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A synthetic approach based on microwave-assisted Pd cross-coupling reactions is developed to obtain two series of push-pull donor-π-conjugated nonadentate coordinating ligands constructed on bispyrazolylpyridine and bisindazolylpyridine units. Both families of ligands formed stable complexes with Europium and Terbium in H2O. To provide a basis to synthesize the best and most effective markers for bioassays, a study of the effect of different substituents on their photophysical behavior is presented in an effort to shed light on the nature of the structure-property relationships. Both families showed better emission properties for Tb(III) than for Eu(III). Bispyrazolylpyridine derivatives were revealed as better sensitizing ligands despite the promising higher absorptivity and red-shifted excitation wavelengths of their counterpart, bisindazolilpyridine. This straightforward synthetic access to 4-substituted pyridines allows easy optimization of the emission properties of lanthanides. In the case of 4-phenylethynyl substituted bispyrazolylpyridine, the emission properties of Eu(III) and Tb(III) complexes were similar, indicating that they can act as a promising long-lived luminescent dual probe in multiplex analysis.

Switchable lanthanide luminescence is a novel proximity-based binary probe technology wherein two oligonucleotide probes are labelled either with lanthanide ion carrier chelate or light-absorbing antenna ligand. A highly luminescent complex is formed when the two label moieties are brought in close contact by adjacent hybridization of the labelled probes to a target sequence. Herein we report how hybridization distance between the labelled probes and single nucleotide mismatches in the target sequence affect to the luminescence intensity of the complex formed from the label moieties. The highest luminescence intensity was observed when the probes were hybridized to full matched target at a distance of 4–10 nucleotides, a fact that indicates the lanthanide complex requires a certain space to be formed. At optimal hybridization distance between the labelled probes the maximal discrimination efficiency between a full matched and a single mismatched target was 1400-fold. Furthermore, computer-based modelling of the luminescent complex formation was in good agreement with the experimental results.

Solid-state CPL measurements were performed for the first time on hybrid, laminar materials based on γ-ZrP pillared with organic diphosphonates. Ad hoc optically pure diphosphonates were synthesized and the luminescence properties of their complexation with Tb(III) were verified in solution. CD and CPL measurements showed that the bistriazolylpyridine chromophores bonded to the metal provided an effective chiral environment that produced significant signals. In the case of the γ-ZrP-derived materials, experimental evidence and simple molecular modeling hinted to the occurrence of supramolecular chirality in the particles, induced by the intrinsic dissymmetry of the organic diphosphonates or by the intercalation of chiral species such as 1-phenethylamine. Chirality at the supramolecular level was revealed in the solid state by the CPL signals measured from reporter Tb(III) ions intercalated in the hybrid matrix.

Batch intercalation experiments have carried out using γ-zirconium phosphate (γ-ZrP) and one of its cationic surfactant forms (γ-ZrP/SUR+) for removing crystal violet from aqueous solutions. The intercalation reactions have conducted along two different intervals of time (24 and 48 h). The intercalation process has followed up by X-ray diffractometry (XRD), UV–Visible and FT-IR spectrophotometries. Regarding γ-ZrP, XRD patterns show that obtained phases are impure, even after 48 h of the reaction time at a maximum dye loading of 18%. On the other side, γ-ZrP/SUR+ gives an impure phase after 24 h while a pure one (2.47 nm) is obtained after 48 h at a maximum dye loading of 19%. In both cases, the observed dye loading values are approximately equal to the one calculated by molecular modeling (ca. 20%). The used analysis approaches prove that dye uptake capacity is a function of the reaction time and inclination angle of the dye molecules inside the solid matrices, where the highest dye uptakes are observed with γ-ZrP and γ-ZrP/SUR+ after 48 h of the reaction time. This time (48 h) is long enough for the dye molecules to be sufficiently accumulated inside the interlayer regions, in such situation dye molecules are forced to stand up perpendicular to the inorganic layers. With respect to intercalation properties, the difference between γ-ZrP and γ-ZrP/SUR+ could be referred to the difference between their gallery heights (1.22 and 3.00 nm, respectively). The pre-intercalation of γ-ZrP with the surfactant molecules assists the inclusion and intercalation of the huge dye molecules into the interlayer region.

