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A set of three new Ru(ii) polypyridyl complexes decorated with 5-aryl tetrazolato ligands (R-CN4)-, (D series, namely D1, D3 and D4), is presented herein. Whereas complex D1 represents the pyrazinyl tetrazolato analogue of a previously reported Ru(ii) complex (D2) with the general formula cis-[(dcbpy)2Ru(N^N)]+, in which dcbpy is 2,2′-bipyridine-4,4′-dicarboxylic acid and N^N is the chelating 2-pyridyl tetrazolato anion, the design of the unprecedented Ru(ii) species D3 and D4 relied upon a completely different architecture. More specifically, the molecular structure of thiocyanate-based species cis-[(dcbpy)2Ru(NCS)2], that is typically found in benchmark Ru(ii) dyes for dye sensitized solar cell (DSSCs), was modified with the replacement of two of the -NCS ligands in favour of the introduction of 5-aryl tetrazolato anions, such as the deprotonated form of 5-(4-bromophenyl)-1H-tetrazole, for complex D3 and 5-(4-cyanophenyl)-1H-tetrazole in the case of complex D4. To streamline the behavior of the D series of Ru(ii) complexes as photosensitizers for DSSCs, an in-depth analysis of the excited state properties of D1, D3 and D4 was performed through TDDFT calculations and TDAS (nanosecond transient difference absorption spectroscopy). The obtained results highlight a trend that was confirmed once D1, D3 and D4 were tested as photosensitizers for DSSC under different conditions. Along the series of the Ru(ii) complexes, the neutrally charged species D3 and D4 displayed the best photovoltaic performances. This journal is

The first real examples of luminescent solar concentrators (LSCs) based on Ir(III) cyclometalates, are described herein. Two new Ir(III) tetrazole complexes, namely [Ir(ppy)2(iQTZ-PPG)]+ and [Ir(npy)2(iQTZ-PPG)]+, where (C^N) = ppy, 2 phenylpyridine or npy = 2-(naphthalen-2-yl)pyridine and iQTZ-PPG = 1-(2-(prop-2-yn-1-yl)-2H-tetrazol-5-yl)isoquinoline, were synthesized, fully characterized and tested as phosphors for colourless LSCs. Notably, increasing quantities (0.2–1.8 wt %) of the new Ir(III) based phosphors were dispersed in different acrylate polymers like poly(methyl methacrylate), PMMA, poly(benzyl methacrylate), PBzMA and poly(cyclohexyl methacrylate), PCHMA, leading to visible transparent polymeric films exhibiting excellent photostability and bright yellow to orange phosphorescent emissions. The performances as solar collectors of all the Ir(III)-doped polymers were investigated, providing results comparable, or superior, to those obtained from colourless LSC based on organic fluorophores. In fact, the best optical efficiency (ηopt up to 7%, combined to transmittance close to 80% at 390 nm) was displayed by the polymer film obtained from physical dispersion of [Ir(ppy)2(iQTZ-PPG)]+ (1.4 wt %) in PCHMA.

The stereodynamic properties of amino bis-mesityl-boranes bearing carbazole and benzocarbazole as donor heterocycles have been investigated by dynamic NMR analysis and simulated by DFT calculations. The π-contribution to the B–N bond has been estimated to be 24 kcal mol−1 when carbazole is the donor heterocycle, while a value of 21.7 kcal mol−1 has been found for the benzocarbazole series. Two rotational barriers were determined for the B–N bond, the lower one (11.1–16.9 kcal mol−1) leading to conformational enantiomers, and the higher one (21.0–24.0 kcal mol−1) likely being responsible for the E-Z isomerization in compounds bearing different aryl rings bound to the boron atom. It has been shown that both kinds of dynamic rearrangements involve a correlated motion of all the three rings. The difference in the ground state geometries and the different π-contributions led to pronounced variations in the fluorescence spectra, due to different geometric rearrangements in the TICT excited state. Stokes shifts larger than 10 000 cm−1 were observed in the carbazole series, with quantum yields up to 50%. It has been found that the π-contribution to the B–N bond in the excited state is still significant, with B–N isomerism likely not taking place on the ns scale.

