Giovanni Predieri

University of Parma | UNIPR · Department of Chemistry

This research deals with the use of water soluble polyamidoamines (PAAOH’s) as innovative paper preservatives endowed with deacidification and biostatic properties. They were obtained by reaction of N,N-methylenbisacrylamide (MBA) with ethanolamine (EA) and were characterized by Fourier Transform Infrared Spectroscopy analysis (FTIR), Electrospray...

Crystal structure prediction is the holy grail of crystal engineering and is key to its ambition of driving the formation of solids based on the selection of their molecular constituents. However, this noble quest is hampered by the limited predictability of the incorporation of solvent molecules, first and foremost the ubiquitous water. In this co...

Linear poly(amidoamine)s (PAAs), functionalized in the main chain with hydroxyl and/or siloxane groups, were obtained by single step addition of primary amines (ethanolamine, 3-aminopropyltriethoxysilane) to N,N’-methylenebisacrylamide, in water or low molecular weight alcohols, without catalysts. The polymers were characterized by FTIR, Raman, ¹H...

A new approach to the conservation of paper manuscripts is proposed that leads to both deacidification and strengthening of paper. The study was carried out by using polyamidoamines (PAAOHs) functionalized with alcoholic groups, in their native form (PAAb) or neutralized with boric acid (PAAn). They were applied on model paper samples containing ir...

The evaluation of conservative treatments’ efficacy on natural building stones are usually based on standard recommendation routines finalized to evaluate compatibility and harmfulness of products in turn of the substrate. However, the visualization and the quantification of products inside pore structure of natural stones is not immediate through...

The efficiency of a hybrid patented consolidant (PAASi) and two commercially available hybrid coatings (a consolidant named AlSiX and a hydrophobic product named WS3) properly modified was assessed on a calcarenite substrate. Test routines based on standard recommendations were first applied to evaluate the performances of the consolidant and prote...

Novel bio-inspired materials derived from crystalline nanocellulose (CNC) have been tested as wood consolidants. A suspension of CNC, produced by acid hydrolysis of cellulose and used as such or mixed with lignin and/or siloxane derivatives (PDMS), was applied on rotted wood samples of Norway spruce. X-Ray diffraction analysis on CNC powder showed...

Single crystals of Na[VO(SeO3)(HSeO3)]·1,5H2O have been prepared by solvent slow evaporation from an equimolar aqueous mixture of sodium selenite and vanadyl sulfate. The overall arrangement consists of VO6 octahedra, [SeO3]2− and [HSeO3]− anions forming a strong backbone with channel-like voids, while sodium cations participate in the framework, e...

Two unprecedented solid phases involving the 3,7-bis­(di­methyl­amino)­pheno­thia­zin-5-ium cation, i.e. methyl­ene blue (MB⁺), have been obtained and structurally characterized. In the crystals of 3,7-bis­(di­methyl­amino)­pheno­thia­zin-5-ium chloride dihydrate, C16H18N3S⁺·Cl⁻·2H2O (I) and 3,7-bis­(di­methyl­amino)­pheno­thia­zinium bis­ulfite, C...

Cu(II) cations in the presence of diamine ligands such as tetramethylethylendiamine (TMEDA) react with Na2SeO3 to produce the heteroleptic selenite copper compound of formula [Cu3(TMEDA)3(SeO3)2(H2O)4](NO3)2. In the cationic moiety two copper atoms are linked by two selenite anions through the O–Se–O bridge. One of the two bridging selenite anion c...

Accelerated weathering of polymethylmethacrylate (PMMA) and of hybrid PMMA/SiO2/ZrO2 films was monitored by spectroscopic, thermal and colorimetric measurements. The hybrid polymers were obtained by sol-gel process adding tetraethylorthosilicate (TEOS) and zirconyl chloride (ZrOCl2*8H2O) to a solution of PMMA. Photo ageing tests on polymeric films...

Metal-Organic Frameworks (MOFs) are crystalline porous materials in which organic coordinatively active molecules bridge together metal centers or assemblies resulting in a three-dimensional periodic network. One of the most undisputable advantages of MOFs lies in the possibility to design the organic linkers and choose the metals that will form th...

