Valeria Amendola

Valeria Amendola
University of Pavia | UNIPV · Department of Chemistry

PhD

About

100
Publications
5,438
Reads
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5,462
Citations
Additional affiliations
May 2013 - June 2013
University of Zurich
Position
  • visiting scientist
May 2012 - June 2012
University of Zurich
Position
  • visiting scientist
August 2011 - September 2011
Technische Universität München
Position
  • visiting scientist

Publications

Publications (100)
Article
Two novel imide/imine‐based organic cages were prepared and studied as materials for the selective separation of CO 2 from N 2 and CH 4 in Vacuum Swing Adsorption conditions. Gas adsorption on the new compounds showed selectivity for CO 2 over N 2 and CH 4 . The cages were also tested as fillers in mixed‐matrix membranes for gas separation. Dense a...
Article
A chiral cage is proposed as an effective chiroptical sensor for perrhenate (surrogate for 99TcO4-) in water, fruit juice and artificial urine medium. The key mechanism for the chiroptical sensing...
Article
Full-text available
Membrane-based processes are taking a more and more prominent position in the search for sustainable and energy-efficient gas separation applications. It is known that the separation performance of pure polymers may significantly be improved by the dispersion of suitable filler materials in the polymer matrix, to produce so-called mixed matrix memb...
Article
The extraction of technetium, present in nitric acid medium as pertechnetate anion, is an issue in solvent extraction processes used to recover uranium and plutonium. In the present study, a complexing agent is added in the aqueous nitric acid solution to bind selectively the pertechnetate anion and prevent its extraction into the organic phase or...
Chapter
This Chapter is focused on the major advances in the photophysics of transition metal complexes reported in the literature in 2019 and 2020. The metal species considered here belong to families of mono- and hetero-nuclear complexes containing d-block metal ions, spanning from earth abundant first row transition elements to coinage and platinum grou...
Article
We report the investigation of dicopper(II) bistren cryptate, containing naphthyl spacers between the tren subunits, as a receptor for polycarboxylates in neutral aqueous solution. An indicator displacement assay for dicarboxylates was also developed by mixing the azacryptate with the fluorescent indicator 5-carboxyfluorescein in a 50:1 molar ratio...
Article
Benzene is a highly toxic aromatic hydrocarbon. Inhaling benzene can cause dizziness, vertigo, headaches, aplasia, mutations and, in the most extreme cases, cancer. Trans, trans‐muconic acid (t,t‐MA) is one of the metabolization products of benzene. Although different analytical methods have been reported for the determination of t,t‐MA, these are...
Article
The research of systems able to perform controllable motions under external stimuli arises great interest from the scientific community. Over the years, a library of innovative devices have been produced, classified in different categories according to the molecular or supramolecular level of motion. This minireview is aimed to highlight some repre...
Article
Full-text available
In this work, we report the synthesis of a new bis(tris(2-aminoethyl)amine) azacryptand L with triphenyl spacers. The binding properties of its dicopper complex for aromatic dicarboxylate anions (as TBA salts) were investigated, with the aim to obtain potential building blocks for supramolecular structures like rotaxanes and pseudo-rotaxanes. As ex...
Preprint
div> The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous pha...
Article
Technetium is present as the pertechnetate anion in spent nuclear fuel solutions, and its extraction by several extractant systems is a major problem for the liquid-liquid extraction processes used to separate uranium and plutonium1. To prevent technetium extraction into the organic phase, a complexing agent may be added to the aqueous nitric acid...
Chapter
This Chapter aims at summarizing the major advances achieved, over 2017 and 2018, in the scope of the photophysics of d-block metals complexes. In the last years, one of the central research themes has been the development of luminescent complexes based on earth-abundant metal ions, which could effectively replace second and third-row transition-me...
Article
Herein, we present an example of covalent cages, whose flexible framework undergoes extending–shrinking motion under halide control. In absence of halide anions, the free cage assumes a flattened conformation: the cavity is compressed along the C3 axis passing through the tertiary amines, and the two tribenzylamine platforms are eclipsed. Halide en...
Article
Full-text available
A copper complex embedded in the structure of a water-soluble naphthalene diimide has been designed to bind and cleave G-quadruplex DNA. We describe the properties of this ligand, including its catalytic activity in the generation of ROS. FRET melting, CD, NMR, gel sequencing, and mass spectrometry experiments highlight a unique and unexpected sele...
Article
In this work, we combined smartphone sensing with the Indicator Displacement approach for the determination of trans,trans-muconic acid (i.e. tt-MA), a benzene biomarker, in urine. As receptor, a dicopper(II) azacryptate was employed. The good match of tt-MA with the receptor cavity was suggested by DFT calculations, and confirmed experimentally by...