In this work, Aquivion PFSA resin was shown to be an interesting alternative as a heterogenous catalyst for the continuous gas phase reaction of ethanol dehydration in mild conditions, thanks to its high thermal stability and superacid character. This material was confirmed to have a high thermal stability up to 300 °C, after which the desulphonation process began. Under optimised reaction conditions, the Aquivion catalyst showed a conversion of over 90 % ethanol as well as a selectivity to ethylene. The only detected by-product was diethyl ether, the formation of which was facilitated by low temperature. The dehydration activity was shown to depend on the number of acid sites and material shaping. Fluorescence microscopy, used to study the penetration of different alcohols into the shaped Aquivion, indicated the high polarity of ethanol, enabling the permeation into the pellet structure, thus facilitating the use of the -SO3H that is available on the resin, despite its very low surface area. The catalyst’s durability was proven by a stable operation for 14 h on-stream at 150 °C, without a significant evidence of coke deposition.

This study was aimed at the production and characterization of coated cotton textiles with luminescent ceramic nanophases doped with cationic Ir(III) tetrazole complexes. We confirmed that SiO2 nanoparticles (NPs) do not affect the phosphorescent properties of the complexes that maintain their emission (610 and 490 nm). For the first time we transferred the luminescence feature from nanosol to textile surface, highlighting the advantages of using nanosilica as an encapsulating and stabilizing matrix. The optimized Ir@SiO2 suspensions were homogenously applied onto the cotton surface by dip-pad-dry-cure technique, as proved by the 2p-fluorescence microscope analysis. Once we verified the self-marker properties of the Ir(III) complex, we observed an excellent washing fastness of the coating with a very limited release. SiO2 in the washing water was quantified at maximum around 1.5 wt% and Ir below the inductively coupled plasma optical emission spectrometry (ICP-OES) detection limit of 1 ppm. A Franz cell test was used to evaluate any possible ex-vivo uptake of Ir@SiO2 nanoparticles across human skin tissues, showing that epidermis and dermis stop over 99% of Ir, implying a reduced impact on human health. The light-induced antimicrobial potential of the Ir@SiO2 were assessed toward both Gram(&minus, ) and Gram(+) bacteria. The results encouraged further developments of such functional textiles coated by self-markers and antibacterial active nanophases.

Herein, we describe a new family of tris chelate homoleptic Ru (II) complexes, [Ru(N^N)3]2+, where the role of the diimine-type ligands (N^N) was fulfilled by 2-pyridyl (PTZ) or 2-quinolyl tetrazole (QTZ) derivatives decorated with various alkyl substituents at the N-2 position of the tetrazole ring. The new Ru (II) complexes with general formula [Ru (PTZ-R)3]2+ and [Ru (QTZ-R)3]2+, were obtained as mixtures of facial (fac) and meridional (mer) isomers, as suggested by NMR (1H, 13C) experiments, and confirmed in the case of mer-[Ru (QTZ-Me)3]2+, by X-ray crystallography. The photophysical behavior of the tetrazole-based [Ru(N^N)3]2+ type species was investigated by UV–vis absorption spectroscopy, providing trends typical of polypyridyl Ru (II) complexes. The new homoleptic complexes fac/mer-[Ru (PTZ-R)3]2+ and fac/mer-[Ru (QTZ-R)3]2+ have been assessed for any eventual antimicrobial activity towards two different bacteria such as Gram-negative Escherichia coli and Gram-positive Deinococcus radiodurans. Whereas being inactive toward E. coli, the response of agar disks diffusion tests suggested that some of the new fac/mer Ru (II) complexes could inhibit the growth of D. radiodurans. This effect was further investigated by determining the growth kinetics in liquid medium of D. radiodurans exposed to the fac/mer-[Ru (PTZ-R)3]2+ and fac/mer-[Ru (QTZ-R)3]2+ complexes at different concentrations. The outcome of these experiments highlighted that the turn-on of the growth inhibitory effect took place as the linear hexyl chain was appended to the PTZ or QTZ scaffold, suggesting also how the inhibitory activity appeared more pronouncedly exerted by the facial isomers fac-[Ru (PTZ-Hex)3]2+ and fac-[Ru (QTZ-Hex)3]2+ (MIC = ca. 3.0 μg/ml) with respect to the corresponding meridional isomers (MIC = ca. 6.0 μg/ml).