The synthesis of polyphenylethynyl diphosphonic acids was accomplished as well as their incorporation to γ-ZrP by topotactic phosphate/phosphonate partial exchange. The materials, characterized by solid-state NMR, XRD, elemental analysis and molecular modelling, bore truly pillared structures with a high degree of ultramicroporosity. The remaining surface phosphates from the partial phosphate/phosphonate replacement were further exchanged with methylphosphonate, phosphite or hypophosphate leading to a library of new materials that retained the pillared ultramicroporous structure. The porous solids displayed reasonable capacities to store hydrogen by physisorption.

The preparation of organic–inorganic materials based on the topotactic exchange reactions of the γ phase of zirconium phosphate and polyphenyl bisphosphonates is reported. The treatment of these materials with hypophosphoric, phosphorous and methylphosphonic acids easily led to an isomerization of the γ phases to their α allotropes. These reactions rendered finely engineered supramolecular structures by means of mild, simple processes performed in the solid–liquid interface. This kind of clean γ-to-α transformations described in our work has few precedents in the literature and allows for the effortless preparation of libraries of similar materials in which the testing of a given set of properties versus subtle structural changes may be easily performed. Using this rationale we have produced materials able to store up to 1.7% (w/w) of H 2 at 77 K and 1 atm with such high ultramicroporosity that the DOE-goal H 2 densities established for 2010 could be complied at pressures well below 5 atm.

The straightforward synthesis of the novel 9-tritylhydrazone erythromycin A and its highly regioselective O-methylation at C(6)–OH are described. Preliminary conformational data based on X-ray diffraction, 1H NMR and molecular mechanics is also presented with the aim of understanding the observed high regioselectivity. The facile synthesis of 6,12-O-dimethylerythromycin A, a standard to assess clarithromycin purity in quality control processes, is reported as well.

The structure of Tb 3+ complexes derived from pyrazole-pyridine tripod was investigated using the semiempirical Sparkle model. Four most probable structures were predicted and their excited electronic states were calculated using the intermediate neglect of the differential overlap/spectroscopic (INDO/S) method. The singlet-excited state frequencies and oscillator strengths were used to predict the absorption spectra which were compared to the experimental one. The results suggest that the terbium tripod complex presents the Tb[podand] · 4H 2 O structure where the podand ligand was coordinated to Tb 3+ ion by six oxygen atoms from the carboxylate groups. This finding agrees with the feeble luminescence experimentally measured for this chelate.

Electron donors based on Ru(bpy) 3 (bpy= 2,2'-bipyridine) are covalently attached to the walls of γ-ZrP and acceptor species based on viologen are arranged side by side following quite simple experimental protocols. The resulting materials are characterized by using the usual techniques and their luminescence and electrochemical properties are assessed. Strong evidence is presented of the efficient occurrence of photoinduced electron transfer in the solid state among the active species attached to the transparent inorganic matrix. The prepared materials may find applications in the clean conversion of light into useful energy.

Fullerene reacted with mono- and diphosphonate-bearing bipyridines by way of Bingel-type reactions to give adducts which were easily transformed in the corresponding dyads by forming Ru(bpy)3 complexes. Electrochemical measurements and the observation of heavy quenching of the Ru(bpy)3 luminescence manifested strong interactions between the active moieties. Attempts to include the dyads into inorganic matrices derived from zirconium phosphate are reported.

A new method for the preparation of clarithromycin is described through the highly regioselective O-methylation at C(6)–OH of the novel derivative 9-pyrimidyloxime erythromycin A. The facile synthesis of 6,11-O-dimethyl- and 6,11,12-O-trimethyl erythromycin A is also reported. These compounds are useful as standards to assess clarithromycin purity in quality control processes.

