume ratio in refrigerator afforded concomitantly two kinds of thin‐ and block‐shaped colorless crystals consisting of {[Ag(L)]ClO4·0.5CH3CH2OH}n and {[Ag(L)]ClO4·0.5CH3CH2OH·2Me2CO}n, respectively, in a 3:2 ratio. By contrast, self‐assembly at room temperature yielded thin crystals exclusively. At 5 °C, in particular, the self‐assembly in 3:1 and 1:2 ethanol/acetone solutions yielded thin‐ and block‐shaped crystals, respectively, suggesting that discrimination of the two products can be controlled by the solvent volume ratio and crystallization temperature. The products' crystal structures and physicochemical properties were fully characterized by means of single‐crystal X‐ray diffraction measurement, thermal analysis, and infrared (IR) data. [ABSTRACT FROM AUTHOR]

A heteroleptic silver(I) complex of bis(diphenylphosphano)methane (DPPM) and thiourea (tu) with the formula [Ag2(DPPM)2(tu)3](NO3)2 · 2H2O (1) was prepared and characterized by infrared (IR) and nuclear magnetic resonance (1H, 13C, and 31P) spectroscopic methods, and X-ray crystallography. The crystal structure determination has shown that the complex (1) is dinuclear having each silver(I) ion coordinated by two phosphorus atoms of DPPM molecules and two sulfur atoms of tu ligands adopting a distorted tetrahedral environment. The two silver atoms are bridged by one of the three tu molecules. The other two tu ligands are coordinated in a terminal mode; one with each silver(I) ion. The dinuclear units are associated to each other through hydrogen bonding interactions to form a three-dimensional network in the solid state. Complex 1 showed significant activity against two Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and molds (Aspergillus niger, Penicillium citrinum), while the activities were poor towards yeasts (Candida albicans, Saccharomyces cerevisiae). [ABSTRACT FROM AUTHOR]

Five novel silver(I) complexes with 4,7-phenanthroline (4,7-phen), [Ag(NO 3 - O)(4,7-phen- μ - N4 , N7)] n (1), [Ag(ClO 4 - О)(4,7-phen- μ - N4 , N7)] n (2), [Ag(CF 3 COO- O)(4,7-phen- μ - N4 , N7)] n (3), [Ag 2 (H 2 O) 0.58 (4,7-phen) 3 ](SbF 6) 2 (4) and {[Ag 2 (H 2 O)(4,7-phen- μ - N4 , N7) 2 ](BF 4) 2 } n (5) were synthesized, structurally elucidated and biologically evaluated. These complexes showed selectivity towards Candida spp. in comparison to the tested bacteria and effectively inhibited the growth of four different Candida species, particularly of C. albicans strains, with minimal inhibitory concentrations (MICs) in the range of 2.0–10.0 μM. In order to evaluate the therapeutic potential of 1–5 , in vivo toxicity studies were conducted in the zebrafish model. Based on the favorable therapeutic profiles, complexes 1 , 3 and 5 were selected for the evaluation of their antifungal efficacy in vivo using the zebrafish model of lethal disseminated candidiasis. Complexes 1 and 3 efficiently controlled and prevented fungal filamentation even at sub-MIC doses, while drastically increased the survival of the infected embryos. Moreover, at the MIC doses, both complexes totally prevented C. albicans filamentation and rescued almost all infected fish of the fatal infection outcome. On the other side, complex 5 , which demonstrated the highest antifungal activity in vitro , affected the neutrophils occurrence of the infected host, failed to inhibit the C. albicans cells filamentation and showed a poor potential to cure candidal infection, highlighting the importance of the in vivo activity evaluation early in the therapeutic design and development process. The mechanism of action of the investigated silver(I) complexes was related to the induction of reactive oxygen species (ROS) response in C. albicans , with DNA being one of the possible target biomolecules. Silver(I) complexes with 4,7-phenanthroline can be consider as novel potent metal-based antifungal compounds with possible application in antifungal therapy against lethal Candida albicans infection. Unlabelled Image • Five silver(I) complexes with 4,7-phenanthroline were synthesized and characterized. • Silver(I) complexes show significant and selective anti- Candida activity. • Silver(I) complexes rescued the zebrafish embryos of lethal Candida albicans infection. • Silver(I) complexes reduced the fungal burden by preventing fungal filamentation. • The mechanism of antifungal action of the silver(I) complexes is multifaceted. [ABSTRACT FROM AUTHOR]

