Hung Out to Dry: Choice of Priority Ecoregions for Conserving Threatened Neotropical Anurans Depends on Life-History Traits

Background: In the Neotropics, nearly 35 % of amphibian species are threatened by habitat loss, habitat fragmentation, and habitat split; anuran species with different developmental modes respond to habitat disturbance in different ways. This entails broad-scale strategies for conserving biodiversity and advocates for the identification of high conservation-value regions that are significant in a global or continental context and that could underpin more detailed conservation assessments towards such areas. Methodology/Principal Findings: We identified key ecoregion sets for anuran conservation using an algorithm that favors complementarity (beta-diversity) among ecoregions. Using the WWF’s Wildfinder database, which encompasses 700 threatened anuran species in 119 Neotropical ecoregions, we separated species into those with aquatic larvae (AL) or terrestrial development (TD), as this life-history trait affects their response to habitat disturbance. The conservation target of 100 % of species representation was attained with a set of 66 ecoregions. Among these, 30 were classified as priority both for species with AL and TD, 26 were priority exclusively for species with AL, and 10 for species with TD only. Priority ecoregions for both developmental modes are concentrated in the Andes and in Mesoamerica. Ecoregions important for conserving species with AL are widely distributed across the Neotropics. When anuran life histories were ignored, species with AL were always underrepresented in priority sets

Investigation on the reactivity of tetranuclear Group 7/8 mixed-metal clusters toward triphenylphosphine

Reactions of the tetranuclear mixed-metal clusters ReM3(CO)13(µ3-thpymS) (1, M = Os; 2, M = Ru; thpymSH = tetrahydropyrimidine-2-thiol) with PPh3 are examined. At room temperature reaction between 1 and PPh3 in the presence Me3NO leads to the formation of mono- and bis-phosphine substituted clusters ReOs3(CO)12(PPh3)(µ3-thpymS) (3) and ReOs3(CO)11(PPh3)2(µ3-thpymS) (4). Cluster 3 also reacts with PPh3 under similar conditions to give 4. In contrast, a similar reaction between 2 and PPh3 furnishes only the mono-phosphine substituted clusters ReRu3(CO)12(PPh3)(µ3-thpymS) (3). All the new clusters have been characterized by analytical and spectroscopic data together with single crystal X-ray diffraction for 1, 3 and 5

Reactivity of triruthenium thiophyne and furyne clusters: competitive S-C and P-C bond cleavage reactions and the generation of highly unsymmetrical alkyne ligands

The synthesis and reactivity of the thiophyne and furyne clusters [Ru-3(CO)(7)(mu-dppm)(mu(3)-eta(2)-C4H2E){mu-P(C4H3E)(2)}(mu-H)] (E = S, O) is reported. Addition of P(C4H3E)(3) to [Ru-3(CO)(10)(mu-dppm)] (1) at room temperature in the presence of Me3NO gives simple substitution products [Ru-3(CO)(9)(mu-dppm)-P(C4H3E)(3)}] (E = S, 2; E = O, 3). Mild thermolysis in the presence of further Me3NO affords the thiophyne and furyne complexes [Ru-3(CO)(7)(mu-dppm)(mu(3)-eta(2)-C4H2E){mu-P(C4H3E)(2)}(mu-H)] (E = S, 4; E = O, 6) resulting from both carbon-hydrogen and carbon-phosphorus bond activation. In each the C4H2E (E = S, O) ligand donates 4-electrons to the cluster and the rings are tilted with respect to the m-dppm and the phosphido-bridged open triruthenium unit. Heating 4 at 80 degrees C leads to the formation of the ring-opened cluster [Ru-3(CO)(5)(mu-CO)(mu-dppm)(mu(3)-eta(3)-SC4H3){mu-P(C4H3S)(2)}] (5) resulting from carbon-sulfur bond scission and carbon- hydrogen bond formation and containing a ring-opened mu(3)-eta(3)-1-thia-1,3-butadiene ligand. In contrast, a similar thermolysis of 3 affords the phosphinidene cluster [Ru-3(CO)(7)(mu-dppm)(mu(3)-eta(2)-C4H2O){mu(3)-P(C4H3O)}] (7) resulting from a second phosphorus-carbon bond cleavage and (presumably) elimination of furan. Treatment of 4 and 6 with PPh3 affords the simple phosphine-substituted products [Ru-3(CO)(6)(PPh3)(mu-ppm)(mu(3)-eta(2)-C4H2E){mu-P(C4H3E)(2)}(mu-H)] (E = S, 8; E = O, 9). Both thiophyne and furyne clusters 4 and 6 readily react with hydrogen bromide to give [Ru-3(CO)(6)Br(mu-Br)(mu-dppm)(mu(3)-eta(2)-eta(1)-C4H2E){mu-P(C4H3E)(2) }(mu-H)] (E = S, 10; E = O, 11) containing both terminal and bridging bromides. Here the alkynes bind in a highly unsymmetrical manner with one carbon acting as a bridging alkylidene and the second as a terminally bonded Fisher carbene. As far as we are aware, this binding mode has only previously been noted in ynamine complexes or those with metals in different oxidation states. The crystal structures of seven of these new triruthenium clusters have been carried out, allowing a detailed analysis of the relative orientations of coordinated ligands