Questo articolo si propone come un account, un resoconto dell'attività svolta nell'ultimo quinquennio dal gruppo di ricerca del prof. Predieri nel Dipartimento SCVSA UniPR (Dipartimento di Chi-mica, fino al 2016) e tesa a sviluppare materiali so-stenibili per la conservazione (restauro sostenibile [1]) di manufatti ligno-cel-lulosici. I risultati o...

The ordered porosity of Metal Organic Frameworks is commonly acknowledged as the most important feature when their use in the field of host guest materials chemistry is concerned. This is indeed one of their main application, and the possibilities offered by their crystalline nature for structural studies concerning the trapped species make these m...

The study evaluated copper, boron, and silicon release from wood samples treated with sol-gel formulations based on tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) functionalized with copper (II) chloride and boric acid, respectively. The adopted leaching procedure was Japanese protocol JIS K 1571 (2004). Inductively Coupled Plasm...

Metal Organic Frameworks are one of the most popular examples of crystalline functional materials. Their applications, which often rely on their tuneable porosity, catch the interest of different branches of science, e. g. pharmaceutical, environmental and energetic chemistry. On the other hand, a post synthetic modification of the as-synthesized s...

The aromatic methylene blue cation (MB(+)) shows unprecedented ligand behavior in the X-ray structures of the trigonal-planar (TP) complexes MBMCl2 (M = Cu(I), Ag(I)). The two isostructural compounds were exclusively synthesized by grinding together methylene blue chloride and MCl solids. Only in the case of AuCl did the technique lead to a differe...

Three amidoamines containing the N-hydroxyethyl group (HOEt), namely (HOEt)2N(CH2)2C(O)NH2 (1), [(HOEt)2N(CH2)2C(O)NH]2CH2 (2) and HOEtN[(CH2)2C(O)NH2]2 (3) have been synthesized by reacting diethanolamine HOEt2NH with acrylamide and N,N′-methylenebisacrylamide (respectively 1 and 2) and ethanolamine HOEtNH2 with acrylamide (3). Four other compound...

Hybrid inorganic–organic treatments, based on amide-amine polymers (PAAs), against thermal oxidation have been prepared on paper dating back to eighteenth century. The polymeric sols are obtained by step-growth Michael addition polymerization and functionalized with siloxane network by sol–gel method. Five types of samples have been prepared changi...

Building materials undergo degradation caused by pollutant agents. Different solutions are proposed for the preservation of building façades: one of them is to modify their surface in order to confer self-cleaning properties, that are obtained by superhydrophobic treatments or by use of photo-catalytic materials. This work describes the synthesis o...

Methylene blue cation (MB) is a +1 charged heteroaromatic molecule whose spectroscopic, redox and medical properties are widely known and exploited in many research fields. Although the general interest, the major part of scientific research often focused on its behaviour in solution and the solid state chemistry of this molecule received only a sm...

Metal Organic Frameworks (MOFs) possess unique advantages among porous materials. They can be grown as single crystals and used as crystalline sponges, thanks to the cavities they exhibit. The periodic order of these solids could also allow in principle to use X-ray crystallography to characterize trapped guest or aggregates inside them, if suffici...

A self-cleaning coating based on TiO2 nanoparticles obtained by sol–gel method in an alkaline environment has been tested on different types of carbonatic stones: Botticino, Carrara and Pietra Dorata, frequently used in historic buildings. XRD and Raman measurements confirmed the nanocrystalline nature of titania in anatase form, with 5–10 nm cryst...

A novel treatment based on polyamidoamines (PAAs) for the preservation of wood against fungi and insects with a broad protection functionality, low effective concentration, and low environmental impact has been developed. PAAs were synthesized by nucleophile addition of ethanolamine (EtA) and/or 3-aminopropyltriethoxysilane (APTES) to N,N′-methylen...

The study focuses on the π-π stacking geometry exhibited in the solid state by 3,7-bis(dimethylamino)phenothiazin-5-ium, also known as methylene blue cation (MBC) associated with different counter-anions, in particular metallate ions. The preparations of all the compounds were carried out in the solid state, by grinding MBC chloride together with...