Abstract Three silver(I) complexes bearing different combinations of diphosphanes and N-heterocyclic thioamides or thioamidates as ligands have been synthesized and structurally characterized: the ionic, homoleptic compound [Ag(xantphos) 2 ][BF 4 ] (1), where xantphos = 4,5-bis(diphenylphosphano)-9,9-dimethyl-xanthene, and the neutral, heteroleptic compounds [Ag(xantphos)(κ-S-pymt)] (2), where pymt = pyrimidine-2-thiolate, and [AgCl(dppbz)(κ-S-mtdztH)] (3), where dppbz = bis(diphenylphosphano)benzene and mtdztH = 5-methyl-1,3,4-thiadiazole-2-thione. X-ray crystallography studies reveal tetrahedral coordination environments around the silver(I) ions in compounds 1 and 3 , while a trigonal planar arrangement of the P 2 S donor set has been found around the metal center in compound 2. The interaction of the three compounds with calf-thymus DNA was monitored by UV–vis spectroscopy, DNA-viscosity measurements and indirectly by testing their ability to compete with ethidium bromide for DNA intercalation sites studied by fluorescence emission spectroscopy. Intercalation was revealed as the most possible binding mode for the neutral compounds 2 and 3 and electrostatic interactions for the cationic complex [Ag(xantphos) 2 ]+ in 1. Complexes 1 – 3 have also been found to display moderate in vitro antibacterial activity against the Gram-positive B. cereus , S. aureus and the Gram-negative E. coli bacterial strains, with the homoleptic bis-phosphane silver(I) compound 1 exhibiting a lower activity than the other two neutral compounds. Graphical abstract Cationic homoleptic and neutral heteroleptic silver(I) complexes bearing different combinations of a diphosphane and a N-heterocyclic thioamide or thioamidate ligands have been synthesized and structurally characterized. Their CT DNA binding affinity and antibacterial activity have been studied. Unlabelled Image Highlights • Cationic homoleptic silver(I) complex with diphosphanes • Neutral diphosphane/thioamide silver(I) complexes • Electrostatic DNA interaction for cationic and intercalation for neutral complexes • Cationic complex shows lower antibacterial activity. [ABSTRACT FROM AUTHOR]

The 4-aryl substituted pyrazolate ligands, L1(Ph)H and L1(Naph)H, were synthesized by Suzuki-Miyaura cross-coupling and combined with metal sources to give cyclic trinuclear structures [AgL1(Ph)]3, [AuL1(Ph)]3, [AgL1(Naph)]3, and [AuL1(Naph)]3. The aryl group determined the crystal packing of these cyclic trinuclear complexes with the phenyl systems exhibiting stair type solid state structures and the naphthyl complexes exhibiting irregular structures with spaces occupied with some solvent molecules. These differences in solid-state structures were accompanied by differences in M-N stretching frequencies and temperature dependent photoluminescence. [ABSTRACT FROM AUTHOR]

