Enrico Dalcanale

Università di Parma | UNIPR · Department of Chemistry

For their great structural versatility, thiophene-based π-conjugated systems have been widely exploited in the preparation of low band gap materials. Here, we report the synthesis of a highly conjugated tetrathiophene system, namely 1,4-di([2,2′-bithiophen]-3-yl)buta-1,3-diyne (1), that presents two bithiophene units connected at position 3 by a bu...

Post‐translational modifications of lysine in histones, as methylation and acetylation, have well established functions in epigenetics and are emerging as important actors in broader biological regulation. Currently, the detection of acetylated lysine (Kac) in water solution as free amino acid or protein residue remains challenging. Acetylated lysi...

Nearly every protein in the human body is modified with post-translational modifications (PTMs). PTMs affect proteins on many levels, including their function, interaction, half-life, and localization. Specifically, for histone proteins, PTMs such as lysine methylation and acetylation play essential roles in chromatin dynamic regulations. For this...

The current work focuses on the investigation of two functionalized naphthyridine derivatives, namely ODIN‐EtPh and ODIN‐But, to gain insights into the hydrogen bond‐assisted H‐aggregate formation and its impact on the optical properties of ODIN molecules. By employing a combination of X‐ray and electron crystallography, absorption and emission spe...

Auxetics are materials characterized by a negative Poisson's ratio (NPR), an uncommon mechanical behavior corresponding to a transversal deformation tendency opposite to the traditional materials. Here, the first example of a synthetic molecular auxetic polymer obtained by embedding a conformationally expandable cavitand as a crosslinker into a rig...

Polyethylene based ionomers are demonstrated to feature a thermo‐mechanical and dielectric property portfolio that is comparable to cross‐linked polyethylene (XLPE), which may enable the design of more sustainable high voltage direct‐current (HVDC) power cables, a crucial component of future electricity grids that seamlessly integrate renewable sou...

Auxetics are materials characterized by a negative Poisson’s ratio (NPR), an uncommon mechanical behavior corresponding to a transversal deformation tendency opposite to the traditional materials. Here we present the first example of a 3D synthetic molecular auxetic polymer, obtained by embedding a conformationally expandable cavitand as crosslinke...

In this study, we present two-photon microscopy (2PM) as an original technique to investigate the compatibilization between PE-HEMA and EVOH at the sub-micrometer level, both on the surface and in the bulk. 2PM is a nonlinear fluorescence imaging technique commonly exploited for thick biological tissue analysis. Here, we use 2PM to visualize polyme...

The dynamic behavior of supramolecular organic frameworks (SOFs) based on the rigid tetra‐4‐(4‐pyridyl)phenylmethane (TPPM) organic tecton has been elucidated through 3D electron diffraction, X‐ray powder diffraction and differential scanning calorimetry (DSC) analysis. The SOF undergoes a reversible single‐crystal‐to‐single‐crystal transformation...

We report a strategy for the realization of NMR chemosensors based on the spontaneous self-assembly of lower rim pyridinium-functionalized tetraphopshonate cavitands on commercial silica nanoparticles. These nanohybrids enable the selective...

The selectivity and efficiency of benzene and toluene uptake at the gas-solid interface by quinoxaline cavitands is strongly enhanced by partial rigidification of the receptor cavity and immobilization of the cavitand onto silica gel particles.

The monitoring of benzene and other carcinogenic aromatic volatile compounds at the ppb level requires boosting both the selectivity and sensitivity of the corresponding sensors. A workable solution is the introduction in the devices of preconcentrator units containing molecular receptors. In particular, quinoxaline cavitands (QxCav) resulted in ve...

A very sensitive and selective solid-phase microextraction-gas chromatography-mass spectrometry method based on the use of a deep cavity BenzoQxCavitand as innovative coating was developed and validated for the simultaneous determination of the 16 US-EPA priority pollutants polycyclic aromatic hydrocarbons (PAHs) in snow samples at ultra-trace leve...

