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A multi-analytical approach was used to comprehensively characterize the acid-base, thermal, and surface properties of agri-food processing wastes (i.e., original and pre-treated bergamot, grape and olive pomaces). These biomasses, often underutilised and inadequately studied in terms of their physicochemical properties, were investigated under varying ionic strength conditions at t = 25 °C. This investigation uniquely integrates multiple advanced techniques: Brunauer–Emmett–Teller porosimetry, Scanning Electron Microscopy, Thermogravimetric Analysis coupled with Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, Attenuated Total Reflectance Fourier-Transform Infrared, and potentiometry to provide a holistic understanding of these biomasses potential for environmental remediation. The modelling of ionic strength-dependent acid-base behaviour, established using an extended Debye–Hückel-type equation, revealed the dominant role of carboxylic groups as active sites across all pomace types, although with variations in abundances across the different samples. Additionally, morphological analysis highlighted the presence of irregularly shaped particles, heterogeneous size distributions, and distinct thermal stability trends, with grape pomace exhibiting the highest mass loss. These findings underscore the significant potential of these biomasses for the remediation of cationic pollutants from natural waters. Moreover, this comprehensive characterisation not only advances the understanding of agri-food waste valorisation but also provides a robust framework for designing targeted strategies in environmental applications. [ABSTRACT FROM AUTHOR]

Background: Benzoxazole-containing ligands find many applications both in medicinal chemistry, catalysis and fluorescence chemosensing. Benzoxazole-containing macrocycles could be therefore a good strategy to achieve stable and selective fluorescent complexes with suitable metal ions. In this work, the synthesis, binding, and photochemical properties of a new fluorescent ligand (L) are reported. L is a cyclophane macrocycle containing the 1,3-bis(benzo[d]oxazol-2-yl)phenyl (BBzB) fluorophore and an aliphatic tetra-amine chain to form the macrocyclic skeleton. Methods: Spectrophotometric and spectrofluorimetric measurements, 1H NMR analysis, and DFT calculations were performed. Results: L behaves as a PET-mediated chemosensor, being emissive at 390 nm at acidic pH and non-emissive at basic pH. The chemosensor is able to detect Zn2+ and Cd2+ in an aqueous medium (acetonitrile–water, 4:1 v/v) at neutral pH through a CHEF effect upon metal ion coordination. Paramagnetic metal ions (Cu2+) and heavy atoms (Pb2+, Hg2+) resulted in a quenching of fluorescence or very low emission. Conclusions: The new cyclophane macrocycle L was revealed to be a selective PET-regulated chemosensor for Zn2+ and Cd2+ in an aqueous medium, being able to bind up to two and one metal cations, respectively. The molecule showed a shifted emission towards the visible region compared to similar systems, suggesting a co-planar conformation of the aromatic fragment upon metal coordination. All these data are supported by both experimental measurements and theoretical calculations. [ABSTRACT FROM AUTHOR]

The title compound, [CaCo2(C22H30N4O6)2](ClO4)2·1.36H2O or {Ca[Co(H–2L1)]2}·2ClO4·1.36H2O {where L1 is 4,10-bis­[(3-hy­droxy-4-pyron-2-yl)meth­yl]-1,7-dimethyl-1,4,7,10-tetra­aza­cyclo­dodecane}, is a trinuclear complex whose asymmetric unit comprises a quarter of the {Ca[Co(H–2L1)]2}2+ trinuclear complex, half of a perchlorate ion and 0.34-water mol­ecules. In the neutral [Co(H–2L1)] moiety, the cobalt ion is hexa­coordinated in a trigonal–prismatic fashion by the surrounding N4O2 donor set. A Ca2+ cation holds together two neutral [Co(H–2L1)] moieties and is octa­coordinated in a distorted trigonal–dodeca­hedral fashion by the surrounding O atoms belonging to the deprotonated oxide and carbonyl groups of two [Co(H–2L1)] units. The coordination of the CoII cation preorganizes L1 and an electron-rich area forms, which is able to host hard metal ions. The comparison between the present structure and the previously published ones suggests a high versatility of this ligand; indeed, hard metal ions with different nature and dimensions lead to complexes having different stoichiometry (mono- and dinuclear monomers and trinuclear dimers) or even a polymeric structure. The heterotrinuclear CoII–CaII–CoII complexes are connected in three dimensions via weak C—H...O hydrogen bonds, which are also responsible for the inter­actions with the perchlorate anions and the lattice water mol­ecules. The perchlorate anion is disordered about a twofold rotation axis and was refined giving the two positions a fixed occupancy factor of 0.5. The crystal studied was refined as a two-component inversion twin [BASF parameter = 0.14 (4)]. [ABSTRACT FROM AUTHOR]