New double-armed crown ether ligands linked to pyridine derivatives have been synthesized and characterized. These macrocyclic ligands (1-5) have been synthesized by the reactions of 4′,5′-bis(bromomethyl)benzo-15-crown-5 with 3-hydroxy pyridine derivatives. A series of Na+, K+ and Ag+ complexes (1a-5a, 1b-5b and 1c-5c) of the macrocyclic ligands have been prepared from sodium perchlorate, sodium picrate, potassium iodide, potassium picrate and silver nitrate salts, respectively. The most suitable cation Na+ is bound to the 15-crown-5 cavity and 1:1 "filling complexes" are formed (1a-5a) while the K+ cation interacts with the crown ether cavity and forms sandwich-type complexes (1b-5b). The Ag+ complexes (1c-5c) have been obtained with a pyridine moiety of the new crown ethers. New ligands undergo photophysical changes when bonding the cation. The influence of metal cations such as Na+, Li+, K+, Fe3+, Cu2+, Ca2+, Ba2+ and Al3+ on the spectroscopic properties of the pyridine linked to the double-armed crown ether moiety was investigated in EtOH solution by means of absorption and emission spectrometry. The prepared compounds (1-5, 1a-5a, 1b-5b and 1c-5c) were evaluated for antibacterial and antifungal activities against pathogenic microorganisms. The results show that the antimicrobial activity of the synthesized compounds varying a degree of inhibitory effects on the growth of different tested pathogenic strains. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ag+ complex with 1a interacts with CH 3 CN molecules at both the (CN) of CH 3 CN and the CH(sp 2) of the aromatic side-arms in the solid state. • The DFT calculations revealed electron donation from the CH(sp 2) of the styrylmethyl group to the C(sp) and N(sp) atoms of acetonitrile. • The CH(sp 2)··· π(C≡N) interaction observed in this study represents the first experimental example. New tetra-armed cyclens (1a and 1b) with two 4-fluorobenzyl and two styrylmethyl groups have been synthesized. The structures of their silver(I) complexes have been studied using 1H NMR titration experiments and X-ray crystallography. The results showed that these ligands are argentivorous molecules. However, the pseudo -cavities do not have sufficient space to include organic guests such as acetonitrile. The pseudo -cavities are not stable enough due to weak CH··· π interactions between the benzyl groups and the styrylmethyl groups. The binding constants for these ligands with silver(I) ions decrease with decreasing electron density of the aromatic side-arms. These findings indicate that CH··· π interactions play a crucial role in maintaining stable pseudo -cavities in the argetivorous molecules. The AgX (X = BF 4 , PF 6 , and OTf) complexes with 1a were prepared in the presence of acetonitrile. X-ray crystallography of these complexes revealed that AgX (X = PF 6 and OTf) complexes with 1a form inclusion complexes with acetonitrile. The C≡N moiety of acetonitrile mainly interacts with the hydrogen atoms in the styrylmethyl side-arms through C(sp 2)-H··· π (C≡N) interaction, with CH···N(C≡N) and CH···C(C≡N) distances of approximately 2.63–2.75 and 2.69–3.15 Å, respectively. DFT calculations suggest that the C(sp 2)-H··· π interaction may be due to the electron donation from C(sp 2)-H of the styrylmethyl side-arms to the π (C≡N) of acetonitrile. [ABSTRACT FROM AUTHOR]

Redox-active azothioformamides (ATFs) contain an NNCS 1,3-heterodiene motif typically found in other molecular subclasses that exhibit a wide range of cytotoxic and anti-neoplastic effects, either alone or as chelation complexes with various metals. For this study, a small library of ATF compounds was synthesized and tested across a range of microbes, fungi, and cancer cell lines for biological activity, both alone and as metal chelates of copper(I) and silver(I) salts. Alone, the ATF compounds exhibited little antimicrobial activity, but all inhibited the cell growth of A549 lung carcinoma cells (IC 50 values of 1–6 μM). As copper(I) and silver(I) coordination complexes, several of the ATFs showed antimicrobial activity against gram positive Staphylococcus aureus and Bacillus subtilis cells (IC 50 ∼ 5–20 μM) and the fungi Candida albicans (IC 50 ∼ 8–12 μM); as well as cytotoxicity against both lung carcinoma A549 cells and lymphoblastic leukemia K562 cells. Azothioformamides and copper(I) and silver(I) metal coordination complexes were prepared and tested for various antimicrobial activity including against MRSA (strain BAA-44) cells. [Display omitted] • Preliminary investigation of a small library of azothioformamide for biological activity. • Inhibition (≤ 6 μM IC 50) of human lung adenocarcinoma cells across the entire library. • Copper(I) azothioformamide complexes were uniformly active against a human chronic myelogenous leukemia cell line. • Silver(I) azothioformamide complexes with electron withdrawing groups provide strong overall antiproliferative properties. [ABSTRACT FROM AUTHOR]