Inclusion of polymethine cyanine dyes in the cavity of macrocyclic receptors is an effective strategy to alter their absorption and emission behavior in aqueous solution. In this paper, the effect of the host‐guest interaction between cucurbit[8]uril (CB[8]) and a model trimethine indocyanine (Cy3) on dye spectral properties and aggregation in wate...

Mechanochemical synthesis is an attractive preparative method that combines a green approach with versatility, efficiency, and rapidity of reaction. However, it often yields microcrystalline materials, and their small crystal size is a major hindrance to structure elucidation with conventional single-crystal or powder X-ray diffraction methods. Thi...

The removal of toxic and carcinogenic polycyclic aromatic hydrocarbons (PAHs) from water is one of the most intractable environmental problems nowadays, because of their resistance to remediation. This work introduces a highly efficient, regenerable membrane for the removal of PAHs from water, featuring excellent filter performance and pH‐driven re...

The host–guest inclusion complexes of cucurbiturils with alkyl viologen have interesting architectures, chemical properties, and potential applications in sensors and nanotechnology. A highly hydrated triclinic crystal of cucurbit[8]uril (CB[8]) complexed by methyl hexadecyl viologen (MVC16) is characterized by the unprecedented coexistence in the...

The unique temperature, solvent and pH drivenvase to kite equilibrium in quinoxaline cavitands allows the reversible uptake and release of guests. However, the cavity breathing associated with this conformational switch reduces the strength of complexation. A limited number of solutions have been proposed for the cavity rigidification, using either...

The secondary structures of nucleic acids have an important influence on their cellular functions but can be difficult to identify and classify quickly. Here, we show that an arrayed suite of synthetic hosts and dyes is capable of fluorescence detection of oligonucleotide secondary structures. Multivariate analysis of different fluorescence enhance...

Viologens are among the most studied guests for cucurbit[8]uril (CB[8]) and their complexation is usually driven by bipyridyl core inclusion inside the cavity to maximize both hydrophobic and cation‐dipole interactions. The presence of alkyl substituents on the guest alters this complexation mode, switching to aliphatic chain inclusion in U‐folded...

The formation of supramolecular structural units through self‐assembly is a powerful method to design new architectures and materials endowed with specific properties. With the aim of adding a group of versatile tectons to the toolkit of crystal engineers, we have devised and synthesised four new V‐shaped building blocks characterised by an aryl ac...

There is considerable interest in dynamic materials featuring modular components with nano-scale dimensions and controlled responsiveness to external stimuli. Supramolecular polymers are a class of materials that fulfil all these conditions well. Here, we present a family of host–guest supramolecular polymers that combine the outstanding complexing...

This study focuses on the influence of biochar – a solid, porous, carbonaceous material product resulting from biomass gasification of wood waste – on mechanical properties of cement mortars. In order to investigate its effectiveness for structural purposes, biochar is added in cement mortar in increasing percentages, up to 2.5% by weight of cement...

Functional polyethylene (PE) bearing pendant hydroxyl groups was dynamically crosslinked via reactive extrusion using commercially available N,N′-Bis[3-(trimethoxysilyl)propyl] ethylenediamine (TMSPEDA). This fast and efficient way allowed to produce PE vitrimers without synthetic effort or use of solvent, which makes the process environmentally fr...

Abstract The eligibility of tetraquinoxaline cavitands (QxCav) as molecular grippers relies on their unique conformational mobility between a closed (vase) and an open (kite) form, triggered in solution by conventional stimuli like pH, temperature and ion concentration. In the present paper, the mechanochemical conformational switching of ad hoc fu...

Vitrimers are an emerging class of permanently cross-linked materials, where exchange reactions of cross-links provide malleability. The most promising application of these materials is to impart reprocessability to thermoset polymers, such as cross-linked polyethylene (PE). Here, a facile and easy to scale-up method for the preparation of cross-li...

The ability to detect early damage is of great significance in load bearing composite materials used for high performance applications. Microdamages if left unchecked can grow under subsequent stress, leading to catastrophic structural failure. The sensing of early stage damage via nondestructive methods is therefore critically important for the sa...