The study deals with the syntheses and the structural characterization of complexes formed by 3,7-bis(dimethylamino)-phenothiazin-5-ium, also known as methylene blue cation (MBC) and chlorometallates of the type [MCl2]- (M = Cu, Ag, Au). All the compounds have been prepared in the solid state, by manual grinding of the reagents. The resulting powd...

The study deals with the syntheses and the structural characterizations of complexes formed by methylene blue cation (MBC) and various chlorometallates, in particular of copper, gold, silver and mercury. The preparations of all the compounds have been carried out in the solid state, via grinding reactions between the starting reagent salts. The re...

The crystal structure of N,N′-methylenebisacrylamide was determined through the geometry optimization of the molecular unit with density functional theory and conformational analysis, and then through the calculation of the packing via a crystal structure prediction protocol, based on lattice energy minimization. All the calculated structures were...

Self-cleaning photocatalytic coatings based on TiO2 nanoparticles obtained by sol–gel techniques at two different pH values (1.3–10.6) have been investigated on carbonatic stone. The selected material is the yellowish lithofacies of Palazzolo Formation calcarenite, commonly named Pietra di Noto, widely used in the Baroque monuments of the Noto Vall...

MCM-41-supported molybdenum/bis-dithiocarbamate complex can be efficiently utilized, after treatment with tert-butylhydroperoxide (TBHP), for the epoxidation of alkenes under solventless conditions. The treatment with TBHP allows the formation of the real catalyst through oxidative decomposition of the complex affording well dispersed Mo(VI) specie...

Three crystal structures of Ni compounds containing bis(pyridine-2-carbaldehyde thiosemicarbazone) ligand (HL), namely (pyridine-2-carbaldehyde thiosemicarbazonato)(pyridine-2-carbaldeyde thiosemicarbazone) nickel(II) nitrate hydrate [Ni(HL)L][NO3]center dot(H2O) (1), bis(pyridine-2-carbaldehyde thiosemicarbazone) nickel(II) dinitrate [Ni(HL)(2)][N...

The sol–gel synthesis of water-based sols of nanocrystalline TiO2 in a large pH range (1.3–10.6) was carried out by acid hydrolysis of titanium(IV) isopropoxide with acetic acid or malonic acid acting also as complexing agents. Subsequent peptization was achieved in acid medium, in the case of acetic acid, and in basic medium (through triethylamine...

Self-cleaning photocatalytic coatings for biocalcarenite stones, based on TiO2 nanoparticles obtained by sol-gel processes at different pH values and also adding gold particles, have been investigated. The selected test material is a biocalcarenite named "pietra di Lecce" (Lecce stone), outcropping in Southern Italy. Scanning electron microscopy wi...

The 68-electrons, phosphane-substituted, osmium selenido-carbonyl cluster [Os4Se3(CO)10(dppm)] (cluster 3; dppm = bis(diphenylphosphino)methane) has been obtained by reaction under mild experimental conditions between [Os3(CO)12] and the diphosphane diselenide dppmSe2. Its crystal and molecular structure has been elucidated by X-ray diffraction met...

Previous preliminary studies showed good efficacy of treatments based on a mixture of siloxane materials, functionalized with amino groups and coupled with copper, against the brown rot fungus Coniophora puteana (Palanti et al. 2011). In the present work, a one-step impregnation was performed on two sets of samples differing in size, in order to ve...

In this work, sol–gel derived silica films were prepared for direct desorption/ionization of organic compounds in MALDI-TOF–MS analysis with the aim of improving method precision and of reducing interfering signals at low m/z values. Two commonly used MALDI matrices, 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (CHCA), were in...

Interpenetration of wood samples of pine sapwood (Pinus sylvestris L.) with hybrid inorganic–organic silica xerogels bearing amine functions able to coordinate copper(II) cations has been successfully carried out. These materials have been prepared by sol–gel processing TEOS/APTES mixtures inside the wood. Solid state 29Si NMR data provide evidence...