Two silver(I) complexes with biologically relevant heterocyclic ligands, pyrrole and furan-2- carboxylic acid, were synthesized and their composition was confirmed using elemental, spectral, thermal and structural analyses. The {[Ag(Py2c)]} n (AgPy2c, Py2c = pyrrole-2-carboxylate) and {[Ag(Fu2c)]} n (AgFu2c, Fu2c = furan-2-carboxylate) solubility and stability in biological test stock solution were confirmed by 1H NMR spectroscopy. The X-ray analysis has enabled us to determine typical argentophilic interactions and bridging carboxylate coordination mode of both ligands. Potentiometric data analysis by BSTAC program resulted in the determination of the stability constant of only one species, i.e., the ML (M = Ag+, L = Fu2c−), log β ML = 0.59 ± 0.04. Antimicrobial and anticancer tests were performed against selected microorganisms and cell lines with new silver(I) complexes and compared with AgSD (silver(I) sulfadiazine) and cisplatin. From their microbial toxicity point of view, selectivity was determined against lactobacilli (AgPy2c is 8× more effective against S. aureus and E. coli and AgFu2c is 8× more effective against E. coli and 4× against S. aureus). AgFu2c significant anticancer activity was determined against Jurkat cell lines (IC 50 = 8.00 μM) and was similar to cisPt (IC 50 = 6.3 μM) similarly to its selectivity (SI (AgFu2c) = 7.3, SI (cisPt) = 6.4, SI = selectivity index). In addition, cell cycle arrest was observed already in the Sub-G0 phase during a flow cytometry experiment. To evaluate the AgPy2c and AgFu2c bioavailability we also discuss their Lipinski's Rule of Five. X-ray diffraction and IR spectra confirmed silver(I) complexes composition. Both complexes are bacterially selective and AgFu2c complex is active against the human leukaemic T cell lymphoma (Jurkat) with similar cytotoxic effect as cisPt. All Lipinski ROF parameters point to the biological potential of the new silver(I) complexes. [Display omitted] • Two silver(I) complexes with pyrrole- and furan-2-carboxylate ligands have been synthesized and characterized. • Antimicrobial selective inhibitory properties for both complexes were observed. • The anticancer effect of the AgFu2c complex against the human leukaemic T cell lymphoma (Jurkat) is comparable to cisPt. • The studied complexes do not break a single Lipinski Rule of Five and are feasible for successful ADMET studies. [ABSTRACT FROM AUTHOR]

A series of neutral mixed-ligand [HB(pz)3]Ag(PR3) silver(I) complexes (PR3 = tertiary phosphine, [HB(pz)3]− = tris(pyrazolyl)borate anion), and the corresponding homoleptic [Ag(PR3)4]BF4 compounds have been synthesized and fully characterized. Silver compounds were screened for their antiproliferative activities against a wide panel of human cancer cells derived from solid tumors and endowed with different platinum drug sensitivity. Mixed-ligand complexes were generally more effective than the corresponding homoleptic derivatives, but the most active compounds were [HB(pz)3]Ag(PPh3) (5) and [Ag(PPh3)4]BF4 (10), both comprising the lipophilic PPh3 phosphine ligand. Detailed mechanistic studies revealed that both homoleptic and heteroleptic silver complexes strongly and selectively inhibit the selenoenzyme thioredoxin reductase both as isolated enzyme and in human ovarian cancer cells (half inhibition concentration values in the nanomolar range) causing the disruption of cellular thiol-redox homeostasis, and leading to apoptotic cell death. Moreover, for heteroleptic Ag(I) derivatives, an additional ability to damage nuclear DNA has been detected. These results confirm the importance of the type of silver ion coordinating ligands in affecting the biological behavior of the overall corresponding silver complexes, besides in terms of hydrophilic–lipophilic balance, also in terms of biological mechanism of action, such as interaction with DNA and/or thioredoxin reductase.

A convenient one-pot synthesis of diphenyl(pyrazin-2-yl)phosphine has been developed based on reaction of Ph 3 P with metallic lithium followed by treatment of the Ph 2 PLi formed with 2-chloropyrazine. The AgI, AuI and PtII chloride complexes derived from this phosphine have been synthesized and structurally characterized. [ABSTRACT FROM AUTHOR]