Stimuli-responsive supramolecular assemblies are dynamic systems that can reversibly switch between different states upon external stimuli. In this context, metal coordination offers a reliable strategy for the preparation of stimuli responsive supramolecular architectures. Herein we report the preparation of a solvent-responsive cavitand-lanthanum...

Velcrands are a specific class of cavitands whose complementary surfaces induce self-dimerization. The insertion of a velcrand as physical cross-linking unit into a polymer is reported. To this purpose, the velcrand was functionalized at the lower rim with an isocyanate group. The functional velcrand was reacted with poly (ethylene-co-(2-hydroxethy...

Ureidopyrimidinone (UPy) is introduced into various polyethylenes (Pes) bearing hydroxyl groups by solution grafting, affording physically cross-linked PE via multiple H-bonding. Utilizing low melting UPy where the methyl group is substituted with isopropyl (isopropyl UPy, IPR-UPy), a reactive extrusion process is developed that allows to significa...

We report the synthesis of a new macrocyclic receptor, namely 2,8,14,20-tetra­hexyl-4,24:6,10:12,16:18,22-O,O′-tetra­kis­[2,3-di­hydro-[1,4]dioxino[2,3-g]quinoxalin-7,8-di­yl]resorcin[4]arene, DeepQxCav, obtained by the addition of ethyl­ene glycol di­tosyl­ate to an octa­hydroxy quinoxaline cavitand. A 1:1 supra­molecular complex of this cavitand...

Crystallization of tetraphosphonate cavitand Tiiii[H, CH3, CH3] in the presence of positively charged amino acids, namely arginine, lysine, or histidine, afforded host-guest complex structures. The X-ray structure determination revealed that in all three structures, the fully protonated form of the amino acid is ditopically complexed by two tetraph...

High Density and Very Low Density PolyEthylene-graft-Maleic AnHydride (HDPE-MAH and VLDPE-MAH respectively) functionalized with 1-aminopyrene (AP) are prepared via reactive extrusion. Covalent attachment of AP is confirmed by lack of residual free AP after extraction with dichloromethane. Differential scanning calorimetry, tensile test, dynamical m...

Two synthetic protocols for the introduction of fluorine atoms into resorcinarene-based cavitands, at the lower and upper rim, respectively, are reported. Cavitand 1, bearing four fluorocarbon tails, and cavitand 2, which presents a fluorine atom on the para position of a diester phosphonate phenyl substituent, were synthesized and their complexati...

Multiple hydrogen bonding motifs are promising tools for polymer functionalization to obtain adaptable networks combining advantages of permanently cross-linked systems with processability of thermoplastics. Here we describe the use of a new multiple hydrogen bonding motif to impart increased tensile strength, stiffness, barrier properties, and a p...

Preventive healthcare asks for the development of cheap, precise and non-invasive sensor devices for the early detection of diseases and continuous population screening. The actual techniques used for diagnosis, e.g. MRI and PET, or for biochemical marker sensing, e.g. immunoassays, are not suitable for continuous monitoring since they are expensiv...

Nanocolumnar Si substrates (porous silicon (PSi)) have been functionalized with a quinoxaline-bridged (EtQxBox) cavitand in which the quinoxaline moieties are bonded to each other through four ethylendioxy bridges at the upper rim of the cavity. The receptor, which is known to selectively complex aromatic volatile organic compounds (VOCs) even in t...

A study leading to the development of a piezoelectric sensing device for environmental monitoring of aromatic micropollutants in water is reported. A Piezoelectric Quartz Crystal (PQC) was functionalized through electropolymerization of a quinoxaline cavitand, known to possess remarkable capabilities in selectively trapping aromatic compounds throu...

While pH-driven interconversion of tetraquinoxaline cavitands (QxCav) from vase to kite conformation has been extensively studied both in solution and at interfaces, cavitands behavior in solid matrices is still unexplored. Therefore, the synthesis of a new class of quinoxaline cavitand based copolymers is here reported; a soluble linear poly(butyl...

