Search

Xanthomonas axonopodis pv. glycines (Xag) is the causal agent of bacterial pustule disease and results in enormous losses in soybean production. Although isoflavones are known to be involved in soybean resistance against pathogen infection, the effects of exogenous isoflavones on soybean plants remain unexplored.Irrigation of soybean plants with isoflavone genistein inhibited plant growth for short periods, probably by inhibiting the tyrosine (brassinosteroids) kinase pathway, and increased disease resistance against Xag. The number of lesions was reduced by 59%-63% when applying 50 μg mlThe effects of exogenous genistein on soybean plants were examined for the first time, revealing new insights into the roles of isoflavones in soybean defense and demonstrating that irrigation with genistein can be a suitable method to induce disease resistance in soybean plants. © 2022 Society of Chemical Industry.

The role of solution aggregates on the charge transport process of conjugated polymers in electronic devices has gained increasing attention; however, the correlation of the charge carrier mobilities between the solution aggregates and the solid-state films remains elusive. Herein, three polymers, FBDOPV-2T, FBDOPV-2F2T, and FBDOPV-4F2T, are designed and synthesized with distinct aggregation behavior in solution. By combining contact-free ultrafast terahertz (THz) spectroscopy and field-effect transistor measurements, we track the charge carrier mobility of the aggregates of these polymers from the solution to the thin-film state. Remarkably, the mobility of these three polymers is found to follow nearly the same trend (FBDOPV-2T>FBDOPV-2F2T≫FBDOPV-4F2T) in both solutions and thin-film states. The quantitative mobility correlation indicates that the charge transport properties of solution aggregates play a critical role in determining the thin-film charge transport properties and final device performance. Our results highlight the importance of investigating and controlling solution aggregation structures towards efficient organic electronic devices.

Anisotropic magnetic exchange is of great value for the design of high performance molecular nanomagnets. In the present work, enhanced single-chain magnet (SCM) behavior is observed for a MoIII -MnII chain that exhibits anisotropic magnetic exchange. Self-assembly of the pentagonal bipyramidal [Mo(CN)7 ]4- anion and the MnII unit with a tridentate ligand results in a neutral double zigzag 2,4-ribbon structure which exhibits SCM behavior with a high relaxation barrier of 178(4) K. Open magnetic hysteresis loops are observed below 5.2 K, with a coercive field of 1.5 T at 2 K. Interestingly, this SCM can be considered to be a result of a step-wise process based on our previously reported Mn2 Mo single-molecule magnets (SMMs).

Strong interchain interactions of conjugated polymers usually result in poor miscibility with molecular dopants, limiting the doping efficiency because of uncontrolled phase separation. We have developed a strategy to achieve efficient charge-transport and high doping miscibility in n-doped conjugated polymers. We solve the miscibility issue through disorder side-chains containing dopants better. Systemic structural characterization reveals a farther side-chain branching point will lead to higher disorders, which provides appropriate sites to accommodate extrinsic molecular dopants without harming original chain packings and charge-transport channels. Therefore, better sustainability of solid-state microstructure is obtained, yielding a stable conductivity even when overloading massive dopants. This work highlights the importance of realizing high host-dopant miscibility in molecular doping of conjugated polymers.

Molecular ordering of conjugated polymers both in solution-state aggregates and in solid-state microstructures is a determining factor of the charge transport properties in optoelectronic devices. However, the effect of backbone conformation in conjugated polymers on assembly structures is still unclear. Herein, to understand such backbone conformation effect, three novel chlorinated benzodifurandionge-based oligo(p-phenylene vinylene) (BDOPV) polymers are systematically developed. These BDOPV-based polymers exhibit significantly twisted backbone conformation (near 90° interunit torsion angle) between conjugated units, which can prevent polymer chains from forming ordered assembly structures by increasing conformational energy penalty in closely packed chains. A higher rotational barrier of the torsion angle would further prevent polymer chains from assembling, finally resulting in nonaggregated chains in solution and highly disordered solid-state packing structures. This work will deepen the understanding of the relationship between polymer backbone conformation and assembly structures, contributing to the exploration of the structure-property relationship of polymers.