Article
Novel pseudorotaxane structures have been obtained by using a bis[tris(2-aminoethyl)amine (tren)] azacryptand, copper(II) ions, and a dianionic molecular axle as the building blocks. The threading, occurring at pH 7 in a methanol/water mixture, is promoted by the strong binding of the axle’s dicarboxylate unit to the copper(II) centers within the a...
Article
In this work, we have investigated the properties of novel fluorescent semi(thio)carbazone systems with anions by UV-vis., spectrofluorimetric and NMR studies, in acetonitrile and DMSO solutions. Conformational preferences were determined by theoretical calculations within the DFT approach. For the free receptors, these studies pointed out a marked...
Article
In this work, we investigated the dicopper(II) complex of MozobilTM as a potential receptor for anions in MeOH and MeOH/water mixture. The results were compared with those obtained for the mononuclear complex, copper(II) benzyl-cyclam as a model system. Experimental investigations were also supported by computational studies on both the dinuclear a...
Article
This is a short overview on azacryptands, as molecular receptors for cations and anions. A particular attention was devoted to the results obtained by women researchers working in the field. The terms ‘cryptand’ and ‘cryptate’ were coined by Lehn. Since then, much work has been done to improve the knowledge on this class of receptors. Small azacryp...
Article
The new ligand L was prepared, featuring a 13-membered tetraaza macrocyclic ring and a 1,8-naphtalimide fluorophore appended on a C atom of its backbone. The protonation constants of L as well as its complexation constants with Zn2+ have been determined in 1:1 water:methanol solution by potentiometric titrations. pH-fluorimetric titrations have bee...
Article
Full-text available
For the first time, the tetrafluorobenzyl unit has been considered as a C-Hanion binding motif. In synergy with imidazolium groups within a bowl-shaped receptor, it has allowed for the effective binding of chloride in solution. Remarkable affinity was observed in organic-water mixtures.
Article
Novel tripodal 3-iodopyridinium-based receptors were investigated through (i) UV-vis and NMR titrations with anions in solution, (ii) theoretical calculations, and (iii) X-ray diffraction studies. Their anion binding properties were compared to those of the monobranched model and/or non-halogenated model systems. Investigations in acetonitrile poin...
Article
A new macrobicyclic ligand capable of binding two Cu2+ cations has been synthetized and its protonation and coordinative properties fully determined in aqueous solution. A thioether moiety was appended on the ligand backbone. This does not influence the ligand coordination ability but allows to graft its bis-copper complex on the surface of a self-...
Article
Full-text available
Mozobil(™) (1,1'-[1,4-phenylenebis(methylene)]bis[1,4,8,11-tetraazacyclotetradecane], , also known as JM3100 and AMD 3100) is a specific antagonist of the chemokine coreceptor CXCR4 and favours the mobilisation from the bone marrow of stem cells, which can be used for autologous transplantation. It is believed that the interaction, of both hydrogen...
Chapter
This chapter reviews the major advances in the field of photochemistry and photocatalysis by transition metal compounds published in 2013–2014. Particular attention has been given to (i) photocatalysis in synthesis, and in the conversion of sunlight energy into chemical energy; (ii) photoreactivity; (iii) biomedical applications of photoactive tran...
Article
Substituted and water-soluble naphthalene diimides (NDIs) exhibiting (CH2)2NMe2 coordinating moieties have been shown to be selective and fast responding mono- and di-nuclear colorimetric Cu(II) chemosensors.
Article
Full-text available
Bistren cryptands can be easily synthesised through Schiff base condensation of two molecules of tren and three molecules of a dialdehyde, followed by hydrogenation of the six C=N double bonds to give octamine cages, whose ellipsoidal cavity can be varied at will, by choosing the appropriate dialdehyde, in order to include substrate of varying size...
Article
From an EtOH/H2O solution, 0.3 M each of Ni2+ and cyclic triamine tacn (2; tacn=1,4,7-triazacyclononane), after 10 min refluxing and cooling at room temperature, copious and comparable amounts of blue crystals (containing the complex [Ni(tacn)(H2O)3]2+) and pink crystals (containing in the same cell both [Ni(H2O)6]2+ and [Ni(tacn)2]2+) precipitated...
Article
Full-text available
In this work, we report on two new asymmetric dicopper cryptates, characterized by alternate furanyl and p-xylyl spacers. The results of the potentiometric, UV-vis and X-ray diffraction studies are discussed. In particular, for one of the cages in the octaprotonated form, the crystal structure of the complex with nitrate is described. From the poin...
