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In this study, we describe a synthetic method for incorporating arenes into closed tubes that we name capsularenes. First, we prepared vase-shaped molecular baskets 4-7. The baskets comprise a benzene base fused to three bicycle[2.2.1]heptane rings that extend into phthalimide (4), naphthalimide (6), and anthraceneimide sides (7), each carrying a dimethoxyethane acetal group. In the presence of catalytic trifluoroacetic acid (TFA), the acetals at top of 4, 6 and 7 change into aliphatic aldehydes followed by their intramolecular cyclization into 1,3,5-trioxane (

An unprecedented redox-neutral S-nitrosation of thiol has been achieved at dicopper(I,I) center. Treatment of dicopper (I,I) complex with excess NO• and thiol generates a dicopper (I,I) di-S-nitrosothiol complex [CuICuI(RSNO)2]2+ or dicopper (I,I) mono-S-nitrosothiol complex [CuICuI(RSNO)]2+, which readily release RSNO in 88-94% yield. The S-nitrosation reaction proceeds through a mixed-valence [CuIICuIII(m-O)(m-NO)]2+ species, which deprotonates RS-H at the basic m-O site and nitrosates the RS- at the m-NO site. The [CuIICuIII(m-O)(m-NO)]2+ complex is also competent for O-nitrosation of MeOH, which is isoelectronic to thiol. In this case, a rare [CuIICuII(m-NO)(OMe)]2+ intermediate has been isolated and fully characterized, suggesting the S-nitrosation proceeds through the intermediary of analogous [CuIICuII(m-NO)(SR)]2+ species. The redox- and proton-neutral S-nitrosation process reported here represents the first functional model of ceruloplasmin in mediating S-nitrosation of external thiols, adding further implications for biological copper sites in the interconversion of NO•/RSNO.

Covalent capsule 1 was designed to include two molecular baskets linked with three mobile pyridines tucked into its inner space. On the basis of both theory (DFT) and experiments (NMR and X-ray crystallography), we found that the pyridine "doors" split the chamber (380 A3 ) of 1 so that two equally sizeable compartments (190 A3 ) became joined through a conformationally flexible aromatic barrier. The compartments of such unique host could be populated with CCl4 (88 A3 ; PC=46 %), CBr4 (106 A3 ; 56 %) or their combination CCl4 /CBr4 (PC=51 %), with thermodynamic stabilities ΔG° tracking the values of packing coefficients (PC). Halogen (C-X⋅⋅⋅π) and hydrogen bonding (C-H⋅⋅⋅X) contacts held the haloalkane guests in the cavities of 1. The consecutive complexations were found to occur in a negative allosteric manner, which we propose to result from the induced-fit mode of complexation. Newly designed 1 opens a way for probing the effects of inner conformational dynamics on noncovalent interactions, reactivity and intramolecular translation in confined spaces of hollow molecules.

Anthropogenic and natural forest disturbance cause ecological damage and carbon emissions. Forest disturbance in the Amazon occurs in the form of deforestation (conversion of forest to non-forest land covers), degradation from the extraction of forest resources, and destruction from natural events. The crucial role of the Amazon rainforest in the hydrologic cycle has even led to the speculation of a disturbance "tipping point" leading to a collapse of the tropical ecosystem. Here we use time series analysis of Landsat data to map deforestation, degradation, and natural disturbance in the Amazon Ecoregion from 1995 to 2017. The map was used to stratify the study area for selection of sample units that were assigned reference labels based on their land cover and disturbance history. An unbiased statistical estimator was applied to the sample of reference observations to obtain estimates of area and uncertainty at biennial time intervals. We show that degradation and natural disturbance, largely during periods of severe drought, have affected as much of the forest area in the Amazon Ecoregion as deforestation from 1995 to 2017. Consequently, an estimated 17% (1,036,800 ± 24,800 km2 , 95% confidence interval) of the original forest area has been disturbed as of 2017. Our results suggest that the area of disturbed forest in the Amazon is 44%-60% more than previously realized, indicating an unaccounted for source of carbon emissions and pervasive damage to forest ecosystems.