Graphical abstract Reactions of diphosphine and diimine ligands with AgCF 3 SO 3 under different reaction conditions gave rise to six complexes with different structures. The representative one-dimensional coordination polymer {[Ag(dppe)(dmp)](CF 3 SO 3)·(CH 3 OH)·(H 2 O)} n exhibited good stability and excellent catalytic activity toward the photodegradation of a spectrum of common organic dyes in water under UV light irradiation. Abstract Six new silver(I) complexes with diphosphine ligands and 1,10-phenanthroline derivatives are named by [Ag 2 (dppe)(dicnq) 2 ](CF 3 SO 3) 2 (1), [Ag 2 (dppp) 2 (dicnq) 2 ](CF 3 SO 3) 2 (2), [Ag 2 (dppb) 2 (dicnq) 2 ](CF 3 SO 3) 2 (3), [Ag(DPEphos)(dicnq)]CF 3 SO 3 (4), {[Ag(dppe)(dmp)](CF 3 SO 3)·(CH 3 OH)·(H 2 O)} n (5), [Ag 2 (dppp) 2 (dmp) 2 ](CF 3 SO 3) 2 ·(H 2 O) (6), (dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, DPEphos = bis[2-(diphenylphosphanyl)phenyl]ether, dmp = 2,9-dimethyl-1,10-phenanthroline, dicnq = 6,7-dicyanodipyridoquinoxaline) were characterized by IR and X-ray diffraction. Further fluorescence spectroscopy, photocatalytic properties and terahertz time-domain spectra (THz-TDS) were performed on 2 – 6. Complexes 1 – 3 and 6 were binuclear, while 4 was mononuclear. Complex 5 was a coordination polymer, displaying a one-dimensional infinite chain. Moreover, complexes 1 , 2 and 4 were assembled via several pairs of C H⋯π interactions to 1D–3D supramolecular architectures. The emission peaks of the complexes 2 – 4 all exhibit a large degree of red shift, which may be tentatively attributed to the intraligand transition. Compounds 2 – 6 represented the first examples of Ag(I) complexes bearing both diphosphine and diimine ligands that exhibit high, efficient photocatalytic abilities for dye degradation under UV light and show good stability toward photocatalysis. [ABSTRACT FROM AUTHOR]

Graphical abstract 1-Benzyl-1 H -tetrazoles were used as ligands for the synthesis of silver(I) complexes which have shown remarkable antimicrobial activity against the different fungal and bacterial strains and good therapeutic potential. Abstract Herein, we report the synthesis and structural characteristics of three tetrazole-containing compounds, 1-benzyl-1 H -tetrazole (bntz), 1-benzyl-1 H -tetrazol-5-amine (bntza) and 1-(4-methoxybenzyl)-1 H -tetrazol-5-amine (mbntza) and the corresponding silver(I) complexes of the general formula [Ag(NO 3 - O)(L- N4) 2 ] n , L = bntz (1), bntza (2) and mbntza (3). Silver(I) complexes 1 – 3 and 1-benzyl-1 H -tetrazoles have been studied in detail by NMR, IR and UV–Vis spectroscopic methods and the structures of 1 and 2 have been determined by single-crystal X-ray diffraction analysis. The results of these analyses revealed a monodentate coordination of the ligands to Ag(I) ion via the N4 tetrazole nitrogen. The antimicrobial potential of silver(I) complexes 1 – 3 was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and fungi, displaying their remarkable inhibiting activity with MIC (minimal inhibitory concentration) values in the range 2–8 and 0.16–1.25 μg/mL (3.8–16.3 and 0.31–2.15 μM), respectively. On the other hand, 1-benzyl-1 H -tetrazoles used for the synthesis of the silver(I) complexes were not active against the investigated strains, suggesting that the activity of the complexes originates from the Ag(I) ion exclusively. Moreover, silver(I) complexes 1 – 3 have good therapeutic potential, which can be deduced from their moderate cytotoxicity on the human fibroblast cell line MRC5, with IC 50 values falling in the range 30–60 μg/mL (57.7–103.4 μM). [ABSTRACT FROM AUTHOR]