The title compound, {[Ba{Co(H-2L1)}(ClO4)(H2O)]ClO4}n, L1 = 4,10-bis­[(3-hy­droxy-4-pyron-2-yl)meth­yl]-1,7-dimethyl-1,4,7,10-tetra­aza­cyclo­dodeca­ne, is a one-dimensional coordination polymer. The asymmetric unit consists of a {Ba[Co(H–2L1)](ClO4)(H2O)}+ cationic fragment and a non-coordinating ClO4− anion. In the neutral [Co(H–2L1)] moiety, the cobalt ion is hexa­coordinated in a trigonal–prismatic fashion by the surrounding N4O2 donor set. The Ba2+ ion is nine-coordinated and exhibits a distorted [BaO9] monocapped square-anti­prismatic geometry, the six oxygen atoms coming from three distinct [Co(H–2L1)] moieties, while the remaining three vertices are occupied by the oxygen atoms of a bidentate perchlorate anion and a water mol­ecule. A barium–μ2-oxygen motif develops along the a axis, connecting symmetry-related dinuclear BaII–CoII cationic fragments in a wave-like chain, forming a one-dimensional metal coordination polymer. Non-coordinating ClO4− anions are located in the space between the chains. Weak C—HO hydrogen bonds involving both coordinating and non-coordinating perchlorate anions build the whole crystal architecture. To our knowledge, this is the first example of a macrocyclic ligand forming a BaII-based one-dimensional coordination polymer, containing CoII ions surrounded by a N4O2 donor set. [ABSTRACT FROM AUTHOR]

The synthesis and the structural characterization of a cyclic hexapeptoid with four methoxyethyl and two propargyl side chains have disclosed the presence of a hydrate crystal form [form (I)] and an anhydrous crystal form [form (II)]. The relative amounts of form (I) and form (II) in the as-purified product were determined by Rietveld refinement and depend on the purification procedures. In crystal form (I), peptoid molecules assemble in a columnar arrangement by means of side-chain-to-backbone C=CH...OC hydrogen bonds. In the anhydrous crystal form (II), cyclopeptoid molecules form ribbons by means of backbone-to-backbone CH 2 ...OC hydrogen bonds, thus mimicking β-sheet secondary structures in proteins. In both crystal forms side chains act as joints among the columns or the ribbons and contribute to the stability of the whole solid-state assembly. Water molecules in the hydrate crystal form (I) bridge columns of cyclic peptoid molecules, providing a more efficient packing.

In the title hydrated salt, C36H66N8O(6+)·6ClO4(-)·1.5H2O, the asymmetric unit consists of a hexa-protonated [H6L](6+) cation, five perchlorate anions in general positions, two on twofold rotation axes (one of which is disordered), and two water mol-ecules of crystallization in general positions, one of them disordered around a twofold crystallographic axis. In the [H6L](6+) cation, two strong intra-molecular N-H⋯N hydrogen bonds occur, involving the N atoms of the oxadiazole ring as acceptors and the closest NH(+) groups of each dipropyl-enetriamine unit. In the crystal, the [H6L](6+) cations form channels along the a-axis direction, in which the perchlorate counter-ions and the water mol-ecules are lodged. The crystal packing features a network of N-H⋯O and O-H⋯O hydrogen bonds involving the NH(+) groups of the [H6L](6+) cation, the perchlorate anions and the water mol-ecules.

The title compound (C(16)H(22)N(2)O(6))[PtCl(4)]·2H(2)O, shows anti-proliferative activity in eight tumor cell lines. The asymmetric unit consists of one solvent water mol-ecule on a general position, and one half of each of the polyammonium cation and the tetrachloridoplatinate(II) anion, both of them located on centers of inversion. In the crystal, the cations are connected via hydrogen bonding between the carbonyl O atoms and the hydroxyl H atoms into zigzag chains that elongate in the c-axis direction. In addition, the carbonyl O atom is hydrogen-bonded to the water mol-ecule which, in turn, inter-acts with the [PtCl(4)](2-) anion. Finally, the chains are linked by N-H(+)⋯Cl inter-actions into a three-dimensional network.