A bicomponent ion-pair molecule compound [Co(Brphterpy)₂][Co(NCS)₄]*2MeCN was designed and prepared for the construction of the functional materials of multi-stability. Due to the different coordination geometries of the cationic and anionic CoII ions, this compound exhibits both the thermally-induced spin crossover (SCO) and field-induced single-ion magnetism (SIM). This represents a rare example of a two-component system with the coexistence of SIM and SCO behaviors and suggests a simple, yet very efficient strategy for the construction of multi-stable molecular materials.

Relaxin-3 (also known as insulin-like peptide 7) is an insulin/relaxin-superfamily peptide hormone that can bind and activate three relaxin-family peptide receptors: RXFP3, RXFP4, and RXFP1. Recently, we identified key electrostatic interactions between relaxin-3 and its cognate receptor RXFP3 by using a charge-exchange mutagenesis approach. In the present study, the electrostatic interactions between relaxin-3 and RXFP4 were investigated with the same approach. Mutagenesis of the negatively charged extracellular residues of human RXFP4 identified a conserved EXXXD(100–104) motif that is essential for RXFP4 activation by relaxin-3. Mutagenesis of the conserved positively charged Arg residues of relaxin-3 demonstrated that B12Arg, B16Arg and B26Arg were all involved in the binding and activation of RXFP4, especially B26Arg. The activity complementation between the mutant ligands and the mutant receptors suggested two probable electrostatic interaction pairs: Glu100 of RXFP4 versus B26Arg of relaxin-3, and Asp104 of RXFP4 versus both B12Arg and B16Arg of relaxin-3. For interaction with the essential EXXXD motifs of both RXFP3 and RXFP4, a folding-back conformation of the relaxin-3 B-chain C-terminus seems to be critical, because it brings B26Arg sufficiently close to B12Arg and B16Arg. To test this hypothesis, we replaced the conserved B23Gly-B24Gly dipeptide of relaxin-3 with an Ala-Ser dipeptide that occupied the corresponding position of insulin-like peptide 5 and resulted in an extended helical conformation. The mutant relaxin-3 showed a significant decrease in receptor-activation potency towards both RXFP3 and RXFP4, suggesting that a folding-back conformation of the B-chain C-terminus was important for relaxin-3 to efficiently interact with the EXXXD motifs of both receptors. Structured digital abstract RXFP4 and relaxin-3 physically interact by competition binding (1, 2, 3, 4, 5, 6, 7, 8, 9)

Relaxin family peptides have important biological functions, and so far, four G-protein-coupled receptors have been identified as their receptors (RXFP1–4). A chimeric relaxin family peptide R3/I5, containing the B-chain of relaxin-3 and the A-chain of INSL5, is a selective agonist for both RXFP3 and RXFP4. In a previous study, europium-labeled R3/I5, as a nonradioactive and low-background receptor-binding tracer, was prepared through a chemical synthesis approach. In the present study, we established a convenient alternative approach for preparing the europium-labeled R3/I5 tracer based on a recombinant R3/I5 designed to carry a solubilizing tag at the A-chain N-terminus and a pyroglutamate residue at the B-chain N-terminus. Because of the presence of a single primary amine moiety, the recombinant R3/I5 peptide was site-specifically mono-labeled at the A-chain N-terminus by a diethylenetriaminepentaacetic acid/europium moiety through a convenient one-step procedure. The diethylenetriaminepentaacetic acid/Eu3+-labeled R3/I5 bound both receptors RXFP3 and RXFP4 with high binding affinities and low nonspecific binding. Thus, we have presented a valuable nonradioactive tracer for future interaction studies on RXFP3 and RXFP4 with various natural or designed ligands. The present approach could also be adapted for preparing and labeling of other chimeric relaxin family peptides. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

Relaxin-3 (also known as INSL7) is a recently identified neuropeptide belonging to the insulin/relaxin superfamily. It plays a putative role in the regulation of food intake, in the stress response and in reproduction by activating the G-protein-coupled receptor, RXFP3. In a previous study, we prepared 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)/Eu(3+)-labelled human relaxin-3 as a tracer for the study of ligand-receptor interactions, which necessitated a complicated site-specific labelling strategy because human relaxin-3 contains four primary amine moieties, all of which react with the primary amine-specific modification reagent. To simplify the labelling procedure, in the present study we created an easily labelled, recombinant analogue of human relaxin-3 with only one primary amine moiety at the A-chain N-terminus. The analogue retained full activity and could be easily labelled by various functional probes at the A-chain N-terminus. The DOTA/Eu(3+)-labelled analogue retained high binding affinity for its cognate receptor, RXFP3, and thus represents a useful, nonradioactive and stable tracer for studying the interaction of RXFP3 with various natural or synthetic ligands. This new analogue is also a suitable template for the design of other relaxin-3 analogues that can be easily labelled with the DOTA/Eu(3+) moiety and used to study binding activity and interactions with various RXFP3 analogues in the future.