Wood modification with siloxanes bearing amino groups with copper-linking function was carried out by a sol–gel process. Tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) were the main components. Two different procedures were followed: a two-step process (impregnation with the TEOS/APTES mixture followed by dipping into a copper su...

The structure of the title compound, [Ph3P=N=PPh3]⁺[Ph3SnCl2]⁻ or (C36H30NP2)[Sn(C6H5)3Cl2], obtained as a by product of the reaction between Ph3SnCl and [Ph3P=N=PPh3]⁺·HSeO3⁻, consists of discrete essentially isolated ions. Both the cation and the anion lie on twofold axes which pass through the central N atom in the cation and through the SnIV at...

Wood manufactured products are subjected to biological decay due to fungi and insects. The use of copper chelates as biocides was proposed, due to their high stability which minimizes copper leaching into the environment. Considering the remarkable effectiveness showed by copper chelates on brown rot fungi, zinc and copper salicylate complexes were...

The reaction of Ni(NO3)(2)center dot 6H(2)O with Na2SeO3 in the presence of tetramethylethylenediamine (TMEDA) in a water/ethanol mixture yielded the heteroleptic complex [{Ni(TMEDA)SeO3}(2)] (1). Single-crystal X-ray diffraction analysis showed that complex 1 consists of a dinuclear species in which the two nickel atoms are held together by two br...

Sol-gel-based materials were synthesized, characterized and finally tested as solid supports for desorption electrospray ionization-mass spectrometry (DESI-MS) analysis of a mixture of compounds of different polarity. Films with thickness in the 2-4 μm range were obtained by a dip-coating process using tetraethoxysilane (TEOS) and octyltriethoxysil...

Silica-copper molybdates prepared by sol-gel and impregnation methods were tested as catalysts in the oxidation of propene at 400 °C, both in a pulse and in a flow reactor. Their catalytic activity is connected to their structural features, as revealed by electron paramagnetic resonance (EPR) and X-ray diffraction (XRD) characterization.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An anionic Pd₁₅-oxo-cluster [Pd₁₅(μ₃-SeO₃)₁₀(μ₃-O)₁₀Na]⁹⁻ has been synthesized. It is the result of an unprecedented self-assembly of Pd(2+) and Na(+) cations, SeO₃²⁻ and oxo anions. It has been found for the first time, that selenito groups can give rise to supramolecular interactions in the solid state with palladium atoms, through the selenium e...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The title complex has been synthesized by refluxing a toluene solution of Co2(CO)8 and the diyne [(HCCCMe2)2NMe]. It has been characterized by IR and NMR spectroscopy and its structure determined by an X-ray diffraction study. The complex is one of the few examples of a crystallographically characterized cobaltacyclopentadiene derivative. It can b...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The reaction of trialkylphoshanes and amino-phosphanes with isothiocyanates yields adducts containing the zwitterionic thioamidyl-phosphonium P+C(S)N- functional group. Ligands containing this group were not previously Studied, probably due to their instability towards dissociation, in the presence of metal species able to coordinate the P atom. Th...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

2′-Hydroxyphenylpyridinemethanols 7 were synthesized by metal-template ortho-regioselective alkylation of phenols 5 with 2-, 3- and 4-pyridinealdehydes 6.

The aim of this research was to realize new potential wood preservatives against fungal decay, with low environmental impact and well fixed into the wood. Pinus sylvestris L. wood samples were impregnated by silica xerogels functionalized with amino groups able to link copper through coordinative interactions. In this study tetraethoxysilane (TEOS)...

Two bread wheat (Triticum aestivum L.) cultivars (Albimonte, traditional cultivar very important in Italy since long time; and Manital, more recent, evincing better productive performances) were grown for 10 d in presence of 0.7 (control), 70 or 350 μM ZnSO4, to verify whether Zn excess was differently managed at inter-varietal and at inter-organ l...

The bis-chelate complex of Zn2+ with 2-hydroxy-(4-methylthio)butanoate (MHA-H the anion derived from the so-called methionine hydroxy-analogue, MHA) is an effective, bioavailable mineral supplement for animal feeding. It can be obtained in two solid forms: the anhydrous [Zn(OC(O)CH2CH(OH)CH2CH2SCH3)2] and the corresponding dihydrate species, both w...