Platinum(II) olefin compounds [PtMe(N,N′-imino, amide)(η2-olefin)] have been found to dimerize spontaneously in solution, yielding dinuclear complexes through an oxidative coupling. The extended conjugation within the molecules produces an intense blue color, and the properties of the compounds have been investigated through NMR spectroscopy, optical measurements, and theoretical calculations. The solid-state structure of a representative compound has been solved.

The versatile rhenium complex [ReCl(CO)3(bpyC[triple bond, length as m-dash]CH)] (HC[triple bond, length as m-dash]Cbpy = 5-ethynyl-2,2'-bipyridine) is used to generate a series of bimetallic complexes through the hydrometallation of [MHCl(CO)(BTD)(PPh3)2] (M = Ru, Os; BTD = 2,1,3-benzothiadiazole). The ruthenium complex [Ru{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}Cl(BTD)(CO)(PPh3)2] was characterised structurally. Ligand exchange reactions with bifunctional linkers bearing oxygen and sulfur donors provide access to tetra- and pentametallic complexes such as [{M{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}(CO)(PPh3)2}2(S2CNC4H8NCS2)] and Fe[C5H4CO2M{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}(CO)(PPh3)2]2. The effect of the group 8 metal on the photophysical properties of the rhenium centre was investigated using the complexes [Ru{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}Cl(BTD)(CO)(PPh3)2] and [M{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}{S2P(OEt)2}(CO)(PPh3)2] (M = Ru, Os). This revealed the quenching of the rhenium-based emission in favour of weak radiative processes based on the Ru and Os centres. The potential for exploiting this effect is illustrated by the reaction of [Ru{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}Cl(CO)(BTD)(PPh3)2] with carbon monoxide, which results in a 5-fold fluorescence enhancement in the dicarbonyl product, [Ru{CH[double bond, length as m-dash]CH-bpyReCl(CO)3}Cl(CO)2(PPh3)2], as the quenching effect is disrupted.

A family of three neutral iridium(III) tetrazolato complexes are investigated as bacterial imaging agents. The complexes offer a facile tuning of the emission colour from green (520 nm) to red (600 nm) in aqueous media, while keeping the excitation wavelength unchanged. The three complexes do not inhibit the bacterial growth of Bacillus Cereus, used as a model in this study, and exhibit extremely fast cellular uptake. After a minute incubation time, the nontoxic complexes show subcellular localisation in spherical structures identified as lipid vacuoles. Confocal Raman imaging has been exploited for the first time on live bacteria, to provide direct and label-free mapping of the lipid-enriched organelles within B. cereus, complementing the use of luminescent probes. Examination of the Raman spectra not only confirmed the presence of lipophilic inclusions in B. cereus but offered additional information about their chemical composition, suggesting that the lipid vacuoles may contain polyhydroxybutyrate (PHB).

