Perspective Chapter: Functional Sol–Gel Based Coatings for Innovative and Sustainable Applications

Alkoxysilanes represent a class of molecules widely employed to achieve the preparation of plenty of functional surfaces by easy, cost-effective and eco-friendly sol–gel methods. In this regard, the advancements of research activities include the proper design of film/patterns/brushes, by starting from opportune alkoxysilane and/or other metal/metalloid precursors, in order to obtain efficient innovative and homogenous functional surfaces showing implemented properties by means of the simple and eco-friendly sol–gel method. Therefore, in light of these aspects, the employment of opportune functional alkoxysilanes, either in combination with other nanofillers or molecules, is a key step for the design, and development of sol–gel based nanohybrid or nanocomposite coatings suitable for different surface properties implementation and applications, spanning from blue-growth sector to smart and technical textiles, from biomedicine to building and cultural heritages, from environmental remediation to catalysis. Some of the most relevant and explicative examples of these innovative and sustainable sol–gel based coatings will be described in this chapter

Gold Derivatives Development as Prospective Anticancer Drugs for Breast Cancer Treatment

Commonly used anticancer drugs are cisplatin and other platinum‐based drugs. However, the use of these drugs in chemotherapy causes numerous side effects and the onset of frequent drug resistance phenomena. This review summarizes the most recent results on the gold derivatives used for their significant inhibitory effects on the in vitro proliferation of breast cancer cell models and for the consequences deriving from morphological changes in the same cells. In particular, the study discusses the antitumor activity of gold nanoparticles, gold (I) and (III) compounds, gold complexes and carbene‐based gold complexes, compared with cisplatin. The results of screening studies of cytotoxicity and antitumor activity for the gold derivatives show that the death of cancer cells can occur intrinsically by apoptosis. Recent research has shown that gold (III) compounds with square planar geometries, such as that of cisplatin, can intercalate the DNA and provide novel anticancer agents. The gold derivatives described can make an important contribution to expanding the knowledge of medicinal bioorganometallic chemistry and broadening the range of anticancer agents available, offering improved characteristics, such as increased activity and/or selectivity, and paving the way for further discoveries and applications

N-thioalkylcarbazoles derivatives as new antiproliferative agents: synthesis, characterisation and molecular mechanism evaluation

Synthetic or natural carbazole derivatives constitute an interesting class of heterocycles, which showed several pharmaceutical properties and occupied a promising place as antitumour tools in preclinical studies. They target several cellular key-points, e.g. DNA and Topoisomerases I and II. The most studied representative, i.e. Ellipticine, was introduced in the treatment of metastatic breast cancer. However, because of the onset of dramatic side effects, its use was almost dismissed. Many efforts were made in order to design and synthesise new carbazole derivatives with good activity and reduced side effects. The major goal of the present study was to synthesise a series of new N-thioalkylcarbazole derivatives with anti-proliferative effects. Two compounds, 5a and 5c, possess an interesting anti-proliferative activity against breast and uterine cancer cell lines without affecting non-tumoural cell lines viability. The most active compound (5c) induces cancer cells death triggering the intrinsic apoptotic pathway by inhibition of Topoisomerase II

Development of Functional Hybrid Polymers and Gel Materials for Sustainable Membrane-Based Water Treatment Technology: How to Combine Greener and Cleaner Approaches

Water quality and disposability are among the main challenges that governments and societies will outside during the next years due to their close relationship to population growth and urbanization and their direct influence on the environment and socio-economic development. Potable water suitable for human consumption is a key resource that, unfortunately, is strongly limited by anthropogenic pollution and climate change. In this regard, new groups of compounds, referred to as emerging contaminants, represent a risk to human health and living species; they have already been identified in water bodies as a result of increased industrialization. Pesticides, cosmetics, personal care products, pharmaceuticals, organic dyes, and other man-made chemicals indispensable for modern society are among the emerging pollutants of difficult remediation by traditional methods of wastewater treatment. However, the majority of the currently used waste management and remediation techniques require significant amounts of energy and chemicals, which can themselves be sources of secondary pollution. Therefore, this review reported newly advanced, efficient, and sustainable techniques and approaches for water purification. In particular, new advancements in sustainable membrane-based filtration technologies are discussed, together with their modification through a rational safe-by-design to modulate their hydrophilicity, porosity, surface characteristics, and adsorption performances. Thus, their preparation by the use of biopolymer-based gels is described, as well as their blending with functional cross-linkers or nanofillers or by advanced and innovative approaches, such as electrospinning

Protonolysis of Dialkyl and Alkylaryl Platinum(II) Complexes and Geometrical Isomerization of the Derived Monoorgano-Solvento Complexes: Clear-Cut Examples of Associative and Dissociative Pathways in Platinum Chemistry