Reaction of CoCl2·6H2O with equimolar bis(3,5-dimethylpyrazolyl)methane (dmpzm) produced a mononuclear adduct [Co(dmpzm)Cl2] (1). Treatment of 1 with sodium dicyanamide (dca) afforded a polymeric complex [Co(dmpzm)(μ-dca)2]∞ (2). 1 and 2 were characterized by elemental analysis, IR spectra, thermogravimetric analysis and single-crystal X-ray diffraction. The cobalt atom in 1 adopts a distorted tetrahedral coordination geometry, bound to two N atoms of one dmpzm and two Cl atoms. Complex 2 has a 2D brick-wall network (extended along the bc plane) in which the {[Co(dmpzm)(μ-dca)]2}2n+n chains are interconnected by pairs of μ-dca anions along the c axis. The magnetic properties of 1 and 2 were also investigated.

Low-dimensional magnetic compounds, especially zero-dimensional magnetic clusters and 1D chain compounds that show single-molecule and single-chain magnetic properties, are currently of ongoing interest for the design and synthesis of new molecule-based magnets. Well-documented examples include Mn12 [1] and Fe8 [2] for single-molecule magnets (SMMs), and [Co(hfacac)2(NITPhOMe)] (hfacac = hexafluoroacetylacetonate, NITPhOMe = 4′-methoxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and [Mn2(saltmen)2Ni(pao)2L2](A)2 (saltmen = N,N′-1,1,2,2-tetramethylethylenebis(salicylideneiminate), pao = pyridine-2-aldoximate, and A= anion) for single-chain magnets (SCMs). Although they are not associated with real 3D magnetic order, the slow magnetic relaxation and a hysteresis loop below the blocking temperature make them behave like classical magnets, and good candidates for potential high-density information storage. The slow relaxation phenomenon, which is one of the main characters for both SMMs and SCMs, is quite common for many systems, including magnetic systems, liquid crystals, polymers, high-critical-temperature (Tc) superconductors, and metallic glasses. Typical examples of magnetic systems, besides SMMs and SCMs, are spin-glass magnets, cluster spin-glass magnets, and classical superparamagnets. The origin of the relaxation is quite complex and varies in different systems. Randomness (defects, disorder, etc.) and frustration (geometrical or competitive) are thought to be responsible for the spin-glass system. For SMMs and SCMs, the strong uniaxial magnetic anisotropy (where the zero-field splitting parameter D < 0) and the large spin values of the ground states (for SCMs, one can say that the total spin number ST =∞) are two main reasons for the very slow relaxation in these systems. In long-range ordered magnets, such as ferromagnets or ferrimagnets, the relaxation can also be induced by the dynamics of domain walls, such as domain-wall displacement and the domain magnetization rotation and so on. In order to obtain a magnetic ground-state for a chain, individual magnetic moments cannot cancel out. This condition can be satisfied if the chain is ferromagnetic (e.g., [[FeL(CN)4]4Co(H2O)x] (L= 2,2′-bipyridine or 1,10-phenanthroline, x = 1 or 2), and [Co(bt)(N3)2] (bt = 2,2′-bithiazoline)) or ferrimagnetic, such as [Co(hfacac)2(NITPhOMe)]. [3a] There is another way to achieve this goal in an antiferromagnetic chain: the spin-canting that arises from the non-colinear spin arrangements because of the existence of an antisymmetrical component of the superexchange interaction (Dzyaloshinsky– Moriya interaction, DMI) or the appropriate anisotropy. Such is the case in the reported SCM of Co(H2L)(H2O) (H4L= 4-Me-C6H4-CH2N(CH2PO3H2)2). [3g]

