This Collaborative Research Activities in Environmental Molecular Science initiative engages a cohesive group of researchers in chemistry and environmental engineering in studies pertaining to redox reactions of organohalides (R-X compounds). Motivation for this work stems from the challenges posed by organohalide pollutants. Of the top 25 organic contaminants identified in groundwater in the U.S., 17 are organohalides. There is currently an acute problem associated with organohalide contamination at DOE sites , which comprise a combined area of two million acres. Organohalides also contribute to stratospheric ozone depletion and global climate change. On the positive side, halogenated organic compounds serve importantand beneficial roles in the chemical/pharmaceutical industries and will continue to do so, and it is therefore essential to find means for minimizing their deleterious environmental effects. This project describes an interdisciplinary effort brought together by a common goal: to obtain a molecular-level understanding of redox-mediated R-X bond cleavage (dehalogenation), from which "greener" chemical processes can be developed. The CRAMES initiative is a 5-year, NSF-funded endeavor involving five research groups from John Hopkins University, four are from Chemistry and one is from Environmental Engineering. Together, they are addressing dehalogenation chemistry through their combined expertise in synthesis, homogeneous and heterogeneous catalysis, biomimetic and bioinorganic chemistry, electrochemistry, surface science, and environmental chemistry, and form a collaborative group that fosters new ventures in research and education. The objectives of the project are: 1) to carry out research which pertains to new R-X reductive or oxidative dehalogenation chemistries and which elucidates fundamental molecular mechanisms of organohalide transformations; 2) to apply these findings to develop novel approaches for sensing these contaminants, remediating such pollutants, and for predicting their environmental fate; and 3) to provide a pedagogical program that informs and educates the next generation of environmental chemists. Together with our industrial/National Laboratory collaborators, the participants have the complementary expertise required to achieve the stated goals. These interactions will facilitate transfer of technologies for solving "real world" environmental problems. The fundamental research emphasizes R-X reactions with redox-active metal-containing species. Thus, new coordination complexes and chemistry of copper(I) and metalloporphyrinoid complexes are being developed, emphasizing reactivity studies and fundamental mechanistic investigations of both reductive and oxidative R-X cleavage; stoichiometric and (electro)catalytic processes are being investigated. Photo-triggered and electrochemical dehalogenation will also be examined, particularly with certain copper(I) or iron(II) macrocyclic compounds. Investigations of molecular photoremediation in solid-state materials will be carried out, and new photoinitiated studies will provide unique approaches to mechanistic insights on very fast time scales. Also planed are detailed mechanistic studies of dehalogenation promoted by bimetallic reductants and metal sulfide minerals that have application in "engineered" treatment systems and in natural attenuation of organohalides. Surface science methods will be used to determine the structure of solid-state catalyst materials and stoichiometric reagents for R-X cleavage. In addition, a potentially useful remediation strategy, electron-beam induced chlorocarbon reductive cleavage, will be examined in condensed media (water/ice). This research therefore offers great promise for identifying better means for destroying organohalide contaminants, for monitoring their presence, and for predicting rates and products of natural removal processes. A particularly important aspect of this research is in the education of future scientists on important environmental issues. An extensive outreach program will be established through local universities that includes undergraduate research projects, and environmental seminar series, and new courses within the existing Johns Hopkins University curriculum will be developed. Links have been forged with nearby Universities, Morgan State (Baltimore) and Howard (Washington, D.C.). An opportunity for participants to conduct environmental research with National Laboratory collaborators and to interact with industry to tackle practical problems is also provided. The JHU CRAEMS initiative will also include dissemination of results at regular on-campus symposia, national and local meetings, and through a web site.