SynopsisProtonolysis of the title compounds involves rate-determining proton transfer to the substrate. Subsequent isomerization is dissociative. Activation volumes for the two processes have opposite signs. A new kinetic β-hydrogen accelerating effect for isomerization favoring the fluxionality of a T-shaped 14-electron intermediate is reported.AbstractProtonolysis of the complexes cis-[PtR2(PEt3)2] (R = Me, Et, Prn, Bun, CH2C(Me)3, CH2Si(Me)3) and cis-[Pt(R)(R‘)(PEt3)2] (R = Ph, 2-MeC6H4, 2,4,6-Me3C6H2; R‘ = Me) in methanol selectively cleaves one alkyl group, yielding cis-[Pt(R)(PEt3)2(MeOH)]+ and alkanes. The reactions occur as single-stage conversions from the substrate to the product. There is no evidence by UV and by low-temperature 1H and 31P NMR spectroscopy for the presence of significant amounts of Pt(II) or Pt(IV) intermediate species. Reactions are first order with respect to complex and proton concentrations and are strongly retarded by steric congestion at the Pt−C bond, varying from k2 = (2.65 ± 0.08) × 105 M-1 s-1 for R = R‘ = Et to k2 = 9.80 ± 0.44 M-1s-1 for R = R‘= CH2Si(Me)3. Low enthalpies of activation and largely negative volumes of activation are associated with the process. The mechanism involves a rate-determining proton transfer either to the metal−carbon σ bond (SE2 mechanism) or to the metal center (SE(oxidative) mechanism), followed by fast extrusion of the alkane and simultaneous blocking of the vacant coordination site by the solvent to generate cis-[Pt(R)(PEt3)2(MeOH)]+ species. The subsequent slower process, cis to trans isomerization of cis-[Pt(R)(PEt3)2(MeOH)]+, is characterized by high values of enthalpies of activation, positive entropies of activation, and largely positive volumes of activation. The reaction is shown to proceed through the dissociative loss of the weakly bonded molecule of solvent and the interconversion of two geometrically distinct T-shaped 14-electron 3-coordinate intermediates. The presence of β-hydrogens on the residual alkyl chain produces a great acceleration of the rate (R = Me, ki = 0.0026 s-1; R = Et, ki = 44.9 s-1) as a consequence of the stabilization of the 3-coordinate [Pt(R)(PEt3)2]+ transition state through an incipient agostic interaction. The results of this work, together with those of a previous paper, give a rationale of the “elusive” nature of these compounds. The following factors concur: (i) electron release by the phosphine ligands, (ii) steric repulsion and distortion of the square-planar configuration, and (iii) interaction of the metal with β-hydrogens

Geopolymers and Functionalization Strategies for the Development of Sustainable Materials in Construction Industry and Cultural Heritage Applications: A Review

In the last decades, new synthetic hybrid materials, with an inorganic and organic nature, have been developed to promote their application as protective coatings and/or structural consolidants for several substrates in the construction industry and cultural heritage field. In this context, the scientific community paid attention to geopolymers and their new hybrid functional derivatives to design and develop innovative and sustainable composites with better chemical resistance, durability and mechanical characteristics. This review offers an overview of the latest progress in geopolymer-based hybrid nanofunctional materials and their use to treat and restore cultural heritage, as well as their employment in the building and architectural engineering field. In addition, it discusses the influence of some parameters, such as the chemical and physical characteristics of the substrates, the dosage of the alkaline activator, and the curing treatment, which affect their synthesis and performance

1,1′-Bis(diphenylphosphino)ferrocene Platinum(II) Complexes as a Route to Functionalized Multiporphyrin Systems

In this study, the cationic complex [PtMe(Me2SO)(dppf)]CF3SO3 (PtFc) (dppf = 1,1′-bis(diphenylphosphino)ferrocene) was exploited as a precursor to functionalize the multi-chromophoric system hexakis(pyridyl-porphyrinato)benzene (1). The final adduct [PtFc]18-1, containing eighteen platinum(II) organometallic [PtMe(dppf)] fragments, was prepared and characterized through UV/Vis absorption, 31P{1H}-NMR spectroscopy, and fluorescence emission. UV/vis and fluorescence titrations confirmed the coordination between the platinum(II) center and all the pyridyl moieties of the peripheral substituent groups of the porphyrin. The drop casting of diluted dichloromethane solution of [PtFc]18-1 onto a glass surface afford micrometer-sized emissive porphyrin rings

Multifunctional Dyeing of Wool Fabrics Using Selenium Nanoparticles

This work aims to utilize selenium nanoparticles (Se-NPs) as a novel dyestuff, which endows wool fibers with an orange color because of their localized surface plasmon resonance. The color characteristics of dyed fibers were evaluated and analyzed. The color depth of the dyed fabrics under study was increased with the increase in Se content and dyeing temperature. The colored wool fabrics were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and an X-ray diffraction (XRD) analysis. The results indicated that spherical Se-NPs with a spherical shape were consistently deposited onto the surface of wool fibers with good distribution. In addition, the influence of high temperature on the color characteristics and imparted functionalities of the dyed fabrics were also investigated. The obtained results showed that the proposed dyeing process is highly durable to washing after 10 cycles of washes, and the acquired functionalities, mainly antimicrobial activity and UV-blocking properties, were only marginally affected, maintaining an excellent fastness property

Overcrowded organometallic platinum(II) complexes that behave as molecular gears

In gear: Dynamic 1H NMR studies on some organometallic platinum(II) compounds reveal a synchronism between rotation around the Pt-P bond and the oscillation of a phenanthroline ligand between two nonequivalent exchanging sites. The system behaves as a molecular-sized analogue of a mechanical gear (see picture; C gray, N blue, O red, P purple) whose dynamic properties can be tuned through small structural changes. (Figure Presented