Four new metal-organic polymers with SCN–/N3– anion bridges and flexible long spacers L {L = bim [1,2-bis(imidazol-1-yl)ethane] and bte [1,2-bis(1,2,4-triazol-1-yl)ethane]}, [Co(SCN)2(bim)] (1-Co), [Co(SCN)2(bte)] (2-Co), [Mn(N3)2(bte)] (3-Mn), and [Mn(N3)2(bim)] (4-Mn), were synthesized and characterized by single-crystal X-ray diffraction studies and their magnetic properties were investigated. Complex 1-Co is a triple-bridging chain complex with double end-to-end SCN– anions and single gauche-bim spacers as bridges. Complexes 2-Co and 3-Mn both contain 1D chains bridged by double end-to-end SCN– or N3– anions and these chains are further extended to 2D (4,4) layers by the anti-bte spacers. Complex 4-Mn has a topological 3D diamond structure constructed through 1D double end-on azide-bridged MnII chains and extended through the anti-bim spacers. Magnetic measurements reveal that 1-Co and 3-Mn remain paramagnetic; the dominant magnetic coupling between CoII is weak ferromagnetic and that between MnII is strong antiferromagnetic. As for 2-Co and 4-Mn, they show metamagnetic behavior below TN = 2.9 and 3.0 K, respectively. Our results show that a combination of the short anion bridges (SCN–/N3–) and flexible bidentate long spacers can be used to construct coordination polymers with novel topologies and interesting magnetic properties. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Poly(vinyl alcohol) (PVA), PVA/nanocellulose fiber (CNF) and PVA/CNF/graphene oxide (GO) films were prepared simply by casting stable aqueous mixed solutions. FTIR investigation indicated that hydrogen bonding existed between the interface of GO and PVA-CNF. Scanning electron microscopy and X-ray diffraction analysis showed that GO was uniformly dispersed in PVA-CNF matrix. Introducing CNF into PVA caused a significant improvement in tensile strength, and further incorporating GO into PVA/CNF matrix led to a further increase. The tensile strength of the neat PVA film, PVA/CNF composite, and PVA/CNF/GO film (0.6 wt % GO) was 43 MPa, 69 MPa, and 80 MPa, respectively. Moreover, when incorporating 8 wt % CNF into PVA matrix, O2 permeability and water absorption decreased from 13.36 to 11.66 cm3/m2/day, and from 164.2% to 98.8%, respectively. Further adding 0.6 wt % GO into PVA/CNF matrix resulted in a further decrease of permeability and water absorption to 3.19 cm3/m2/day and 91.2%, respectively. Furthermore, for all composite samples, the transmittance of visible light was higher than 67% at 800 nm. CNF and GO-reinforced PVA with high mechanical and barrier properties are potential candidates for packaging industry. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45345.

The combination of some three-atom bridges with paramagnetic 3d transition metal ions results in the systematic isolation of molecular magnetic materials, ranging from single-molecule and single-chain magnets to layered weak ferromagnets and three-dimensional porous magnets. The design strategy and role of secondary components, such as co-ligands, templates and other mixed short ligands are discussed.

A new complex (1) of Prussian blue analogue with the composition of K0.2Mn1.4Cr(CN)6·6H2O was prepared and characterized structurally as well as magnetically. The crystal structure of complex 1 was...

Two novel 3d−5d Cu(II)−W(V) cyano-bridged compounds, [Cu(tn)]3[W(CN)8]2·3H2O (1) and [Cu(pn)]3[W(CN)8]2·3H2O (2), where tn is 1,3-diaminopropane and pn is 1,2-diaminopropane, have been synthesized and characterized structurally and magnetically. The X-ray analyses of the two complexes reveal that they exhibit two-dimensional layer structures with the following crystal data: space group P21/c, a = 24.459(5) A, b = 9.6426(19) A, c = 18.037(4) A, β = 90.45(3)°, V = 4253.9(15) A3, Z = 4 for 1; and space group P21/c, a = 24.126(5) A, b = 9.8889(19) A, c = 18.077(3) A, β = 90.204(4)°, V = 4312.9(14) A3, and Z = 4 for 2. Magnetic properties of the two compounds have also been investigated. Both show typical metamagnetic behavior. The critical field at which the interlayer antiferromagnetic ground-state switches to a ferromagnetic state is ∼1.25 T for 1 and 0.35 T for 2 at 1.8 K.