Bis(triphenyl­phosphanyl­idene)iminium dichloridotriphenyl­stannate(IV)

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 atom in the anion. In the crystal, the ions inter­act only through a weak inter­action between the Cl atom of the anion and an H atom of a phenyl ring of the cation

Hydroalkoxylation of Terminal and Internal Alkynes Catalyzed by Dinuclear Gold(I) Complexes with Bridging Di(N-Heterocyclic Carbene) Ligands

A series of six dinuclear gold(I) complexes with bridging bidentate N-heterocycic carbene ligands (NHCs) of general formula Au2Br2LX (L = diNHC, X = 1\u20136) have been studied as catalysts in the intermolecular hydroalkoxylation of terminal and internal alkynes. The best catalytic results have been obtained by using Au2Br2L4, characterized by 2,6-diisopropylphenyl wingtip substituents and a methylene bridging group between the two NHC donors. Complex Au2Br2L4 has been structurally characterized for the first time in this work, showing the presence of intramolecular aurophiclic interaction in the solid state. In the adopted reaction conditions Au2Br2L4 is able to convert challenging substrates such as diphenylacetylene. Comparative catalytic tests by using the mononuclear gold(I) complexes AuIL7 and IPrAuCl have been performed in order to determine the possible presence of cooperative effects in the catalytic process

Three-Dimensional (3D) Printed Silver Nanoparticles/Alginate/Nanocrystalline Cellulose Hydrogels: Study of the Antimicrobial and Cytotoxicity Efficacy

Here, a formulation of silver nanoparticles (AgNPs) and two natural polymers such as alginate (ALG) and nanocrystalline cellulose (CNC) was developed for the 3D printing of scaffolds with large surface area, improved mechanical resistance and sustained capabilities to promote antimicrobial and cytotoxic effects. Mechanical resistance, water content, morphological characterization and silver distribution of the scaffolds were provided. As for applications, a comparable antimicrobial potency against S. aureus and P. aeruginosa was demonstrated by in vitro tests as function of the AgNP concentration in the scaffold (Minimal Inhibitory Concentration value: 10 mg/mL). By reusing the 3D system the antimicrobial efficacy was demonstrated over at least three applications. The cytotoxicity effects caused by administration of AgNPs to hepatocellular carcinoma (HepG2) cell culture through ALG and ALG/CNC scaffold were discussed as a function of time and dose. Finally, the liquid chromatography-mass spectrometry (LC-MS) technique was used for targeted analysis of pro-apoptotic initiation and executioner caspases, anti-apoptotic and proliferative proteins and the hepatocyte growth factor, and provided insights about molecular mechanisms involved in cell death induction

Neutral dinuclear gold(I) complexes with N-phosphanyl, N-heterocyclic carbenes (NHCPs)

Neutral dinuclear gold(I) complexes having general formula [Au2Cl2(NHCP)] (NHCP = N-phosphanyl N-heterocyclic carbene) have been synthesized by two different synthetic procedures: i) transmetalation of the NHCP ligand from the corresponding dinuclear silver(I) complex; ii) deprotonation of the corresponding N-phosphanyl azolium/tetrahydropyrimidinium salt in the presence of the gold(I) precursor. Interestingly, although the silver complexes are invariably dinuclear dicationic species of formula [Ag2(NHCP)2](OTf)2, both stoichiometries [Au2(NHCP)2](OTf)2 and [Au2Cl2(NHCP)] are potentially accessible with gold. Preference for either stoichiometry is dictated by the steric properties of the NHCP ligand as well as by a proper choice of the experimental conditions. On the other hand, preparation of copper(I) compounds with [Cu2Cl2(NHCP)] stoichiometry leads to product mixtures and has not led up to now to pure neutral compounds. Both the silver(I) and gold(I) complexes have been structurally characterized

Crystal Structures of Compounds Containing Ions Selenite

The chemistry of materials containing Se oxyanions in the +4 oxidation state, such as selenite, hydrogenselenite, and oxoselenate, are of increasing interest in the research community for several reasons. First, the lone pair on the selenium atom can behave as structure-directing agent towards the formation of materials characterized by the presence of hollows or channels in their intimate structures, moreover, the weakly coordinative capability of the Se(IV) electron lone pairs could give rise to interesting supramolecular interactions, and finally, it is known that the incorporation of selenite anions can lead to non-centrosymmetric structures and, consequently, to materials displaying remarkable physicochemical properties. The most important feature is that the full comprehension of the properties of this type of materials cannot be exhaustively understood unless the complete solid state crystal structure is available. In this Special Issue, entitled “Crystal Structures of Compounds Containing Ions Selenite”, a series of new selenite-containing compounds synthesized by different methodologies and fully caracterized in the solid state is reported. Moreover the fundamental role of detailed structural analysis in understanding the interactions in the solid state that are responsible for the peculiar chemical–physical properties of such materials is discussed

Role of Bis(triphenylphosphine)iminium Cation [PNP]+ on the Crystal Packing of [PNP]+[HSeO3]− Solvate Salt

Selenate(IV) and hydrogen selenate(IV) salts of bulky cations are very interesting compounds for synthetic and kinetic studies. In this work, bis(triphenylphosphine)iminium ([PNP]+) chloride has been used, which aims to synthesize the corresponding selenate(IV) salt by an exchange reaction in the aqueous solution and subsequent crystallization by solvent evaporation. Unexpectedly, the procedure afforded a solvate form of the [PNP]+[HSeO3]− salt (1). In this solid phase, which has a structure that is determined by Single Crystal XRD, the anion tends to maximize the interactions with itself, although it leaves the cationic moiety to have only weak interactions with the anions and the solvent molecules. In turn, the latter builds a network of effective hydrogen bonds. This behavior opposes the general tendency of selenite(IV) and hydrogen selenite(IV) compounds, since these anions are commonly found to have formed effective hydrogen bonds with surrounding chemical species. Moreover, as the exchange reaction is non-quantitative, the exceeding traces of the starting bis(triphenylphosphine)iminium chloride reagent reacted with bis(acetonitrile)dichloropalladium(II) to form the bis(triphenylphosphine)iminium hexachloropalladate (2). In the solid phase, [PNP]+ causes the absence of strong supramolecular interactions, which highlights the peculiar behavior of the cation in the crystal packing of its solid phases