Using molecular shape for the functional control of multicomponent systems is one of the challenges in the field of supramolecular chemistry. The well-known emission in the visible region of certain lanthanide (III) salts has found a new dimension by the controlled assembly of supramolecular architectures to enshroud and excite the metal. The emission properties of these systems find applications as luminescent probes in sensing schemes, interaction with bio- molecules, or light conversion systems. Complexes of Tb(III) and Eu(III) can in some cases be highly luminescent and typically exhibit emission lifetimes in the millisecond range. These long lifetimes provide a facile means to detect biomolecules labeled with lanthanide from the short-lived background emission of biosystems. The strongly ionic nature of the bonding in solid lanthanide complexes results in coordination geometries that reveal a balance between electrostatic and steric demands. The inclusion of lanthanide guests into macrocycles, cryptands, cavi- tands and spherands had the purpose of shielding the metals from solvent molecules whose OH, NH or CH groups are able to heavily quench lanthanide luminescence (intensity and lifetime) by deactivation of their emissive levels by vi- bronic coupling. The literature on the various chemical systems, based on nitrogen heteroaromatic rings, used to sensitize lanthanides will be thoroughly reviewed including those molecules synthesized by the authors which displayed high quantum yield of lan- thanide emission.

The pillaring of γ-zirconium phosphate with either dissymmetric or non-dissymmetric polyethylenoxa diphosphonates leads to organic–inorganic nanostructures, in which the coiling of organic columns is the source of supramolecular chirality and chiral memory.

An expeditious synthesis of new cryptands derived from N,C-pyrazolylpyridine and their full characterization is reported. Emission lifetimes of the europium and terbium cryptates were in the range of milliseconds and terbium quantum yield was high.

The construction of organic−inorganic scaffolds based on γ-zirconium phosphate and polyethylenoxa diphosphonates is described. Microcrystalline materials with a controlled, low degree of pillaring are synthesized and characterized by elemental analysis, X-ray powder diffraction, solid-state NMR, and thermogravimetric analysis. The mechanism for the topotactic polyethylenoxa-pillaring reaction is proposed and confronted with previous ones suggested for the reaction of nonpolar organic diphosphonates. The affinity among the polyethylenoxa chains and the superficial acidic phosphates of the layered salt is thus clearly evidenced. The work shows how the inner structure of the pillared microcrystals may be easily modified by a second exchange of the remaining superficial phosphates by other phosphorus species as the low-polar hypophosphite. The rigidity of the layers and the wedge-like effect of intercalated amines at the edges of the microcrystals cause them to increase the interlayer distance, and hence poro...

Pillared γ-zirconim phosphate at low level with a diphosphonic acid resulting from the addition of pentaethyleneglycol to diethyl vinyl phosphonate was prepared and used as a porous matrix to inter...

Two macrobicyclic ligands derived from an 18-membered tetralactam ring and 2,2′-bipyridine or 2,6-bis(pyrazol-1-yl)pyridine moieties, 1 and 2, respectively, form stable complexes with GdIII, EuIII, and TbIII ions in aqueous solution. The ligand-based luminescence is retained in the GdIII cryptates, whereas this radiative deactivation is quenched in the EuIII and TbIII cryptates by ligand-to-metal energy transfer, resulting in the usual metal-centered emission spectra. Singlet- and triplet-state energies, emission-decay lifetimes, and luminescence yields were measured. [Tb⊂1]3+ cryptate shows a long luminescence lifetime (τ=1.12 ms) and a very high metal luminescence quantum yield (Φ=0.25) in comparison with those reported in the literature for Tb3+ complexes sensitized by a bipyridine chromophore. By comparison to [Ln⊂1]3+, [Ln⊂2]3+ presents markedly lower luminescence properties, due to worse interaction between the 2,6-bis(pyrazol-1-yl)pyridine unit and the metal ion. Moreover, the luminescent metal and the triplet ligand energy levels of [Eu⊂2]3+ do not match. The effects of H2O molecules coordinated to the metal centre and of thermally activated decay processes on nonradiative deactivation to the ground-state are also reported.