The reaction of EtNHC(S)Ph2P[double bond, length as m-dash]NP+Ph2C(S)N(-)Et (HEtSNS) with [Ru3(CO)12] has been carried out under two different experimental conditions: in the first case [Ru3(CO)12], previously turned into the labile intermediate [Ru3(CO)10(CH3CN)2], afforded, at room temperature in dichloromethane, the trinuclear clusters [Ru3(CO)1...

Wood modification by sol-gel treatments shows many positive features, like antimicrobial properties. Wood was also successfully modified with alkoxysilanes enhancing its resistance against soil micro-organisms. Silver, copper, zinc compounds, boric acid or organic biocides such as alkylammonium compounds may be added to the sol-gel to enhance its b...

Heparin is an anticoagulant which is widely used during blood-dialysis. To now, there is not a commercial device able to “filter” heparin from blood after or during the medical treatment. Heparin can give, on life-long treatments, several health problems. We prepared siloxane-modified hybrid poly(aminoamides) which can be obtained from water soluti...

A green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with stoichiometric amount of 30% aq. H2O2 is reported. The reaction is performed in methanol with silica-vanadia as heterogeneous and reusable catalyst.

IntroductionClusters derived from Ph3PSeCluster derived from (Ph2PSe)2XStructural featuresCluster growth reactionsConcluding remarks

At present the main products against wood decay are copper salts with other "co-formulating" substances such as boron, azoles and organic compounds. The role of these compounds is to increase the protective effect and the fixation of the copper derivatives to the wood, aiming at reducing their dispersion in the environment. Some copper-based preser...

The speciation study of the Zn(2+)/glutathione (GSH, H(3)G) and Zn(2+)/N-acetylcysteinylglycine (NAcCG, H(2)L) was performed in aqueous solution by means of potentiometry and ESI mass spectrometry. The ligand N-acetylcysteinylglycine was synthesized by protection/activation strategies. (1)H NMR data for the Zn(2+)/NAcCG system at different pH were...

In the clusters [Ru3(micro(3)-NPPh(3))(micro(3)-OSiMe(3))(micro-X)(micro(C,O)-OC[double bond]NPPh(3))(micro-CO)(CO)6] (X = NCO, 2; X = Cl, 3), which were prepared by a pyrolytic reaction of Ph(3)PNSiMe(3) with Ru(3)(CO)12, the ligands result from a cluster-mediated pseudo-Hofmann rearrangement involving the micro-NCO, micro(C,O)-Ph(3)P[double bond]...

Mineral chelates (or metal chelates) in nutrition, i.e. the so-called organic trace minerals, represent the most outstanding proposal of mineral supplementation currently available on the market. They arc formed by a transition metal ion (such as Zn2+, Cu2+) and one or more organic chelating molecules (ligands). It is now generally accepted that me...

The species Ru3(H)(mu3-NPPh3)(CO)9 occurs in the solid state as two isomers, characterized either by one capping hydride and three CO bridges (1a) or by one bridging hydride and all terminals COs (1b); key intermediates for the formation, fluxionality and solvent-dependent interconversion of the isomers are highlighted through a DFT MO analysis.

The reaction of Ph(2)PNHPPh(2) (PNP) with RNCS (Et, Ph, p-NO(2)(C(6)H(4))) gives addition products resulting from the attack of the P atoms of PNP on the electrophilic carbon atom of the isothiocyanate. When PNP is reacted with EtNCS in a 1:2 molar ratio, the zwitterionic molecule EtNHC(S)PPh(2)==NP(+)Ph(2)C(S)N(-)Et (HSNS) is obtained in high yiel...

The alpha-hydroxyacid 2-hydroxy-4-methylthiobutanoic acid (the so-called methionine hydroxy-analogue, MHA), largely used in animal nutrition as a source of methionine, forms stable metal chelates with divalent metals of formula [{CH(3)SCH(2) CH(2)CH(OH)COO}(2)M].nH(2)O. Protonation and iron(III) and copper(II) complex formation constants have been...