Article
Full-text available
The selective binding of 99 Tc pertechnetate (99 TcO 4 À) in water is a big challenge. Recently, our group reported on the p-xylyl aza-cryptand, as the first molecular receptor for 99 TcO 4 À in aqueous solution. Here, we show that the introduction of a fluorescent unit in the azacryptand's framework leads to a new molecular system, able to selecti...
Article
The anion binding tendencies of the two fluorogenic ureas L1H and L2H, containing the 2 anthracenyl and 1 pyrenyl moieties as signaling units, respectively, have been investigated in MeCN and DMSO by absorption, emission and 1H-NMR spectroscopies. The formation of stable 1:1 receptor:anion H bond complexes has been confirmed by structural studies o...
Article
The combined activity of the 1.1.1‐cryptand and of a dicopper(II) bistren cryptate complex including chloride makes the Cl− ion be continuously and slowly delivered to the solution, without any external intervention. The 1.1.1‐cryptand slowly releases OH− ions, according to a defined kinetics, and each OH− ion displaces a Cl− ion from the cryptate....
Article
Full-text available
New solid-phases for the binding, separation and extraction of perrhenate and pertechnetate (ReO(4)(-) and TcO(4)(-)) from water solutions have been developed from a selective molecular receptor. Host compounds being capable of encapsulating these oxoanions are of great interest. The azacryptand, containing two tripodal tetra-amine subunits covalen...
Article
Too hot to handle: Unprecedented affinity and specificity for 99TcO4− in aqueous solution was shown with the p-xylyl azacryptand in the hexaprotonated form (see scheme). A crystal structure of the complex reveals how the anion fits within the cavity of the cage, and the formation of multiple H-bond interactions with protonated amino groups stabiliz...
Article
Too hot to handle: Unprecedented affinity and specificity for (99) TcO(4) (-) in aqueous solution was shown with the p-xylyl azacryptand in the hexaprotonated form. A crystal structure of the complex reveals how the anion fits within the cavity of the cage, and the formation of multiple H-bond interactions with protonated amino groups stabilize the...
Article
he affinity of azacryptands towards perrhenate has been investigated by potentiometric, 1H NMR spectroscopic and ITC studies in aqueous solutions. The association constants could only be determined for the p-xylyl and m-xylyl azacryptands in the hexaprotonated form. The experimental results showed the outstanding affinity of the p-xylyl cryptand fo...
Article
Full-text available
The influence of the positively charged N-methylpyridinium substituent on the anion binding tendencies of urea-based receptors has been investigated by comparing molecules 1 and 2. These receptors have been studied in acetonitrile, by performing UV-vis. and (1)H NMR titrations with several anions. UV-vis. titrations have also been performed in DMSO...
Article
The trisbenzimidazolium cyclophane receptor 23+ incorporates the F– anion in MeCN solution, which was inferred by spectrophotometric and 1H NMR titration experiments, with an association constant log K > 7. On the basis of geometric considerations, it is assumed that F– lies in the middle of the triangle 3C, whose vertices are the carbon atoms of t...
Article
The tris-benzimidazolium cage LH(3)(3+), in MeCN solution, in the presence of OH(-), forms with Cu(I) and Ag(I) ions complexes of formula [M(I)(LH)](2+), in which each metal is linearly coordinated by two carbenes and one imidazolium N-H fragment remains intact. To achieve two-coordination, the two N-heterocyclic moieties of the cage make a saloon-...
Article
In this work, we compare the anion-binding capabilities of receptors 1-5, characterized by similar structures, but possessing different hydrogen-bond-donor moieties (urea, squaramide, and sulfonamide). The presence of chromophoric substituents on the receptor's skeleton allowed the determination of association constants by performing UV/Vis titrati...
Article
Since 1992 a variety of urea-based anion receptors have been synthesised, of varying complexity and sophistication. This critical review will focus on some distinctive aspects of anion recognition by urea derivatives, with a special reference to: (i) design and synthesis, (ii) methodologies for the investigation of the receptor-anion interaction in...
Article
The interaction of a neutral squaramide-based receptor, equipped with two 4-nitrophenyl substituents (Rsq), with halides and oxoanions has been studied in MeCN. UV/Vis and 1H NMR spectroscopy titration experiments clearly indicated the formation of 1:1 hydrogen bonding [R sq⋯X]+ complexes with all the investigated anions. X-ray diffraction studies...
Article
The racemic form of 5 ((RR)5 + (SS)5) gives dinuclear complexes of 2:2 stoichiometry both with Cu(II), acting as a bis-terdentate ligand, and with Cu(I), acting as a bis-bidentate ligand. Single crystal X-ray diffraction studies have shown that the Cu(II) complex exists as double-strand homochiral helicate molecules: P,P-[Cu(2)(II)((RR)5)(2)](4+) a...
