NEWS OF THE W EEK
CO2 EMISSIONS AND IMPERILED SPECIES CLIMATE CHANGE: Agencies g nix use of Endangered g Species p Act to regulate coal-fired power plants
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N THREE MEMOS released this month, the Environ-
mental Protection Agency and two federal wildlife agencies contend that when making regulatory decisions they need not consider the climate-change impact on endangered species. Specifically, the memos address carbon dioxide emissions from coal-fired power plants. The memos support recent Bush Administration statements and proposed regulatory changes to the Endangered Species Act (ESA) that would block the Fish & Wildlife Service and the National Marine Fisheries Service from considering the impact of greenhouse gas emissions from a single large CO2 source on endangered species. J OHN & KAREN HOLLINGSWORTH/US FWS
Climate-change impacts on endangered species such as the gray wolf will not be considered in the Bush Administration’s permitting decisions for coalfired power plants.
PLATINUM OXO COMPLEX ISOLATED ORGANOMETALLIC CHEMISTRY:
Compound p is stable without electron-withdrawing ligands
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N ISRAELI TEAM reports preparing an elusive
late-transition-metal oxo complex, in which platinum is doubly bonded to oxygen, without the use of electron-withdrawing ligands to stabilize the electron-rich metal (Nature 2008, 455, 1093). Such complexes have been proposed as intermediates in ceres, catalytic transformations, and industrial oxidation reactions, and the new compound could shed light ELUSIVE SPECIES on how these systems um oxo complex work. out electronTransition-metal withdrawing groups oxo complexes are (C is black, Pt is pink, characterized by a P is orange, O is red, multiple bond beand N is blue). tween oxygen and the WWW.CE N-ONLI NE .ORG
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This is a sharp reversal for the wildlife agencies, says Kassie Siegel, an attorney with the Center for Biological Diversity, an environmental group. “Under ESA, agencies that approve large sources of greenhouse gas emissions must analyze the impact of these emissions just like they analyze anything else that impacts endangered species,” she says. The memos have limited regulatory authority, but they show that the three agencies will not consider the impact on species of CO2 emissions from several dozen coal-fired power plants being proposed across the U.S. In an Oct. 3 memo, EPA uses as a model its permitting decision for the proposed Desert Rock power plant in New Mexico, a huge 1,500-MW coal-fired power plant to be built on Navajo tribal land. In approving that project, EPA did not consider ESA, and primarily for that reason, the state, environmental groups, and Native American organizations are challenging the decision. EPA argues that it is scientifically impossible to use modeling programs to determine the direct or indirect impacts of CO2 emissions from Desert Rock or other sources on a specific species or habitat. It then says the cumulative effects “are of no relevance” because impacts cannot be determined. Within days of receiving EPA’s memo, the two other agencies issued letters of agreement. Siegel points out, however, that only last year, the Fish & Wildlife Service noted in a letter to EPA that seven endangered species may be affected by the Desert Rock project and urged EPA to supply additional information.—JEFF JOHNSON
metal. Late transition metals, such as platinum, silver, and gold, are packed with d electrons, making their oxo complexes so reactive that it wasn’t until the 1990s that one was isolated. Until now, all late-transition-metal oxo complexes with d-electron-rich metals, such as platinum, have used electron-withdrawing ligands to stabilize the molecule. By reacting a pincer complex of platinum with dioxirane, David Milstein and coworkers at Weizmann Institute of Science were able to generate a platinum oxo complex that’s stable at room temperature, even though it contains no electron-withdrawing ligands. Milstein’s group couldn’t obtain a crystal structure of the complex, but they verified the structure through exhaustive analytical, computational, and reactive analyses. Milstein’s findings “go a long way to substantiating the previous reports of platinum, palladium, and gold oxo complexes,” Emory University chemistry professor Craig L. Hill notes in a commentary that accompanies the report. “This, in turn, makes it hard to argue that latetransition-metal oxo complexes don’t exist, as might reasonably have been argued before on the basis of conventional wisdom about modes of bonding. On the contrary, it seems that they might be fairly widespread. They can certainly now be regarded as realistic candidates for intermediates in many important catalytic reactions that involve oxygen.”—BETHANY HALFORD
OCTOBE R 27, 20 08
