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The interaction of decavanadate with the cationic organic dyes methylene blue (MB), toluidine blue (TB) and rhodamine B (RB) was explored. For that purpose, a novel decavanadate salt (2,3-ampH)6[V10O28]·4H2O (2,3-ampV10), where 2,3-ampH+ = 2-amino-3-methylpyridinium, and two salts with the organic dyes (MB)4[H2V10O28]·10.8H2O (MBV10) and (TB)4(H2V10O28)·10H2O (TBV10) were synthesized. The compounds were characterized by elemental analysis, powder X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy and infrared spectroscopy. The salts 2,3-ampV10 and MBV10 were also characterized by single-crystal X-ray diffraction, while TBV10 was isolated as an amorphous solid. The supramolecular features of MBV10 showed columns of MB cations connected to V10 through H-bond interactions that resulted in channels filled with water molecules. The absorption spectrum of MBV10 was studied by density functional theory (DFT) calculations at the X3LYP/def2-TZVP level using the crystallographic data. The efficacy of 2,3-ampV10 to bleach MB solutions at pH 6.2–6.5 was outstanding, achieving nearly 90% discoloration in only 5 min, presenting moderate efficacy towards TB and quite negligible towards RB. Moreover, a metachromatic effect was observed in the TB solution at pH 3. The IR spectra of the isolated solids and the mass spectra of the supernatants suggest both adsorption and cation exchange as the main responsible processes for the bleaching of MB and TB solutions. The present work has tackled many fronts related to the chemistry of POVs, mainly synthetic, structural, and environmental approaches. [ABSTRACT FROM AUTHOR]

In this work, the study of the new ligand 3,3′-bis[N,N-bis(pyridine-2-ylmethyl)aminomethyl]-2,2′-dihydroxybiphenyl (L) is reported, where a central 2,2′-biphenol (BPH) fluorophore was functionalized at 3,3′-positions with two dipicolylamine (DPA) side arms as receptor units. Following the synthesis and full chemical–physical characterization, the acid–base and Zn2+-coordination abilities of L were investigated through a combination of potentiometric, UV-Vis, fluorescence, NMR, XRD and DFT measurements. The optical properties of the ligand turned out to be strongly dependent on the pH, being straightforwardly associated with the protonation state of the BPH moiety, whereas its peculiar design allowed to form stable mono and dinuclear Zn2+ complexes. In the latter species, the presence of two Zn2+ ions coordinatively unsaturated and placed at close distance to each other, prompted us to test their usefulness as metallo-receptors for two environmental pollutants of great relevance, ibuprofen and ketoprofen. Potentiometric and fluorescence investigations evidenced that these important non-steroidal anti-inflammatory drugs (NSAIDs) are effectively coordinated by the metallo-receptors and, of relevance, both the stability and the fluorescence properties of the resulting ternary adducts are markedly affected by the different chemical architectures of the two substrates. This study aims at highlighting the promising perspectives arising from the use of polyamino phenolic ligands as chemosensors for H+/Zn2+ and other additional anionic targets in their metal-complexed forms. [ABSTRACT FROM AUTHOR]

Triamine receptors containing anthracene units are able to bind and sense ketoprofen via fluorescence enhancement in a H2O/EtOH 50 : 50 (Vol : Vol) mixture exploiting their protonation features, which are tuned by the interaction with the analyte. [ABSTRACT FROM AUTHOR]

Herein we describe the binding abilities of Zn(II) complexes of [12]aneN4- (L1) and [9]aneN3-based receptors (L2, L3) towards the herbicides N-(phosphonomethyl)glycine (glyphosate, H3PMG) and 2-amino-4-[hydroxy(methyl)phosphoryl]butanoic acid (glufosinate, H2GLU), and also aminomethylphosphonic acid (H2AMPA), the main metabolite of H3PMG, and phosphate. All ligands form stable Zn(II) complexes, whose coordination geometries allow a possible interaction of the metal center with exogenous anionic substrates. Potentiometric studies evidenced the marked coordination ability of the L2/Zn(II) system for the analytes considered, with a preferential binding affinity for H3PMG over the other substrates, in a wide range of pH values. 1H and 31P NMR experiments supported the effective coordination of such substrates by the Zn(II) complex of L2, while fluorescence titrations and a test strip experiment were performed to evaluate whether the H3PMG recognition processes could be detected by fluorescence signaling. [ABSTRACT FROM AUTHOR]

The studies of structures of phenanthroline(L) indicate that it is a branched ligand with a central nitrogen atom. The binding properties of L towards copper and zinc are studied by potentiometric and NMR spectroscopy and the different binding areas in L for metals are discovered

The basicity and binding properties of L toward Cu(II), Zn(II), and CI(super -) were determined by means of potentiometric measurements in aqueous solution. Studies revealed that the [Zn(sub 2)H(sub -1)L](super 3+) species is able to bind one phosphate at physiological pH.

Research has been conducted on the dichloro-bridged arylbicycloheptylpalladium complexes. The synthesis and characterization of these complexes have been carried out and the dimers bearing methyl groups at different para, meta and ortho aromatic positions have been investigated and discussed.

Research has been conducted on the coordination properties of the amino-phenolic ligand toward the zinc ion. The investigation of these properties via the potentiometric measurements in the aqueous solution is reported and the results indicate that this ligand forms mono- and dinuclear complexes with zinc.

Research has been conducted on the salts that possess H-bonded supramolecular helical architectures. Results indicate that these salts can bee assembled by the correct partner selection via a dicarboxylic acid that matches the complementarity prerequisites of the building blocks.