A micro-electro-mechanical system (MEMS) based pre-concentrator filled with a standard Tenax TA adsorbent as well as with a synthetic receptor designed to adsorb 3-hydroxy-3-methylhexanoic acid (3H3MHA), a particular metabolite only available from human beings, was adapted to a custom made ion mobility spectrometer with gas-chromatographic pre-sepa...

Reliable chemical sensors with high selectivity and sensitivity toward specific target molecules require rational synthesis of receptors, in-depth characterization of their complexation abilities and highly efficient transduction of the molecular recognition event. Here we report a steady-state and time-resolved fluorescence investigation of EtQxBo...

Active materials are those capable of giving some physical reaction under external stimuli coming from the environment such as temperature, pH, light, mechanical stress, etc. Reactive polymeric materials can be obtained through the introduction of switchable molecules in their network, i.e. molecules having two distinct stable conformations: if pro...

Here, we provide the first structural characterization of host‐guest complexation between cucurbit[7]uril (Q7) and dimethyl‐lysine (KMe2) in a model protein. Binding was dominated by complete encapsulation of the dimethylammonium functional group. While selectivity for the most sterically accessible dimethyllysine was observed both in solution and...

Here, we provide the first structural characterization of host‐guest complexation between cucurbit[7]uril (Q7) and dimethyl‐lysine (KMe2) in a model protein. Binding was dominated by complete encapsulation of the dimethylammonium functional group. While selectivity for the most sterically accessible dimethyllysine was observed both in solution and...

Last advances and emerging strategies in environmental gas and vapor sensing conducted using molecular receptors, are presented. In particular, the use of these macrocycles as selective units to be integrated into portable devices for environmental monitoring is highlighted. For more details, see the Review article by R. Pinalli et al. on page 1010...

The properties of two inherently chiral cavitands in enantioselective recognition of N-methyl-leucine was studied in solution, through ¹H and ³¹P NMR experiments, and in the solid state, through co-crystallisation experiments. The inherent chirality of the receptors was obtained through the desymmetrization of the rigid concave cavity by introducin...

The complexation between 2-ureido-4[1H]-pyrimidinone (UPy) and 2,7-diamido-1,8-naphthyridine (NaPy) is used to promote the mild chemisorption of a UPy-functionalized terbium(III) double decker system on a silicon surface. The adopted strategy allows the single-molecule magnet behavior of the system to be maintained unaltered on the surface.

Environmental gas sensing needs stringent sensor requirements in terms of sensitivity, selectivity and ruggedness. One of the major issues to be addressed is combining in a single device the conflicting requirements of molecular-level selectivity and low-ppb sensitivity. The exploitation of synthetic molecular receptors as sensing materials is part...

The synthesis and the chemisorption from solution of a terbium bis-phthalocyaninato complex suitable for the functionalization of lanthanum strontium manganite (LSMO) are reported. Two phosphonate groups are introduced in the double decker structure in order to allow the grafting to the ferromagnetic substrate actively used as injection electrode i...

Solid-phase microextraction and gas chromatography-mass spectrometry followed by multivariate data analysis were used to analyze lung tissues from both healthy and carcinogenic patients. A total of 78 volatile compounds belonging to different chemical classes were identified, seven of which were able to discriminate between the two groups. Discrimi...

Advanced applications, involving high risk mechanical systems, require to verify the in-service deformation level in order to assess their safety and reliability, providing information for repairing or replacing interventions. In the present work, a self-diagnostic PDMS elastomer containing a supramolecular detection probe is proposed, enabling to...

A new inherently chiral cavitand is described, in which the desymmetrization of the rigid concave cavity is achieved by introducing three different bridging groups at the upper rim, namely two inward P=O groups, one inward P=S moiety and one methylene bridge in the AABC mode. The racemic mixture of cR and cS enantiomers is resolved by semi-preparat...