The bis-tetrazolate dianion [1,2 BTB](2-), which is the deprotonated form of 1,2 bis-(1H-tetrazol-5-yl)benzene [1,2-H2BTB], is for the first time exploited as an ancillary N^N ligand for negatively charged [Ir(C^N)2(N^N)](-)-type complexes, where C^N is represented by cyclometalated 2-phenylpyridine (ppy) or 2-(2,4-difluorophenyl)pyridine (F2ppy). The new Ir(iii) complexes [Ir(ppy)2(1,2 BTB)]- and [Ir(F2ppy)2(1,2 BTB)]- have been fully characterised and the analysis of the X-ray structure of [Ir(ppy)2(1,2 BTB)]- confirmed the coordination of the [1,2 BTB](2-) dianion in a bis chelated fashion through the N-atoms adjacent to each of the tetrazolic carbons. Both of the new anionic Ir(iii) complexes displayed phosphorescence in the visible region, with intense sky-blue (λmax = 460-490 nm) or aqua (λmax = 490-520 nm) emissions originating from [Ir(F2ppy)2(1,2 BTB)]- and [Ir(ppy)2(1,2 BTB)]-, respectively. In comparison with our very recent examples of anionic Ir(iii)tetrazolate cyclometalates, the new Ir(iii) tris chelate complexes [Ir(F2ppy)2(1,2 BTB)]- and [Ir(ppy)2(1,2 BTB)]-, display an improved robustness, allowing the study of their reactivity toward the addition of electrophiles such as H(+) and CH3(+). In all cases, the electrophilic attacks occurred at the coordinated tetrazolate rings, involving the reversible - by a protonation deprotonation mechanism - or permanent - upon addition of a methyl moiety - switching of their global net charge from negative to positive and, in particular, the concomitant variation of their photoluminescence output. The combination of the anionic complexes [Ir(F2ppy)2(1,2 BTB)]- or [Ir(ppy)2(1,2 BTB)]- with a deep red emitting (λmax = 686 nm) cationic Ir(iii) tetrazole complex such as [IrTPYZ-Me]+, where TPYZ-Me is 2-(2-methyl-2H-tetrazol-5-yl)pyrazine, gave rise to two fully Ir(iii)-based soft salts capable of displaying additive and O2-sensitive emission colours, with an almost pure white light obtained by the appropriate choice of the ionic components.

Within the general framework of our past and current studies dealing with the investigation of the photophysical properties and the biological behavior of the family of tetrazolato and tetrazole Re(i) complexes, we have endeavored to investigate their potential in the luminescent staining of proteins purified by acrylamide gel electrophoresis. With the aim to provide the first examples of luminescent Re(i) complexes to be exploited for this specific purpose, we have designed and prepared four new Re(i)-based species with the general formula fac-[Re(CO)₃(N^N)(Tph)]²⁻/⁰, where Tph is the 5-(phenyl)tetrazolato anion and N^N is in turn represented by bathophenanthroline disulfonate (BPS), bathocuproine disulfonate (BCS) or by the SO₃-free bathocuproine (BC). In this latter case, the neutral complex fac-[Re(CO)₃(BC)(Tph)] served as a model species for the characterization of the former disulfonate complexes. Its cationic analogue fac-[Re(CO)₃(BC)(Tph-Me)]+was also prepared by a straightforward methylation reaction. All complexes displayed bright phosphorescence in organic media and, relative to their water solubility, the dianionic species fac-[Re(CO)₃(BPS)(Tph)]²⁻and fac-[Re(CO)₃(BCS)(Tph)]²⁻were also highly emissive in aqueous solution. The sulfonate groups played a key role in promoting and significantly enhancing the luminescent staining performances of both the Re(i) complexes fac-[Re(CO)₃(BPS)(Tph)]²⁻and fac-[Re(CO)₃(BCS)(Tph)]²⁻for proteins. Highlighting a response superior to that of Coomassie Blue and comparable to the one obtained by the well-known silver staining method, these dianionic Re(i)-complexes could efficiently detect up to 50 ng of pure Bovine Serum Albumin (BSA), as well as all proteins found in a Standard Protein Marker mix and from a total protein extract. A lower but still good response for luminescent protein staining was surprisingly obtained by employing the-SO₃-free neutral and cationic complexes fac-[Re(CO)₃(BC)(Tph)] and fac-[Re(CO)₃(BC)(Tph-Me)]+, respectively. These preliminary results open up new possibilities for the further widening of the use of Re(i)-based complexes as luminescent protein staining agents. Refereed/Peer-reviewed

