Developing Carrier Complexes for “Caged NO”: RuCl3(NO)(H2O)2 Complexes of Dipyridylamine, (dpaH), N,N,N'N'-Tetrakis (2-Pyridyl) Adipamide, (tpada), and (2-Pyridylmethyl) Iminodiacetate, (pida2-)

Delivery agents which can carry the {Ru(NO)}6 chromophore (“caged NO”) are desired for vasodilation and for photodynamic therapy of tumors. Toward these goals, complexes derived from [RuCl3(NO)(H2O)2]= (1) have been prepared using dipyridylamine (dpaH) as mono and bis adducts, [Ru(NO)Cl3(dpaH)] = (2) and [Ru(NO)Cl(dpaH)2]Cl2 = (3). The dpaH ligands coordinate cis to the Ru(NO) axis.The mono derivative is a model for a potential DNA groove-spanning binuclear complex {[RuNO)Cl3]2(tpada)} = (4) which has two DNA-coordinating RuII centers, photo-labile {Ru(NO)}6 sites, and a groove-spanning tether moiety.The binuclear assembly is prepared from the tethered dipyridylamine ligand N,N,N',N'-tetrakis(2-pyridylmethyl)adipamide (tpada) which has recently been shown to provide a binuclear carrier complex suited to transporting RuII and PdII agents. A related complex, [Ru(NO)Cl(pida)] = (5) with the {Ru(NO)}6 moiety bound to (2-pyridylmethyl) iminodiacetate (pida2-) is also characterized as a potential “caged NO” carrier. Structural information concerning the placement of the pyridyl donor groups relative to the {Ru(NO)}6 unit has been obtained from 1H and 13C NMR and infrared methods, noting that a pyridyl donor trans to NO+ causes “trans strengthening” of this ligand for [Ru(NO)Cl(pida)], whereas placement of pyridyl groups cis to NO+ causes a weakening of the N-O bond and a lower NO stretching frequency in the dpa-based complexes

ФОРМИРОВАНИЕ ПРОЕКТИВНОГО ПОКРЫТИЯ ГАЗОННОГО ТРАВОСТОЯ ПРИ ПРИМЕНЕНИИ МИНЕРАЛЬНЫХ И КРЕМНИЙСОДЕРЖАЩИХ УДОБРЕНИЙ

Silicon containing fertilizer “Siliplant” and mineral fertilizers are established to influence ornamental traits of lawn herbage. Increased projective covering of lawn herbage – meadow grass and red fes-cue – is marked with the preparation “Siliplant” and mineral fertilizers applied, particularly with their joint application. In the first and second years of research in dry and excessively humid vegetation periods the optimal results were obtained through the joint treatment with mineral fertilizers and the preparation “Siliplant”: the projective covering increased in the year of sowing by averaged 27.5 % in meadow grass and 25 % in red fescue versus the control, in the second year the covering went up by averaged 19.7 and 8.44 %, respectively. Mineral fertilizers applied increased the projective covering in the year of sowing on average by 22.5 % in meadow grass and by 20 % in red fescue, in the second year they did by 14.7 % and 6.25 %, respectively. The treatment with the silicon-containing preparation “Siliplant” increased the projective covering in the year of sowing by averaged 15 % in meadow grass and by 7.5 % in red fescue; in the second vegetation period the averaged effect of the treatment was by 6.58 and 1.51 % higher, respectively.Установлено влияние кремнийсодержащего удобрения «Силиплант» и минеральных удобрений на декоративные качества газонного травостоя. Отмечено увеличение проективного покрытия газонных травостоев мятлика лугового и овсяницы красной при применении препарата «Силиплант» и минеральных удобрений, особенно при их совместном использовании. В  первый и второй годы исследований при засушливом и избыточно влажном вегетационном периоде оптимальные результаты получены при применении минеральных удобрений совместно с препаратом «Силиплант»: проективное покрытие увеличивалось в год посева в среднем на 27,5% у мятлика лугового и на 25% у овсяницы красной по отношению к контролю, во второй год – на 19,7 и 8,44% соответственно. Применение минеральных удобрений увеличивало проективное покрытие в год посева в среднем на 22,5% у мятлика лугового и на 20% у овсяницы красной, во второй год на 14,7 и 6,25% соответственно. Применение кремнийсодержащего препарата «Силиплант» увеличивало проективное покрытие в год посева в среднем на 15% у мятлика лугового и на 7,5% у овсяницы красной; во втором вегетационном периоде на 6,58 и на 1,51% соответственно

Biomimetic Synthesis of Nanoparticles

Biological systems provide numerous examples of highly controlled biomineralization processes that result in stabilized nanoparticles with superior optical properties, crystallinity, dispersity, and morphology. This is best exemplified by the selective mineralization of ferrihydrite (FeOOH·3H 2 O) as a labile source of iron within the iron storage protein ferritin. Consequently, these processes have inspired the use of biomolecular templates to mediate and mimic the synthesis of nano‐materials with a remarkable degree of success. Biomimetic approaches to nanoparticle synthesis include the use of single amino acids, small synthetic peptides (3–18 residues), phage displayed peptides, combinatorial libraries, native proteins, and plant viruses. In the following, we present these biologically inspired templates and methodologies; in addition to describing nanoparticle characterization, resultant properties, and implications for the nanoscale synthesis of materials