Binder and effector molecules that allow studying and manipulating epigenetic processes are of biological relevance and pose severe technical challenges. We report the first example of a synthetic receptor able to recognize mono-methylated lysines in a histone H3 tail peptide, which has relevant function in epigenetic regulation. Recognition is rob...

Two new complexes formed by tetraphosphonate cavitands with lead and copper salts, respectively, have been prepared and characterized in the solid state through X-ray diffraction analysis. In both cases, dimeric capsules are obtained, whose architecture depends on the cation dimensions: the coordination of the phosphonate groups to the metal center...

In this work we report a comprehensive study leading to the fabrication of a prototype sensor for environmental benzene monitoring. The required high selectivity and ppb-level sensitivity are obtained by coupling a silicon-integrated concentration unit containing the specifically designed EtQxBox cavitand to a miniaturized PID detector. In the resu...

We present here a reaction scheme to connect TbPc2 single-molecule magnets into 1D architectures using acyclic diene metathesis. To investigate the impact of the bonding through aliphatic chains on the magnetic properties of TbPc2, we isolate and characterize the dimeric species obtained as one of the products of the reaction. Remarkably, the magne...

Review: “classic” and recent results concerning their chemistry, applications and crysal structure; 128 refs.

A redox activated vase-to-kite conformational change is reported for a new resorcinarene-based cavitand appended with four quinoxaline-fused thianthrene units. In its neutral state, the thianthrene-containing cavitand was shown by ¹H NMR to adopt a closed vase conformation. Upon oxidation the electrostatic repulsion among the thianthrene radical ca...

Since their first appearance in the chemistry scene thirty years ago, resorcinarene-based cavitands have been recognized to be a highly versatile class of compounds. Endowed with a rigid cavity of molecular dimensions, which can be decorated at the upper and lower rims with a variety of functional groups, they are efficient molecular receptors for...

Molecular recognition is among the most important chemical events in living systems and has been emulated in supramolecular chemistry, driven by chemical and biochemical sensing potential. Identifying host-guest association in-situ at the interface, between the substrate-bound receptors and the analyte-containing media, is essential to predict comp...

We report on the eligibility of tetraphosphonate resorcinarene cavitands for the molecular recognition of amino acids. We determined the crystal structure of thirteen complexes of the tetraphosphonate cavitand Tiiii[H, CH3, CH3] with amino acids. 1H and 31P NMR experiments and ITC analysis were performed to probe the binding between cavitand Tiiii[...

A hierarchical hybrid inorganic-organic system suited for the recognition of aromatic volatile organic compounds (VOC) on brush-like ZnO fibers was synthetised. The hybrid material was obtained by a multi-step approach based on the growth of ZnO nanorods onto electrospun ZnO fibers (average diameter 200 nm). The obtained nanostructured ZnO brush-li...

Controlled phase separation in a polymer film, with subsequent morphology rearrangement on the micro-scale, provides novel perspectives in smart materials. Based on our experience on supramolecularly compatibilised polymer blends consisting of polystyrene and poly(butylmethacrylate), we demonstrate here physical segregation of the blend in the soli...

Here, we present a modular indicator-displacement-assay able to selectively recognize small molecules with biological relevance under competitive conditions. The assay relies on the change in affinity of macrocyclic receptors, such as cavitands, cyclodextrins or calixarenes, for monolayer protected gold nanoparticles upon complexation of the respec...

The complexation of L-Lactic acid by two isomeric di-phosphonate cavitands was studied, both in solution and in the solid state. 1H and 31P NMR experiments and X-ray diffraction analysis on single crystals evidenced the formation of a supramolecular host-guest adduct with both synthetic receptors, driven by a combination of H-bonding and C-H•••π in...

Two novel triptycene quinoxaline cavitands (DiTriptyQxCav and MonoTriptyQxCav) have been designed, synthesized, and applied in the supramolecular detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air. The complexation properties of the two cavitands towards aromatics in the solid state are strengthened by the presence of the tripty...