Pentachlorophenol (PCP) is a hazardous pollutant with toxicity and potential carcinogenic properties being a serious threat to the environment. In this work, the development of an immunoassay for PCP is presented. A hapten was synthesised and conjugated to protein for rabbit immunisation. Three polyclonal antibodies were obtained and the best results were achieved in the antibody-coated format using antiserum R3. Calibration range was 0.3–30.5 ng ml −1 , with an average I50 value of 2.9 ng ml −1 and a detection limit of 0.1 ng ml −1 . The specificity of the assay was tested against PCP structurally related compounds. The method is highly specific for PCP and shows low cross-reactivity (CR) for chlorine-containing phenols, nitrophenols, benzenic and piridinic compounds. The good recoveries achieved with different water samples indicate that this assay can be a good alternative method for the determination of PCP in this kind of samples. © 2002 Elsevier Science B.V. All rights reserved.

Several new ionophores derived from crown ethers and iminodiacetic subunits attached to 3-aroylcoumarins have been synthesized and fully characterized. The alkaline-earth complexes of these new ligands were studied from their UV–visible and fluorescence data. Some systems displayed strong bathochromic shifts upon complexation with Mg 2+ that may make them useful signaling devices of this cation. The corresponding Eu 3+ and Tb 3+ chelates were easily formed and their photophysical properties were measured. In all the cases, lanthanide emission lifetimes were in the range of milliseconds albeit quantum yields were low. Possible energy-transfer mechanisms are discussed. © 2002 Elsevier Science B.V. All rights reserved.

New ionophores derived from azacrown ethers attached to coumarins have been synthesized and characterized. The alkaline-earth complexes of these new ligands were studied from their UV–vis, NMR, and fluorescence data. Some systems displayed bathochromic shifts and fluorescence decreases upon complexation with Ca2+ that may make them useful signaling devices of this metal.Key words: alkaline earth, emission, molecular modeling.

The intercalation materials prepared from the laminar salt gamma-zirconium phosphate and various dyads formed from Ru(bpy)(3) and viologens were tested as photoactive components in dye-sensitised solar cells. The efficiencies significantly increased, up to 0.2 %, when the materials were treated with the panchromatic N535 dye. A mechanism for this double sensitisation process is proposed, which should enable further improvement of these gamma-ZrP-based materials as a reasonable alternative to the usual Ti-based dye-sensitised solar cells., The group from Universidad Autonoma de Madrid (UAM) is grateful to ERCROS-Farmacia SA (Aranjuez, Spain) for sponsoring the UAM-ERCROS Chair in Chemistry that generously funded this work, in part. The group from Universidad del Pais Valenciano-Consejo Superior de Investigaciones Cientificas (UPV-CSIC) group is grateful to the Spanish former Ministerio de Ciencia e Innovacion de Espana (MICINN) for grant CTQ2012-32315. P.A. thanks the MICINN for a Juan de la Cierva research contract.

[structure: see text] New macrocyclic chelates based on bis-pyrazolylpyridine and diethylenetriaminepentaacetic acid are synthesized, and the remarkable luminescence properties of their lanthanide chelates are reported.

We have devised efficient reaction pathways to attach aminopolycarboxylate subunits to the 3-aroylcoumarin chromophore. Two series of compounds were thus prepared in which the chelating arms were directly bonded to the coumarin ring (series A) or to the 3-aroyl moiety (series B). The corresponding Eu(III) and Tb(III) chelates were easily formed and their photophysical properties measured. In all the cases, lanthanide emission lifetimes were in the range of ms. Unfortunately, quantum yields were relatively low. Measurement of T1 states gave too low range of values to sensitize Tb(III). In fact, the metal emission of Tb(III) chelates of series A was not observed. However, series B was able to sensitize both metals. The absorption/energy-transfer/emission mechanisms are discussed.