Herein we report the easy incorporation of brightly phosphorescent cationic iridium(III) tetrazole complexes into a silica based matrix via an easily scalable colloidal process. For this purpose, two cationic Ir(III) emitters bearing 5-aryl tetrazole ligands (R-CN4) were selected: blue [F2IrPTZ-Me]+ (C^N = F2ppy; N^N = PTZ-Me – 2-(2-methyl-2H-tetrazol-5-yl)pyridine) and red [IrQTZ-Me]+ (C^N = ppy; N^N = QTZ-Me – 2-(2-methyl-2H-tetrazol-5-yl)quinoline). The cationic complexes were readily adsorbed to negatively charged silica nanoparticles and trapped in the sol–gel matrix. The sol-to-solid phase transfer was performed by using an innovative spray-freeze-drying technique, leading to the formation of phosphorescent solid micro-granules. The structural and optical characterisation of the Ir(III) complexes together with SiO2 nanoparticles, nanosols (Ir@SiO2) and powders (Ir@SiO2 powders), revealed how the presence of the Ir(III)-based complexes did not alter the morphology of the colloidal silica or granulated phases. Moreover, the silica matrix did not interfere with the optical properties of the embedded complexes. The distribution of [F2IrPTZ-Me]+ and [IrQTZ-Me]+ in the spray-freeze-dried powders was qualitatively evaluated by fluorescence microscopy, revealing how the luminescent particles were homogeneously dispersed all over the silica matrix. Interestingly, in aqueous solution the release of complex [F2IrPTZ-Me]+ from the corresponding Ir@SiO2 powder is almost negligible, therefore suggesting that a strong interaction occurs between the host–silica matrix and the Ir(III) guest complex., This project has benefited from the EU-H2020 research program under grant agreement no. 654360 and has benefited from the access provided by the Fundacio Institut Català de Nanociència y Nanotecnologia – ICN2 – Barcelona (Spain) and the Foundation for Research and Technology Hellas – FORTH – Heraklion (Greece) within the framework of the NFFA-Europe Transnational Access Activity. The ICN2 is funded by the CERCA programme (Generalitat de Catalunya) and is supported by the Severo Ochoa programme of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, grant no. SEV-2013-0295). The authors wish to thank the Italian Ministry of Education, University and Research (MIUR) for their financial support (PRIN project: Towards a Sustainable Chemistry: Design of Innovative Metal–Ligand Systems for Catalysis and Energy Applications).

Six new biotinylated reagents derived from monocationic pyridyl-1,2,3-triazole-based Ir(III) complexes of the general formula [(C∧N)2Ir(N∧N-spacer-X-CO-biotin)]+, where HC∧N is 2-phenylpyridine, N∧N is the neutral chelating (2-pyridyl)-1,2,3-triazole ligand, the term “spacer” refers to alkyl (−C11H22) or aromatic (p-phenyl- or 4,4′-biphenyl-) chains, and X is NH or O, have been prepared and characterized. Upon photoexcitation, all six complexes in fluid CH2Cl2 and aqueous solutions at room temperature displayed intensewith quantum yields as high as 0.60 (complex 4b)and quite long-lived blue-green luminescence, corresponding in each case to a vibronically structured emission profile peaking at ca. 480 and ca. 508 nm. These features, in combination with the reduced rigidochromic shift that was observed from the same samples frozen at 77 K, suggested the 3LC-type excited states as the prevalent contributors to the emission. The interactions of these new biotinylated complexes with avidin have been studied by 4′-hydroxyazobenzene-2-carboxylic acid (HABA) assays and emission titrations. In general, the amplification of the emission intensity of the Ir(III) complexes occurring upon their interaction with avidin was observed. It is also worth mentioning how a similar or better response was displayed by [(C∧N)2Ir(N∧N-spacer-O-CO-biotin)]+-type complexes, in which biotin is appended to the Ir(III) lumophore through an ester moiety.