Six new Ag(I) coordination complexes, namely [Ag 4 (μ-dicl) 4 (2-pic) 3 ] 1 , [Ag 2 (μ-mef) 2 (2-pic) 2 ] 2 , [Ag 2 (μ-dicl) 2 (3-pic) 2 ] 3 , [Ag 2 (μ-mef) 2 (3-pic) 2 ] 4 , [Ag 2 (μ-dicl) 2 (4-pic) 2 ] 5 and [Ag 2 (μ-mef) 2 (4-pic) 2 ] 6 , were synthesized and characterized by elemental analysis, FT-IR and thermal analysis techniques. The crystal structures of 1 , 3 , 4 and 5 were determined by X-ray diffraction analysis, whereas 2 and 6 were obtained as microcrystalline powders. X-ray diffraction analysis demonstrated that 1 occurs as a tetranuclear complex, while 3 , 4 and 5 have binuclear structures. A short Ag⋯Ag distances of 2.8446 and 2.8823 Å for 1 , 2.8409 Å for 3 , 2.8942 Å for 4 and 2.8423 Å for 5 were found in the complexes, indicating that argentophilic interactions exist between the silver ions. In 1 , the dicl ligands act as μ 3 -O,O′,O′ bridging ligands between three Ag(I) ions. In 3 , 4 and 5 , the dicl and mef ligands behave as bridging ligands and bind two Ag(I) ions together with the carboxylato oxygen atoms. The simultaneous TG/DTG and DTA techniques were applied to interpret the mass losses, decomposition temperatures and corresponding processes of the thermal behaviours of the complexes. The experimental and calculated mass losses of the proposed structures for complexes 2 and 6 are quite compatible with each other and these complexes have very similar FT-IR spectra to the other complexes, which reflect their same structural geometries and characteristics. The cytotoxic activities of the complexes ( 1 – 6 ) were tested against three different cancer cell lines, MCF-7, HT-29 and HepG2, and one normal cell line, 3 T3-L1. XTT assay results demonstrated that although all the silver(I) complexes showed good cytotoxic activity, depending on the cell types tested, the complexes with mefanamic acid ( 2 , 4 and 6 ) were found to predominate over those with diclofenac ( 1 , 3 and 5 ), as well as the superiority of 3-picoline to 4-picoline and 2-picoline. Moreover, compared with the cytotoxic potential of carboplatin, 4 especially exhibited a significant cancer cell inhibitory rate and lower cytotoxicity toward the normal cell line, with much higher selectivity indexes. [ABSTRACT FROM AUTHOR]

The following organic and organic-inorganic hybrid compounds were prepared as photo-luminescent materials following efficient and practical synthetic methods: 1,3-bis[4-(n-alkoxy)phenyl]-2-propen-1-one (where, n-alkoxy: O(CH2)nH, n = 6,7,8,9 or 10); 3,5-bis[4-(n-alkoxy)phenyl]-1H-pyrazole (where, n-alkoxy: O(CH2)nH, n = 6,7,8,9 or 10) (in case of n = 7, a mixture of 3,5-bis(4-heptyloxyphenyl)-1H-pyrazole and 3,5-bis(4-heptyloxyphenyl)-4H-pyrazole was detected) and bis(3,5-bis [4-(n-alkoxy) phenyl]-1H-pyrazole) silver(I) nitrate (where, n-alkoxy: O(CH2)nH, n = 6,7,8,9 or 10). The prepared compounds have been characterised and their structures were elucidated depending upon (FTIR, UV-Vis, 1HNMR, 13CNMR, 2D 1H-1H-COSY, 2D 1H-13C-HSQC and mass spectra) in addition to molar conductivity measurements for silver(I) complexes. The mesomorphism behaviour of the prepared compounds was studied using polarised light optical microscopy and confirmed with differential scanning calorimetry and X-ray powder diffraction techniques. The studies showed that among all of these compounds only the pyrazole derivatives are liquid crystal materials. The luminescent properties of all the prepared compounds were also investigated which confirmed that all of these compounds are photo-luminescent in the crystalline solid state and in the mesophase. [ABSTRACT FROM AUTHOR]