The synthesis of macrobicyclic cryptands 1 , 2 from an 18-membered diazatetralactam and 6,6′-bis(bromomethyl)-2,2′-bipyridine or 2,6-bis(3-bromomethyl-1-pyrazolyl)pyridine has been investigated using various metal carbonates. The analysis of the distribution products by gel permeation chromatography showed that macrocyclization process was markedly conditioned by cation template effects. Optimum yields were obtained for Li + and Na + in the preparation of 1 and 2 , respectively. The cryptate structure of the corresponding complexes of Ln(III) (Ln=Eu, Tb, Gd) is discussed on the basis of spectroscopic and photophysical data.

Substituted 3-aroylcoumarins incorporated in a polyethylenoxy cryptand (2.2.2) by the 3-aroyl group were synthesized with the purpose of developing new markers to be used in time-resolved fluorimetric bioaffinity assays based on the unique luminescence properties of Eu(III) and Tb(III) ions. Some spectral properties and luminescence intensities of the complexes were measured in acetonitrile and MeOH. The mechanism of metal sensitization depended on lanthanide and will be discussed in detail. Copyright © 2000 John Wiley & Sons, Ltd.

The synthesis by means of ‘click’ chemistry of a new ligand bearing the bis-triazolylpyridine motif and pendant phosphonate groups is described. The topotactic phosphate/phosphonate exchange of the ligand into gamma-zirconium phosphate led to an organic–inorganic-layered material which revealed an excellent matrix to achieve the efficient sensitization of emitting lanthanides.

The enantioselectivity exerted by a new series of chiral catalysts containing N,O-heterocycles of different sizes has been checked in the addition of diethylzinc to benzaldehyde, which was used as a model reaction. The catalysts were derived from natural amino acids, following a relatively simple procedure, and in several cases excellent ee values were obtained. The results were complementary since ee's ranged from 98% (R) to 94% (S) excesses of the final 1-phenylpropan-1-ol. Molecular mechanics calculations suggested that the production of the R alcohol may be explained by a mechanism similar to that described by Noyori, in which ZnEt2 interacts solely with the N–C–C–OH fragment, whereas the formation of the S enantiomer needed the direct participation of the lateral chain of the parent amino acid and the N,O-heterocycle.

The synthesis of four new podands with three arms containing the N,C-pyrazolyl-pyridine chromophore is described with the aim of using the resulting tripods as ligands to sensitize lanthanide luminescence.

A new, relatively simple tetra-acid ligand derived from acetophenone was synthesized and its luminescence properties when forming Eu(III) and Tb(III) chelates were evaluated in aqueous and methanol solutions. The titled compound displayed excellent quantum yields of triplet sensitization of lanthanide luminescence (0.20–0.25 for Eu 3+ and 0.95–1.00 for Tb 3+ ). Results suggested that the metal and the cromophore should be in close contact and that the iminodiacetic arms isolate very well the metal from the surrounding OH oscillators which normally quench lanthanide luminescence.

The luminescence properties of 41 different Eu(III) and Tb(III) chelates that were synthesized with the purpose of developing new markers for chemical and biochemical applications were measured in aqueous solution and their suitability for labels in time-resolved immunoassays were evaluated. In spite of the influence of numerous factors on the luminescence quantum yields, a clear correlation was obtained between the energies of the lowest triplet state levels of the ligands and lanthanide (III) luminescence quantum yields of the respective chelates. Simultaneously Eu(III) and Tb(III) ions were observed to accept energy by their several different 5Dj, resonance levels depending on the energy of the lowest triplet state level of the ligand, and the Tb(III) luminescence quantum yields were observed to decrease due to the energy back transfer from excited Tb(III)∗ to the ligand when the energy difference between the 5D4 level of Tb(III) and the lowest triplet state energy level of the ligand is less than 1850 cm−1.

The synthesis of novel TbIII labels suitable for protein labelling are reported. Their luminescence properties as antibody conjugates were measured and compared to the results of corresponding TbIII chelates of the parent ligand structures. When the lowest triplet-state energy level of the parent donor ligand was over 23000 cm−1, i.e., the energy gap between the 5D4 level of TbIII and the lowest triplet-state energy level of the ligand exceeded 2600 cm−1, the label derivative with a long decay time (τ = 1.35–2.93 ms) and a high luminescence yield (ϵ. Φ = 3770–4560) was found to be suitable for bioaffinity assays.