Peptide/Nanoparticle Biointerfaces for Multistep Tandem Catalysis

The realization of multifunctional nanoparticle systems is essential to achieve highly efficient catalytic materials for specific applications; however, their production remains quite challenging. They are typically achieved through the incorporation of multiple inorganic components; however, incorporation of functionality could also be achieved at the organic ligand layer. In this work, we demonstrate the generation of multifunctional nanoparticle catalysts using peptide-based ligands for tandem catalytic functionality. To this end, chimeric peptides were designed that incorporated a Au binding sequence and a catalytic sequence that can drive ester hydrolysis. Using this chimera, Au nanoparticles were prepared, which sufficiently presented the catalytic domain of the peptide to drive tandem catalytic processes occurring at the peptide ligand layer and the Au nanoparticle surface. This work represents unique pathways to achieve multifunctionality from nanoparticle systems tuned by both the inorganic and bio/organic components, which could be highly important for applications beyond catalysis, including theranostics, sensing, and energy technologies

Effect of a Mixed Peptide Ligand Layer on Au Nanoparticles for Optical Control of Catalysis

Inorganic colloidal nanoparticles are known for their efficient catalytic reactivities due to their enhanced surface-tovolume ratio. As an alternative to conventional synthetic methods, bioinspired approaches can sustainably generate stable colloidal nanoparticles where their reactivity can be tuned by the biomolecular overlayer structure. Recent studies have shown that incorporation of light-activated photoswitches into material-binding peptides could be used to optically and reversibly switch the biomolecular overlayer structure on Au nanoparticle surfaces, which has significant ramifications on the material catalytic reactivity. In this contribution, we demonstrate that the optical photoswitching capability and catalytic reactivity in these materials are highly dependent upon the composition of the biomolecular overlayer. For this, mixed monolayer-capped Au nanoparticles were prepared where the ratio of the parent material-binding peptide and the peptide with photoswitch included were varied. Key trends related to the photoswitching capability of the peptides and their overall reactivity were identified, where slower reactivity was noted for materials prepared using only the photoswitchable peptide. Taken together, these results demonstrate that the composition of the overlayer structure on Au nanoparticles is highly important in tuning the overall optical, photoswitching, and catalytic properties of these materials and can be used to refine the properties of the structure for their intended application

Substrate Effects on Remote Optical Control of Pt Nanoparticle-Driven Olefin Hydrogenation

Bioinspired approaches for materials synthesis and application are emerging as potentially sustainable approaches to achieve functional structures with selectively controlled properties (e.g., turn-on catalysis). An attractive avenue to allow for selective functionality is optical stimulation; however, the ability to make nanomaterials light responsive for many applications remains challenging. One approach is to incorporate photoswitches into the surface-adsorbed ligands which can stimulate a surface structural change that could have implications on the catalytic reactivity driven by the underlying metallic nanoparticle component. Herein we demonstrate the ability to drive optical switching of surface ligand overlayer structures on peptide-capped Pt nanoparticles. To this end, incorporation of an azobenzene unit into the surface-adsorbed peptide allows for the ability to optically reconfigure the ligand overlayer structure. This change results in direct manipulation of the catalytic properties of the Pt materials for olefin hydrogenation, which demonstrated changes in reactivity not only between different reagents but also between the different ligand structures. Such results present information that could be used in the design of ligand interface structures to trigger specific reactivity control for a variety of reactions and materials for sustainable catalysis

Peptide-Driven Fabrication of Catalytically Reactive Rhodium Nanoplates

Here we present the use of a well-known materials binding peptide for the generation of highly catalytically reactive Rh nanoplates. To this end, the A3 peptide, originally isolated with affinity for Ag, but with known abilities to bind Au, was used to generate Rh nanomaterials in solution. Rh was selected due to its established catalytic reactivity for numerous reactions; however, the preparation of materials of this composition typically requires high reaction temperatures and potentially caustic conditions. By use of the A3 peptide, Rh nanoplates can be generated in water, at room temperature, on the benchtop. The final structures were not spherical materials, which is typical for peptide-capped nanoparticles, but were plate-like in morphology. The materials were fully characterized and analyzed for olefin hydrogenation reactions. For this, the peptide-capped Rh nanoplates were highly reactive for alkene hydrogenation; however, the hydrogenation of alkynes was exceedingly slow and potentially blocked the surface to greatly inhibit reactivity. These results present a pathway toward the fundamental understanding of the structure/function relationship of peptide-capped nanocatalysts, which could be exploited for the future design of new materials with enhanced reactivity that are prepared under ambient conditions

Graphene exfoliation using multidomain peptides

Liquid-phase exfoliation using biomolecules in aqueous solution is a promising approach to obtain high quality 2D nanosheets. For example, the well-studied graphene-binding peptide, P1 (sequence HSSYWYAFNNKT), has been previously investigated and shown to have a good ability to exfoliate graphene sheets in aqueous conditions under sonication, maintaining colloidal stability. Building on this, the biomolecular exfoliant and assembly motif (BEAM) peptide, that features a graphene-binding domain at one end and a hexagonal boron nitride (h-BN) binding domain at the other, separated by a 10-carbon fatty acid chain in the centre, is shown to exfoliate graphene sheets from bulk graphite in aqueous media. An in-depth examination of the ability of the BEAM to both facilitate sheet exfoliation under sonication conditions and also maintain colliodal stability is provided through molecular dynamics simulations. These findings open new possibilities for designing multi-functional molecules that can both exfoliate and organise 2D materials into heterostructures under ambient conditions in aqueous media