Relative to other cyclic poly-phosphorus species (that is, cyclo-Pn ), the planar cyclo-P4 group is unique in its requirement of two additional electrons to achieve aromaticity. These electrons are supplied from one or more metal centers. However, the degree of charge transfer is dependent on the nature of the metal fragment. Unique examples of dianionic mononuclear η4 -P4 complexes are presented that can be viewed as the simple coordination of the [cyclo-P4 ]2- dianion to a neutral metal fragment. Treatment of the neutral, molybdenum cyclo-P4 complexes Mo(η4 -P4 )I2 (CO)(CNArDipp2 )2 and Mo(η4 -P4 )(CO)2 (CNArDipp2 )2 with KC8 produces the dianionic, three-legged piano stool complexes, [Mo(η4 -P4 )(CO)(CNArDipp2 )2 ]2- and [Mo(η4 -P4 )(CO)2 (CNArDipp2 )]2- , respectively. Structural, spectroscopic, and computational studies reveal a similarity to the classic η6 -benzene complex (η6 -C6 H6 )Mo(CO)3 regarding the metal-center valence state and electronic population of the planar-cyclic ligand π system.

Elemental white phosphorus (P4 ) is well recognized as a critical precursor to organophosphorus compounds. However, regulatory constraints stemming from the toxic and pyrophoric nature of white phosphorus have significantly limited its accessibility. Herein is described a new approach to white phosphorus storage and release based on a unique example of photolytic reductive elimination of the tetrahedral P4 molecule from a mononuclear cyclo-P4 molybdenum complex. The latter functions as an air-stable, chemically-deactivated source of white phosphorus. The system features efficient photo-release of white phosphorus using inexpensive violet LED sources. Additionally, high-yield recapture of unspent white phosphorus by the molybdenum center can be achieved by post-photolysis heating at convenient temperatures.

Multimetallic clusters have long been investigated as molecular surrogates for reactive sites on metal surfaces. In the case of the μ4 -nitrido cluster [Fe4 (μ4 -N)(CO)12 ]- , this analogy is limited owing to the electron-withdrawing effect of carbonyl ligands on the iron nitride core. Described here is the synthesis and reactivity of [Fe4 (μ4 -N)(CO)8 (CNArMes2 )4 ]- , an electron-rich analogue of [Fe4 (μ4 -N)(CO)12 ]- , where the interstitial nitride displays significant nucleophilicity. This characteristic enables rational expansion with main-group and transition-metal centers to yield unsaturated sites. The resulting clusters display surface-like reactivity through coordination-sphere-dependent atom rearrangement and metal-metal cooperativity.

The encumbered tetraisocyanide dianion Na2 [Fe(CNArMes2 )4 ] reacts with two molecules of CO2 to effect reductive disproportionation to CO and carbonate ([CO3 ]2- ). When the reaction is performed in the presence of silyl triflates, reductive disproportionation is arrested by silylative esterification of a mono-CO2 adduct. This results in the formation of four-coordinate terminal iron carbynes possessing an aryl carbamate substituent owing to the direct attachment of an C(O)OSiR3 group to an isocyanide nitrogen atom. Crystallographic, spectroscopic, and computational analyses of these iron-carbon multiply bonded species reveal electronic structure properties indicative of a conformationally locked iron carbyne unit.

While interest in cooperative reactivity of transition metals and Lewis acids is receiving significant attention, the scope of known reactions that directly exploit the polarized reverse-dative σ-bond of metal-borane complexes (i.e., M→BR3) remains limited. Described herein is that the platinum (boryl)iminomethane (BIM) complex [Pt(κ2-N,B-Cy2BIM)(CNArDipp2)] can effect the oxidative insertion of a range of unsaturated organic substrates, including azides, isocyantes, and nitriles, as well as CO2 and elemental sulfur (S8). In addition, alkyl migration processes available to the BIM framework allow for post-insertion reaction sequences resulting in product release from the metal center.