Chapter
Introduction Ion Translocation Assembling/Disassembling of Helicate Complexes Driven by the CuI/CuIi Couple Concluding Remarks References
Article
The dimetallic cryptate [Cu(2)(II)(1)](4+) selectively recognizes guanosine monophosphate with respect to other nucleoside monophosphates (NMPs) in a MeOH/water solution at pH 7. Recognition is efficiently signaled through the displacement of the indicator 6-carboxyfluorescein bound to the receptor, monitoring its yellow fluorescent emission. Titra...
Article
Transition metals can be used as structural elements to build up anion receptors, enhancing H-bond donor tendencies, favouring the assembling of the molecular framework, inducing the formation of a cage. The versatile spectroscopic and electrochemical properties of the metal ion can provide a convenient signalling mechanism to communicate the occur...
Article
The terdentate ligand 3 (LH, 2-formylpyridine 4-thiosemicarbazone) forms with FeII and NiII 2:1 complexes of octahedral geometry of formula [MII(LH)2]2+. X-ray diffraction studies have shown that in both complexes the thiourea moieties of the coordinated thiosemicarbazones are exposed to the outside and are prone to establish hydrogen-bonding bifur...
Article
The inclusion of halide ions into a dicopper(II) bistren cryptate complex containing 2,5-dimethylfuran spacers has been investigated through spectrophotometric titration experiments in MeCN solution. X-ray diffraction studies on the 1:1 chloride inclusion complex have shown that the encapsulated halide ion and the furan oxygen atoms lie at an inter...
Article
A versatile example of a molecular machine is described. The stationary part is an iron protoporphyrin complex, bearing two movable side chains with terminal donor groups. Changing the pH or the electrochemical potential, as well as the injection of CO, alters the affinity of the donor groups toward the metal ion, thus promoting intra-molecular mot...
Article
The tripodal system [1]3+ forms a 1:1 complex with CoII in which the metal is octahedrally coordinated by three bpy fragments. The [CoII(1)]5+ complex provides a cavity suitable for solvent or anion inclusion. X-ray diffraction studies on the crystalline complex salt of formula [CoII(1)...H2O]Cl(PF6)(4).2MeCN have shown that a water molecule is inc...
Article
Dicationic ligands incorporating two 2,2'-bipyridine units and two imidazolium moieties, [1](2+) and [2](2+), form stable chelate complexes with Cu(II) and Cu(I) in acetonitrile solution. Each Cu(II) complex binds two X(-) ions according to two stepwise equilibria, the first involving the Cu(II) centre and the second involving the bis-imidazolium c...
Article
(Figure Presented) Sheltering under the roof: A trisimidazolium cage is capped with a {FeII(bpy)3}2+ subunit to produce a receptor that can bind small anions (bpy = 2,2′-bipyridine). Rodlike "pseudohalide" (N3-, NCO-, and NCS-) and spherical halide (Cl-, Br- and I -) anions accept hydrogen bonds from C-H fragments in the receptor cavity. The N3- io...
Article
1-(3-[1,10]phenanthrolin-2-yl-phenyl)-3-(4-trifluoromethyl-phenyl)-urea (1) forms a solution-stable 1:2 complex with copper(I), [CuI(1)2]+, which behaves as an anion receptor in aprotic media. The [CuI(1)2]+ receptor may adopt a geometrical arrangement in which the two facing urea subunits give tetrafurcate H-bond interaction with a spherical anion...
Article
Anions can be recognized by either positively charged or neutral artificial receptors. Positive charges within receptor's cavity can be provided by transition metal ions (e.g. CuII), which offer a binding site to one donor atom of the envisaged anion. Dicopper(II) bistren cryptates are ideal receptors for ambidentate anions, capable to bridge the t...
Article
Molecules containing polarized N-H fragments behave as H-bond donors toward anions and are widely used as receptors for recognition and sensing purposes in aprotic solvents (CHCl(3), MeCN, and DMSO). We present examples of receptors containing pyrrole and urea subunits, and we discuss the stability of their H-bond complexes with a variety of anions...
Article
Multicomponent systems have been designed, which are able to perform defined functions related to light emission and quenching. The desired function can be switched ON/OFF by the operator through a chemical input, either a change of pH or a variation of the redox potential. Transition metals (e.g. NiII, CuII) are key constituents within the conside...
