Thermodynamic parameters (ΔG°, ΔH°, TΔS°), obtained by means of potentiometric and isothermal titration calorimetry (ITC) methods, for the binding equilibria involving anions high negative charge, like SO42–, SeO42–, S2O32– Co(CN)63–, nitroso-amino-pyrimidine receptors in water suggested that anion−π interactions furnish a stabilization about −10 kJ/mol to free energy association. These are almost athermic favored large entropic contributions which likely due reduced hydrophobic pyrimidine...

Binding of anions great environmental concern such as SO(4)(2-), PO(4)(3-), AsO(4)(3-), HgCl(4)(2-), and CrO(4)(2-) by the protonated forms a tren-like (tren = tris(2-aminoethyl)amine) ligand (HL) functionalized with pyrimidine residue was studied means potentiometric measurements isothermal titration calorimetry (ITC) affording log K, ΔH°, TΔS° values for formation relevant complexes. The complexes show high to very stability due particular topology electronic properties which is able use...

The interaction of SO42− with polyammonium cations derived from fourteen polyamines (5 polyazacycloalkanes, 2 polyazacyclophanes, 3 phenanthrolinacyclophanes, dibenzenacyclophanes and acyclic polyamines) in aqueous solution has been studied by means potentiometric microcalorimetric techniques. Only 1 : receptor–anion complexes have found solution. Complexed species considerable stability are formed, although the two (dimethylpentaethylenehexaamine dimethylhexaethyleneheptaamine) smallest...

The results presented in this work are related to the design of a guideline develop specific properties at surface an activated carbon (AC). For this, two model aromatic compounds have been synthesized and their electrolytic behavior aqueous solutions was studied by potentiometric method. textural characteristics were determined porosimetry methods. nature oxygen-carrying functions acid-base AC characterized TPD titration methods, respectively. adsorption desorption equilibria on measured...

Enhanced anion recovery from water is achieved upon functionalization of activated carbon with polyamine groups.

Controlling graphene conductivity is crucial for its potential applications. With this focus, paper shows the effect of non-covalent bonding a pyrimidine derivative (HIS) on electronic properties (G). Several G-HIS hybrids are prepared through mild treatments keeping unaltered structures both G and HIS. The attachment HIS to occurs by π–π stacking HIS-aromatic residue with surface. This partially blocks pz electrons G, giving rise splitting valence conduction bands. Moreover, width directly...

The adsorption of five Nα-substituted amino acids with a 5-nitroso-6-oxo pyrimidine as substituent on commercial activated carbon (AC) has been studied in aqueous solution at several pH values. processes these organic compounds have analyzed the basis electrolytic behavior adsorbates. In all cases, process is highly irreversible due to strong π−π interactions between arene centers AC and residue This interaction consistent XPS data HOMO−LUMO theoretical calculations. provides new route for...

The binding properties of HL1, HL2, and HL3 ligands toward Cu(II) Zn(II) ions, constituted by tetraaza-macrocyclic rings decorated with pyrimidine pendants, were investigated means potentiometric UV spectrophotometric measurements in aqueous solution, the objective using related HL-M(II) (HL = HL1-HL3; M Cu, Zn) complexes for preparation hybrid MWCNT-HL-M(II) materials based on multiwalled carbon nanotubes (MWCNTs), through an environmentally friendly noncovalent procedure. As shown crystal...

A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, water at room temperature, of macrocyclic H2L ligand on graphene (G) (G + = G-(H2L)), followed by decoration macrocycle with Pd2+ ions (G-(H2L) G-(H2L)-Pd) under same mild conditions. This supramolecular approach is sustainable (green) procedure that preserves special characteristics and furnishes an efficient for Cu-free Sonogashira cross coupling reaction between...

The synergistic action of the different binding groups polyfunctional HL receptor leads to recognition ADP over ATP in water, with a selectivity coefficient up 116, phenomenon which is unprecedented context synthetic receptors water. mostly due good matching between H3L2+ and protonated forms ADP.

Abstract The compound N ‐(4‐amino‐1‐methyl‐5‐nitroso‐6‐oxo‐1,6‐di‐hydropyrimidin‐2‐yl)‐ '‐[bis(2‐aminoethyl)]ethylenedi‐amine (HL) was synthesised and structurally characterised by analytical methods 1 H, 13 C 15 NMR spectroscopy. protonation of HL its coordinating ability towards Zn 2+ Cd ions in water solution were also studied potentiometric UV/Visible H‐ molecular structures [H 3 L] [CdI 4 ] 2– · 2H 2 O [(Cl Zn)(μ‐Cl){Zn(μ ‐HL)}] 2.5H solved single‐crystal X‐ray diffraction methods. On...

The interaction of AMP, ADP, ATP and related phosphate, diphosphate triphosphate anions with the positively charged forms HL ligand, constituted by a tren molecule functionalized pyrimidine residue, was studied potentiometric titrations, affording stability constants formed anion complexes, 31P 1H NMR spectroscopy in aqueous solutions modelling calculations. equilibrium data show that electrostatic forces make an important, but not decisive contribution, to complexes. For nucleotides,...

Abstract The new compound N ϵ ‐(4‐amino‐1,6‐dihydro‐1‐methyl‐5‐nitroso‐6‐oxopyrimidin‐2‐yl)‐ L ‐lysine (H 2 L) has been synthesised and its molecular structure determined by single‐crystal X‐ray diffraction methods. Brönsted acid/base character of H in water the pH range 2.5–10.0, nature observed protonation steps potentiometric spectrophotometric adsorption on a commercial activated carbon (AC) aqueous solution is irreversible, mainly due to electronic behaviour π system pyrimidine moiety....

The coordination features of the three dipyridine-containing polyamine macrocycles 2,5,8,11,14-pentaaza[15]-[15](2,2')[1,15]-bipyridylophane (L1), 5,8,11-trimethyl-2,5,8,11,14-pentaaza[15]-[15](2,2')[1,15]-bipyridylophane (L2), and 4,4'-(2,5,8,11,14-pentaaza[15]-[15](2,2')-bipyridylophane) (L3) toward Cd(II) Pb(II) have been studied by means potentiometric, microcalorimetric, spectrophotometric UV−vis titrations in aqueous solutions. All ligands form 1:1 metal complexes. In L1 L2 complexes...

In each of N-(6-amino-3, 4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)valine, C(10)H(15)N(5)O(4) (3) (orthorhombic, P2(1)2(1)2(1)), 4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)serine monohydrate, C(8)H(11)N(5)O(5).H(2)O (4) and 4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)threonine, C(9)H(13)N(5)O(5)(5) (monoclinic, P2(1)), the C-nitroso fragments exhibit almost equal C-N N-O bond lengths: range is 1. 315 (3)-1.329 A 1.293 (3)-1.326 A. compound there are also very short...

Nine hydrated complexes of Group 2 (alkaline earth) cations with organic ligands which are N-substituted amino acids containing the 6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl group have been structurally characterized. The octahydrated calcium glycinate complex, where six-coordinate Ca cation lies on an inversion centre in space P(-)1, forms a finite (zero-dimensional) complex. hexahydrated barium complex contains eight-coordinate Ba and it is isostructural known Sr analogue,...

Two novel hybrid catalysts have been prepared by anchoring Pd(<sc>ii</sc>)-amino complexes on the graphitic surface of ACs and their catalytic activities 1-octene hydrogenation are presented.