One of the least understood aspects of the world-wide ‘greening of markets’ (Kuhn 2005) is the emergence of local ‘ethical marketplaces’ and the sub-set of alternative business models described as ‘ethical businesses’ (Henderson 2006; Gibson-Graham 2008; Williams 2015). But previous research has demonstrated the ability of local politicians to encourage their regions toward more ethical marketplaces (Malpass et al. 2007). This paper explores the impact radical centrist third-party representation has on the emergence of ethical businesses across Great Britain. To understand this relationship, we utilize a novel dataset of organizations with membership in Ethical Junction, the UK’s largest network for ethical businesses. We use a zero-inflated Poisson regression to model the connection, and find a meaningful relationship, between third-party political representation on British local councils and the presence of ethical businesses within local authorities. This presents an example of the way in which radical political change may be part of a wider social movement towards greening markets.

Two novel ruthenium complexes, [Ru(2,2′-bipyridine-6,6′-diphosphonato)(pic)2] (2) (pic=4-picoline) and [Ru(6,6′-diisopropyl-2,2′-bipyridine-6,6′-diphosphonato)(pic)2] (3) bearing phosphonate groups have been synthesized and characterized by NMR spectroscopy, elemental analyses, X-ray crystallography, cyclic voltammetry, and UV/Vis spectroscopy. Both complexes show catalytic water oxidation activity by electrochemistry. At pH 7, the RuII/III redox couple of 2 is observed at a lower potential than that of 3, yet significantly, 3 oxidizes water at a lower onset potential. At pH 1 however, 2 and 3 have comparable catalytic reactivity using sacrificial oxidant CeIV. We propose that water oxidation activities of 2 and 3 are influenced by overall charges. For example, in oxidizing from RuII to RuIII at pH 7, 2 acquires a −1 overall charge whereas 3 acquires a +1 charge. Charge-dictated electrostatic effects may govern binding of a water molecule to the metal site.

With over 30 years of directly comparable Landsat satellite observations now freely available, and new imagery being added to the Landsat archive every day, Landsat time series analysis affords novel opportunities for ecosystem mapping, environmental monitoring and comparative ecology. This study presents a series of data-driven examples that illustrate the potential of using Landsat time series to further the study of land cover characterization, vegetation phenology and landscape dynamics. Our goal is to showcase how ecosystem properties and dynamics manifest in the Landsat data record, laying the foundation for better integration of remote sensing and ecology using Landsat time series. Our results suggest that time series provide valuable information on ecosystem cover, use and condition that could advance understanding of ecosystem function, resilience and dynamics. We have only just begun to understand how to use the complete record of Landsat observations for the study of ecology, and we hope this work will encourage future studies on quantifying and analyzing relationships between time series data, ecosystems and ecological processes.

Scorpionate chemistry has long featured sandwich complexes with two trispyrazolylborate (Tp) or two bispyrazolylborate (Bp) ligands coordinated to a transition metal. Less common are complexes in which one Tp and one Bp ligand are coordinated to the metal. We report herein five such complexes of NiII, MnII, CoII, or FeII involving Tp and Bp ligands comprising either 3-phenyl-4-cyanopyrazole or 3-phenylpyrazole, as well as a related CoII complex with two Tp ligands, one of which is coordinated in a κ2 fashion. All complexes feature an agostic interaction with a B–H hydrogen atom.

Summary The development of genomic markers is described for Nile tilapia, Oreochromis niloticus, using the Diversity Arrays Technology (DArT) genotype-by-sequencing platform. A total of 13 215 single nucleotide polymorphism (SNP) markers and 12 490 silicoDArT (dominant) markers were identified from broodstock of two selective breeding programs [Genetically Improved Farmed Tilapia (GIFT) strain from Malaysia and the Abbassa strain from Egypt]. Over 10 000 SNPs were polymorphic in either strain, and 2985 and 3087 showed strain-specific polymorphisms for the GIFT and Abbassa strains respectively. We demonstrate the potential utility of these markers for rapid genomic screening and use in breeding programs.