Two neutral cyclometalated Ir(III)-tetrazolato complexes that differ by variations of the substituents on either the phenylpyridine or the tetrazolate ligand have been converted into the corresponding methylated and cationic analogues. NMR (1H and 13C) characterization of the Ir(III) complexes provided the results in agreement with the chemo- and regioselective character of methylation at the N-3 position of the Ir(III)-coordinated tetrazolato ring. This evidence was further corroborated by the analysis of the molecular structures of the cationic complexes obtained by X-ray diffraction. In view of the photophysical properties, the addition of a methyl moiety to neutral Ir(III) tetrazolates, which behave as sky-blue or orange phosphors, caused a systematic red shift of their phosphorescence output. The transformation of neutral Ir(III) tetrazolates into cationic Ir(III)-tetrazole complexes was screened for any eventual antimicrobial activity in vitro against Gram negative (E. coli) and Gram positive (D. radiodurans) microorganisms. While both kinds of complexes were not active against E. coli, the conversion of the neutral Ir(III) tetrazolates into the corresponding methylated and cationic Ir(III)tetrazole derivatives determined the turn-on of a good to excellent antimicrobial activity toward Gram positive Deinococcus radiodurans, a non-pathogenic bacterium that is listed as one of the toughest microorganisms in light of its outstanding resistance to radiation and oxidative stress.

The irreversible reaction of methyl triflate with neutral Re(I) tetrazolato complexes of the type fac-[Re(diim)(CO)3(L)], where diim is either 1,10-phenanthroline or 2,2'-bipyridine and L is a para substituted 5-aryltetrazolate, yielded the corresponding cationic methylated complexes. While methylation occurred regioselectively at the N4 position of the tetrazole ring, the cationic complexes were found to exist in solution as equilibrating mixtures of linkage isomers, where the Re(i) centre was bound to either the N1 or N2 atom of the tetrazole ring. The existence of these isomers was highlighted both by NMR and X-ray crystallography studies. On the other hand, the two isomers appeared indistinguishable by IR, UV-Vis and luminescence spectroscopy. The prepared cationic complexes are all brightly phosphorescent in fluid and rigid solutions, with emission originating from triplet metal-to-ligand charge transfer excited states. Compared to their neutral precursors, which emit from admixtures of triplet metal-to-ligand and ligand-to-ligand charge transfer states, the methylated complexes exhibit blue-shifted emission characterised by elongated excited state lifetimes and increased quantum yields. The nature of the excited states for both the neutral and the methylated complexes was probed by resonance Raman spectroscopy and with the aid of time-dependent density functional theory calculations. Lastly, both the neutral and the methylated species were used as emitting phosphors in the fabrication of Organic Light Emitting Diodes and Light Emitting Electrochemical Cells.

INTRODUCTION: The prevalence of maternal group-B-streptococcus (GBS) colonization and risk factors (RFs) for neonatal early-onset disease (EOD) in Europe are poorly defined. Large-scale information concerning adherence to recommendations for preventing GBS-EOD are lacking. MATERIALS AND METHODS: This was a 3-month retrospective area-based study including all regional deliveries ≥35 weeks' gestation (in 2012). The sensitivity, specificity, positive and negative predictive values, odds ratio and receiver operating characteristic (ROC) curve for intrapartum antibiotic prophylaxis (IAP) among full-term and preterm deliveries and prolonged membrane rupture (PROM) were calculated. RESULTS: Among 7133 women, 259 (3.6%) were preterm (35-36 weeks' gestation). Full-term women were 6874, and 876 (12.7%) had at least 1 RF. Most women (6495) had prenatal screening and 21.4% (1390) were GBS positive. IAP was given to 2369 (33.2%) women (preterm, n = 166; full term, n = 2203). Compared to full-term, preterm women were less likely to receive IAP when indicated (73.2% versus 90.3%, p

The first examples of anionic Ir(iii) bis-tetrazolate complexes and their combination with a cationic Ir(iii)tetrazole derivative forming “fully tetrazolate” Ir(iii) based soft salts as O2-sensitive white emitters are described herein.

Background Cases of cytomegalovirus colitis are exceptionally reported in immuno-competent infant. The pathogenesis is uncertain but breast-feeding is considered as a main source of postnatal infection. Case Presentation Here we report a full-term, formula-fed infant who developed a severe cytomegalovirus anaemia and colitis when aged 2 months. Conclusion Even if the molecular identity between the cytomegalovirus-isolate of the infant and the maternal virus could not be demonstrated, we confirmed through laboratory investigation that cytomegalovirus infection was acquired postnatally. However, the source of cytomegalovirus infection remained unclear. Alternative modes of cytomegalovirus transmission are discussed.