The synthesis of three novel pyrazole-containing complexing acids, N,N,N′,N′-{2, 6-bis[3-(aminomethyl)pyrazol-1-yl]-4-methoxypyridine}tetrakis(acetic acid)(1), N,N,N′,N′-{2, 6-bis[3-(aminomethyl)pyrazol-1-yl]pyrazine}-tetrakis(acetic acid) (2), and N,N,N′,N′-{6, 6′-bis[3-(aminomethyl)pyrazol-1-yl]-2, 2′-bipyridine}tetrakis(acetic acid) (3) is described. Ligands 1–3 formed stable complexes with EuIII, TbIII, SmIII, and DyIII in H2O whose relative luminescence yields, triplet-state energies, and emission decay lifetimes were measured. The number of H2O molecules in the first coordination sphere of the lanthanide ion were also determined. Comparison of data from the EuIII and TbIII complexes of 1–3 and those of the parent trisheterocycle N,N,N′,N′-{2, 6-bis[3-(aminomethyl)pyrazol-l-yl]pyridine}tetrakis(acetic acid) showed that the modification of the pyridine ring for pyrazine or 2, 2′-bipyridine strongly modify the luminescence properties of the complexes. MeO Substitution at C(4) of 1 maintain the excellent properties described for the parent compound and give an additional functional group that will serve for attaching the label to biomolecules in bioaffinity applications.

The topotactic exchange reactions of γ-zirconium phosphate and γ-zirconium phosphate/methylphosphonate with phosphonic acids derived from azacrown ethers of different sizes was examined. Prior intercalation of hexylamine was necessary in most cases to attain the maximum exchange level predicted by molecular modeling. Materials with imbricated or nonimbricated layers were obtained depending on crown size and exchange level. Exchange of methylphosphonates in γ-zirconium phosphate/methylphosphonate was only observed when hexylamine had previously been intercalated. The exchange with the bisphosphonic acid derived from 1,10-diaza[18]-crown-6 gave a material with an interlayer distance compatible with pillaring of the γ-phase. The materials obtained from the exchange reactions of γ-zirconium phosphate with phosphonic acids derived from [12]crown-4 and [18]crown-6 showed thermodynamic selectivities towards Na+ and K+, respectively, that were much higher than those observed for the simple crowns in solution. This observation suggests that the inorganic molecular framework enhances molecular recognition by minimization of solvation effects.

Phosphonates of RuII(bpy)3 complexes and C60 were covalently grafted within the layers of γ-zirconium phosphate. The synthesis of some phosponate derivatives of C60 is thus described. Confined electron transfer was effected as demonstrated by Ru luminescence-quenching experiments. The solid composite materials were characterized by solid-state NMR, powder x-ray diffraction, thermogravimetry, elemental analysis and ICP-MS.

Reaction between palladium(II) acetate and bis(arylpyrazolyl)methanes with two aryl groups 3-RC 6 H 4 , 2a–c or the 3-RC 6 H 4 and one 5-RC 6 H 4 , 3a–c (R = H, 3′-OCH 3 , or 2′-Br) 3a–c in refluxing acetic acid, affords metallacycles of stoichiometry LPd 2 , with two different five- and six-membered palladacycles, one containing an aromatic carbon-metal bond and the other a pyrazole carbon-metal bond, repectively. Treatment of acetate-bridged palladacycles 5a–c and 6–c with Tl(acac) yields monomeric products 7a–c and 8a–c of formula [LPd 2 (acac) 2 ]. The products have been characterized by elemental analysis (C, H, N) and NMR spectroscopy. The preferential formation of a six-membered metallacycle in the first step of the reaction is discussed.

Three differently substituted 3-aroylcoumarins, L 1–3 , with tetraacid chelating subunits anchored at the 3-benzoyl group were synthesized, and their complexes with Eu 3+ and Tb 3+ formed as new potential bioaffinity-assay markers. Some spectral and luminescence properties of the complexes in water and methanol are reported.

