One step forward towards the development of eco-friendly antifouling coatings: Immobilization of a sulfated marine-inspired compound

Marine biofouling represents a global economic and ecological challenge and few eco-friendly antifouling agents are available. The aim of this work was to establish the proof of concept that a recently synthesized nature-inspired compound (gallic acid persulfate, GAP) can act as an eco-friendly and effective antifoulant when immobilized in coatings through a non-release strategy, promoting a long-lasting antifouling effect. The synthesis of GAP was optimized to provide quantitative yields. GAP water solubility was assessed, showing values higher than 1000 mg/mL. GAP was found to be stable in sterilized natural seawater with a half-life (DT50) of 7 months. GAP was immobilized into several commercial coatings, exhibiting high compatibility with different polymeric matrices. Leaching assays of polydimethylsiloxane and polyurethane-based marine coatings containing GAP confirmed that the chemical immobilization of GAP was successful, since releases up to fivefold lower than the conventional releasing systems of polyurethane-based marine coatings were observed. Furthermore, coatings containing immobilized GAP exhibited the most auspicious anti-settlement effect against Mytilus galloprovincialis larvae for the maximum exposure period (40 h) in laboratory trials. Overall, GAP promises to be an agent capable of improving the antifouling activity of several commercial marine coatings with desirable environmental properties.This research was funded by national funds through the Foundation for Science and Technology (FCT) within the scope of research unit grants to CIIMAR (UIDB/04423/2020 and UIDP/04423/2020), to BioISI (UIDB/04046/2020 and UIDP/04046/2020) and under the project PTDC/AAG-TEC/0739/2014 (reference POCI-01-0145-FEDER-016793) supported through national funds provided by FCT and the European Regional Development Fund (ERDF) via the Programa Operacional Factores de Competitividade (POFC/COMPETE) programme and the Reforçar a Investigação, o Desenvolvimento Tecnológico e a Inovação (RIDTI; project 9471)

Molecular Orbital Calculations On Model Fe(co)2l(η4-enone) Complexes With L = Co, Ph3, And P(oh)3. Electronic And Steric Effects In Fe(co)2l(η4-benzylideneacetone)

The bonding properties of the model complexes Fe(CO)2L(η4-butadiene) and Fe(CO)2L(η4-enone) with L = CO, PH3, and P(OH)3 were studied. The characteristics of the frontier orbitals of the Fe(CO)2L fragments determine their interaction with the butadiene and enone ligands completing the metal coordination sphere. The frontier orbitals of butadiene are stabilized when one CH2 is replaced by the more electronegative oxygen atom. The staggered conformation is preferred by the Fe(CO)3(η4-enone) complexes. The most stable of the three possible staggered conformations of Fe(CO)2L(η4-enone) is the one in which the phosphorus ligand is approximately trans to the central C-C bond of the enone. The strongest interaction between the enone and Fe(CO)2L is back-donation from the HOMO of the metal fragment to the empty π3 orbital of the enone, more electrons thus being donated than received by the metal. Electron density is mainly lost by the oxygen atom and gained by the terminal carbon atom (C4) of the enone. The results were used to interpret the isomer distribution in Fe(CO)2L(η4-enone) and the electronic effects in Fe(CO)2L(η4-benzylideneacetone) complexes where L is CO, phosphine, and phosphite. © 1990 American Chemical Society.941060106

Insertion of isonitrile into the Mo-C bond of [MoCp2(CH3)(CNH)]+: a density functional

The reaction of CNH with the methyl group in the transition metal complex [MoC

Ag(I) and Cu(I) complexes of tetramethyldiphosphinedisulfide: synthesis and structure

Reaction of [M(NCCH3)(4)][PF6] (M = Ag, Cu) with the S2P2Me4 ligand in dichloromethane solution led to substitution of all the nitrile ligands by two molecules of the sulfur ligand, affording the new species [Ag(S2P2Me4)(2)][PF6] (1) and [Cu(S2P2Me4)(2)][PF6] (2). The structures of these complexes were determined by single crystal X-ray diffraction. showing the expected tetrahedral coordination around each metal. Density functional theory (DFT) calculations confirmed the different geometries and energies of the free and coordinated ligand, and provided a very good reproduction of the experimental structures, both for Ag and Cu. The lengths of the S=P bonds are barely affected by coordination, indicating that the pi bond is not important in binding to the metal. (C) 2002 Elsevier Science B.V. All rights reserved