Mononuclear silver(I) complexes with 1,7-phenanthroline (1,7-phen), [Ag(NO 3 - O,O′ ) (1,7-phen- N7 ) 2 ] ( 1 ) and [Ag(1,7-phen- N7 ) 2 ]X, X = ClO 4 − ( 2 ), CF 3 SO 3 − ( 3 ), BF 4 − ( 4 ) and SbF 6 − ( 5 ) were synthesized and structurally characterized by NMR ( 1 H and 13 C), IR and UV–Vis spectroscopy and ESI mass spectrometry. The crystal structures of 1, 3 and 4 were determined by single-crystal X-ray diffraction analysis. In all these complexes, 1,7-phen coordinates to the Ag(I) ion in a monodentate fashion via the less sterically hindered N7 nitrogen atom. The investigation of the solution stability of 1 – 5 in DMSO revealed that they are sufficiently stable in this solvent at room temperature. Complexes 1 – 5 showed selectivity towards Candida spp. in comparison to bacteria, effectively inhibiting the growth of four different Candida species with minimal inhibitory concentrations (MIC) between 1.2 and 11.3 μM. Based on the lowest MIC values and the lowest cytotoxicity against healthy human fibroblasts with selectivity index of more than 30, the antifungal potential was examined in detail for the complex 1 . It had the ability to attenuate C. albicans virulence and to reduce epithelial cell damage in the cell infection model. Induction of reactive oxygen species (ROS) response has been detected in C. albicans , with fungal DNA being one of the possible target biomolecules. The toxicity profile of 1 in the zebrafish model ( Danio rerio ) revealed improved safety and activity in comparison to that of clinically utilized silver(I) sulfadiazine. [ABSTRACT FROM AUTHOR]

The known metallotherapeutic [Ag(salH)] 2 ( AGSAL-1 ) of salicylic acid (salH 2 ), was used for the development of new efficient silver based material for wounds healing. AGSAL-1 was characterized by spectroscopic techniques and X-ray crystallography. The wound healing epithelialization of AGSAL-1 was investigated by the means of scratch assay against immortalized human keratinocytes (HaCaT) cells. The anti-inflammatory activity of AGSAL-1 was evaluated by monitoring the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX). The antibacterial activity of AGSAL-1 was evaluated against bacterial species which colonize wounds, such as: Pseudomonas aeruginosa ( PAO1 ), Staphylococcus epidermidis and Staphylococcus aureus , by the means of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and their Inhibition Zone (IZ). Moreover, the influence of AGSAL-1 against the formation of biofilm of PAO1 and St. aureus was also evaluated by the mean of Biofilm Elimination Concentration (ΒΕC). A hydrogel material CMC@AGSAL-1 , based on the dispersion of AGSAL-1 in to carboxymethyl cellulose (CMC) was tested for its antimicrobial activity. Molecular Docking was performed, to explore the molecular interaction of AGSAL-1 with (i) the transcriptional regulator of PAO1 , LasR. (ii) the mevalonate pathway for the biosynthesis of isoprenoids which is essential for gram-positive bacteria St. epidermidis and St. aureus . The toxicity of AGSAL-1 was examined against the HaCaT cells. Its genotoxicity was evaluated using Allium cepa model, in vivo . No genotoxicity was detected, indicating that AGSAL-1 is a candidate towards the development on a new efficient medication of the silver based metallodrugs. [ABSTRACT FROM AUTHOR]

Complexes [Ag(H2-2,6AcPh)]NO 3 ( 1 ), [Ag(H2-2,6Ac p CH 3 Ph)]NO 3 ( 2 ), [Ag(H2-2,6Ac p ClPh)]NO 3 ·2H 2 O ( 3 ) and [Ag(H2-2,6Ac p NO 2 Ph)]NO 3 ( 4 ) were obtained with 2,6-diacetylpyridine bis (benzoylhydrazone) (H2-2,6AcPh) and its bis ( para -methylbenzoylhydrazone) (H2-2,6Ac p CH 3 Ph), bis ( para -chlorobenzoylhydrazone) (H2-2,6Ac p ClPh), and bis ( para -nitrobenzoylhydrazone) (H2-2,6Ac p NO 2 Ph) derivatives. Complexes ( 1 – 4 ) were characterized by microanalyses, molar conductivities, and by means of their infrared and NMR spectra. The crystal structures of ( 2 ) and ( 3 ) were determined. The bis (benzoylhydazones) were inactive or poorly active against yeast and filamentous fungal strains. In several cases the antimicrobial activity increased upon coordination to silver(I). While the parent ligand revealed to be inactive, complex ( 2 ) proved to be as active as miconazole nitrate against Candida albicans . Although the bis (benzoylhydrazones) showed no antifungal activity, complex ( 1 ) proved to be as active as nystatin against Penicillium citrinium . In addition, complexes ( 1 ) and ( 2 ) proved to be as or more effective than nystatin against Aspergillus parasiticus. The silver(I) complexes strongly interact with calf thymus DNA by an intercalative mode. [ABSTRACT FROM AUTHOR]