Article
The heteroditopic receptors 1 and 2 firmly include an Ag(I) ion into the NS2O2 crown and establish selective H-bond interactions with anions at the covalently linked urea/thiourea (U/T) subunit. Studies in MeCN solution showed that the metal center induces a 10(3)-10(6)-fold enhancement of the anion association constant, due to a coordinative inter...
Article
The trifurcate receptor 1(3+) forms stable 1:1 complexes with halide and oxo anions in MeCN solution, as shown by spectrophotometric and 1H NMR experiments, and selectively recognizes chloride (lg K(ass) > 7) in the presence of fluoride and bromide. The high stability reflects the receptor's ability to donate up to six hydrogen bonds (from three py...
Article
The binding tendencies of the enantiomeric forms, R,R and S,S, of the neutral receptor 1 towards anions were investigated through UV-vis and 1H NMR titration experiments in DMSO. Both enantiomers form stable H-bond complexes with carboxylates and phosphates. In particular, receptor 1 strongly binds two H2PO4- ions according two stepwise equilibria,...
Article
When the amide-containing receptor 1(+) is in a solution of dimethyl sulfoxide (DMSO) in the presence of basic anions (CH(3)COO(-), F(-), H(2)PO(4) (-)), it undergoes deprotonation of the -NH fragment to give the corresponding zwitterion, which can be isolated as a crystalline solid. In the presence of less basic anions (Cl(-), Br(-), NO(3) (-)), 1...
Article
Three-component systems made of a tetradentate bis-amino bis-quinoline ligand, a transition metal cation (Ni2+ or Cu2+) and a fluorescent indicator (Coumarin 343) have been studied in a water-dioxane (1 : 4 v/v) mixture, through potentiometric, pH-spectrophotometric and pH-fluorimetric titrations. For the Cu2+ containing systems, an "on-off-on" var...
Article
A new approach based on self-assembly inside micelles has been individuated to prepare a system behaving as a water-operating selective fluorescent sensor for Cu2+ and Ni2+.
Article
The ligand 2, in which three fluorogenic 6-methoxy-1-methylquinolinium fragments are appended to a mesityl platform, in MeCN forms 1:1 adducts with halides and other inorganic anions. (1)H NMR studies and molecular modelling indicate that 2 provides a cavity for anion inclusion and establishes electrostatic interactions with the guest. Anion inclus...
Article
The tetradentate ligands tcp and ccp, made of two bidentate iminophenanthridine halves, separated, respectively, by trans- and cis-cyclohexanediyl spacers, have been studied in acetonitrile as regards their ability of coordinating the d10 cations Ag+ and Zn2+. Spectrophotometric and spectrofluorimetric titrations revealed the tendency to form 1 ∶ 2...
Article
The new ligands R,R-trans-S,S'-bis[methyl(2'-quinolyl)]-1,2-dithiacyclohexane, cis-S,S'-bis[methyl(2'-quinolyl)]-1,2-dithiacyclohexane, and 1,6-bis(2'-quinolyl)-2,5-dithiahexane have been synthesized and their complexes with Cu(I) and Cu(II) prepared. The ligand/metal systems are bistable, as the complexes with copper in both its oxidation states a...
Article
The bis-bidentate ligand R,S-1,2-diphenyl-N,N′-bis(2- quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With Cu I and o...
Article
The fac-Re(CO)3(bipy-COOH)Cl complex (bipy=2,2′-bipyridine) bears a carboxylic function in the 5-position of the bipy ligand: due to the kinetic inertness of the ReI center, the complex behaves as a R-COOH carboxylic acid. In aqueous solutions, it coordinates Cu2+, according to pH-dependent equilibria, to give the dimeric species Cu[fac-ReI(CO)3(bi...
Article
The assembly/disassembly of a dicopper(I) helicate with a bis-bidentate imine-quinoline ligand is driven by the Cu(II)/Cu(I) redox change and is signaled by a fluorescent probe bearing a -COO(-) group (coumarine 343). The probe coordinates the Cu(II) center of the monomeric complex, which quenches its emission (fluorescence off), and is released up...
Article
The formation of a dicopper(I) helicate by performing oxidative dehydrogenation of a monomeric polyamine complex [CuII(1)] 2+ with OH- and O2 was investigated. The process involved the deprotonation of the amine groups coordinated to Cu II, their oxidative dehydrogenation to imine. The temporal development of the band at 530 nm for a solution adjus...
Article
By reaction of the bis-bidentate imino-quinoline ligand 1 with the octahedral cation Fe2+ in a 3 : 2 metal/ligand molar ratio, a partial hydrolysis of the ligands is observed instead of the formation of the expected triple helicate, due to the excessive crowding of the trans-1,2-cyclohexyl spacers. The monomeric [Fe-II(2)(2)](2+) complex is obtaine...