The preparation of γ-zirconium phosphate exchanged with N-(2-ethylphosphonic)-aza-18-crown-6 is reported as well as its 31P NMR data, powder XRD pattern, molecular modeling and preliminary ion-exchange experiments.

The synthesis of novel optically active crown ethers derived from (1 R )-(+)-camphor is described. The mechanism of their catalytic effect upon the Michael addition of phenylacetate to acrylate is discussed in terms of kinetic vs . thermodynamic control in the formation of the catalytic ion-pair complexes. The relative basicity of the complexes formed between the alkaline metals and the unprotonated chiral crown ethers plays an important role in the sterochemical outcome. AMBER and AM1 calculations support that the reaction in which the best e.e. (83%) is obtained proceeds under kinetic control.

The preparation of 1 as a model for negative allostery is described. Transport experiments (bulk liquid membrane) of alkyl di- and monoammonium cations in the presence or absence of ZnI2 in the receiving phase evidenced strong negative allosteric effects of the metal towards ammonium complexation.

[EN] The performance of photovoltaic cells using as semiconductor a film of layered γ-zirconium phosphate (γ-ZrP) containing Ru(bpy) 3 and bipyridinium ions (viologens) as electron relays has been studied. The materials are easily prepared by intercalation of Ru complexes and the bipyridinium ions into preformed γ-ZrP nano sheets as colloidal solutions in the appropriate solvent and concentration. High loading of these two guests has been obtained as determined by elemental analysis. Inclusion of Ru(bpy) 3 complex and bipyridinium in the intergallery spaces of γ-ZrP can be assessed by powder XRD monitoring of the d 100 peak. A dyad was also synthesized where the Ru(bpy) 3 and the 4,4′-bipyridinium were covalently connected by a four-methylene tether. The semiconducting behavior of layered γ-ZrP was supported by cyclic voltammetry (reversible reduction peak at -0.6 V), observation of photocurrent and Mott-Schottky measurements (flat band potential ∼-1.3 V vs. NHE) of thin films of this material supported on FTO electrode. Photovoltaic cells based on γ-ZrP containing Ru(bpy) 3, exhibited similar V OC (∼0.5 V) and fill-factor values (0.3-0.4), differing in the current density and therefore in their efficiency. The maximum efficiency was obtained for the material containing high loading of the dyad (J SC = 0.383 mA/cm 2, efficiency 0.1%). The photo response spectrum shows that the main limitation of these materials is still the inefficient photo sensitization of the semiconductor by the dye, probably due to the high negative flat band potential of γ-ZrP. © 2011 The Royal Society of Chemistry., The UPV-CSIC group is grateful to the Spanish MICINN for grant CTQ2009-11863. The UAM group thanks ERCROS-Farmacia S.A. for indirect funding and regrets that the financial backing from MICINN has been negated after the generous grants received in the near past (MAT2002-03243, MAT2006-00570).

Synthesis of fluoroionophores consisting of 3-benzoylcoumarins fused with crown ethers in two different modes are described. The resulting macrocycles bore emission properties strongly dependent on metal ions and coumarin substitution and may be therefore used as cation dependent fluorescence signaling systems or triplet sensitizers for lanthanide luminescence.

A short and efficient synthesis of N, N, N′, N′-[2,6-bis(3-aminomethyl-1-pyrazolyl)pyridine]-tetrakis(acetic acid)(6), an analogue of terpyridine with additional chelating iminodiacetic groups, is described. Compound 6 forms stable complexes with EuIII and TbIII in water whose relative luminescence yields, excitation maxima and emission decay lifetimes have been measured. The number of water molecules in the first coordination sphere of the europium complex have also been determined. Comparison of data from the EuIII and TbIII complexes of 6 and of the parent trisheterocycle diacid 2,6-bis(3-carboxy-1-pyrazolyl)pyridine shows that the iminodiacetic subunits give extra stabilization to the complexes and are essential to protect the metal from the water environment.