Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

Endophytic fungi harbored in Cannabis sativa L.:diversity and potential as biocontrol agents against host plant-specific phytopathogens

The objective of the present work was isolation,phylogenetic characterization,and assessment of biocontrol potential of endophytic fungi harbored in various tissues(leaves,twigs,and apical and lateral buds)of the medicinal plant,Cannabis sativa L.A total of 30 different fungal endophytes were isolated from all the plant tissues which were authenticated by molecular identification based on rDNA ITS sequence analysis(ITS1,5.8S and ITS2 regions).The Menhinick’s index revealed that the buds were immensely rich in fungal species,and Camargo’s index showed the highest tissue-specific fungal dominance for the twigs.The most dominant species was Penicillium copticola that could be isolated from the twigs,leaves,and apical and lateral buds.A detailed calculation of Fisher’s log series index,Shannon diversity index,Simpson’s index,Simpson’s diversity index,and Margalef’s richness revealed moderate overall biodiversity of C.sativa endophytes distributed among its tissues.The fungal endophytes were challenged by two host phytopathogens,Botrytis cinerea and Trichothecium roseum,devising a dual culture antagonistic assay on five different media.We observed 11 distinct types of pathogen inhibition encompassing a variable degree of antagonism(%)on changing the media.This revealed the potential chemodiversity of the isolated fungal endophytes not only as promising resources of biocontrol agents against the known and emerging phytopathogens of Cannabis plants,but also as sustainable resources of biologically active and defensive secondary metabolites.

Vinylene-Linked Two-Dimensional Covalent Organic Frameworks:Synthesis and Functions

Two-dimensional covalent organic frameworks(2D COFs)with covalently bonded repeat units and crystalline,porous framework backbones have attracted immense attention since the first 2D COFs were reported by Yaghi’s group in 2005.The extended single-layer structures of 2D COFs are also generally considered to be the 2D polymers.The precise incorporation of molecular building blocks into ordered frameworks enables the synthesis of novel organic materials with designable and predictable properties for specific applications,such as in optoelectronics,energy storage,and conversion.In particular,the 2Dπ-conjugated COFs(2D-c-COFs)represent a unique class of 2D conjugated polymers that have 2D molecular-periodic structures with extended in-planeπ-conjugations.In the 2D-c-COFs,the conjugated skeletons andπ−πstacking interactions can provide the pathways for electron transport,while the porous channel can enable the loading of active sites for catalysis and sensing.Thus far,the synthesis of 2D-c-COFs has been mostly limited to Schiff base chemistry based on the condensation reaction between amine and aldehyde/ketone monomers because the construction of 2D COFs as thermodynamically controlled products generally requires a highly reversible reaction for error-correction processes.However,the high reversibility of imine linkages would conversely endow moderateπ-electron delocalization due to the polarized carbon−nitrogen bonds and poor stability against strong acids/bases.To achieve robust and highly conjugated 2D-c-COFs,a series of synthesis strategies have been developed,including a one-step reversible reaction with a bond-forming−bond braking−bond reforming function,a quasi-reversible reaction combing reversible and irreversible processes,and postmodifications converting labile bonds to a robust linkage.Among all of the reported 2D-c-COFs,vinylene-linked(also sp^(2)-carbon-linked)2D covalent organic frameworks(V-2D-COFs)with high in-planeπ-conjugation have attracted increasing interest after we reported the first V-2D-COFs via a Knoevenagel polycondensation in 2016.Although CC bonds have low reversibility,making the synthesis of V-2D-COFs quite challenging,there have been around 40 V-2D-COFs reported over the past 5 years,which demonstrated the merits of V-2D-COFs combining with unique optoelectronic,redox,and magnetic properties.In this Account,we will summarize the development of V-2D-COFs,covering the important aspects of synthesis methods,design strategies,unique physical properties,and functions.First,the solvothermal synthesis of V-2D-COFs using different reaction methodologies and design principles will be presented,including Knoevenagel polycondensation,other aldol-type polycondensations,and Horner−Wadsworth−Emmons(HWE)polycondensation.Second,we will discuss the optoelectronic and magnetic properties of V-2D-COFs.Finally,the promising applications of V-2D-COF in the fields of sensing,photocatalysis,energy storage,and conversion will be demonstrated,which benefit from their robust vinylene-linked skeleton,full in-planeπ-conjugation,and tailorable structures.We anticipate that this Account will provide an intensive understanding of the synthesis of V-2D-COFs and inspire the further development of this emerging class of conjugated organic crystalline materials with unique physicochemical properties and applications across different areas.