Mechanism of Ni-Catalyzed Photochemical Halogen Atom-Mediated C(sp)-H Arylation.

Within the context of Ni photoredox catalysis, halogen atom photoelimination from Ni has emerged as a fruitful strategy for enabling hydrogen atom transfer (HAT)-mediated C(sp)-H functionalization. Despite the numerous synthetic transformations invoking this paradigm, a unified mechanistic hypothesis that is consistent with experimental findings on the catalytic systems and accounts for halogen radical formation and facile C(sp)-C(sp) bond formation remains elusive. We employ kinetic analysis, organometallic synthesis, and computational investigations to decipher the mechanism of a prototypical Ni-catalyzed photochemical C(sp)-H arylation reaction.

Big events, little change: Extreme climatic events have no region-wide effect on Great Barrier Reef governance.

Extreme climatic events trigger changes in ecosystems with potential negative impacts for people. These events may provide an opportunity for environmental managers and decision-makers to improve the governance of social-ecological systems, however there is conflicting evidence regarding whether these actors are indeed able to change governance after extreme climatic events. In addition, the majority of research to date has focused on changes in specific policies or organizations after crises.

Governing complexity: Integrating science, governance, and law to manage accelerating change in the globalized commons.

The speed and uncertainty of environmental change in the Anthropocene challenge the capacity of coevolving social-ecological-technological systems (SETs) to adapt or transform to these changes. Formal government and legal structures further constrain the adaptive capacity of our SETs. However, new, self-organized forms of adaptive governance are emerging at multiple scales in natural resource-based SETs.

Coerced regimes: management challenges in the Anthropocene.

Management frequently creates system conditions that poorly mimic the conditions of a desirable self-organizing regime. Such management is ubiquitous across complex systems of people and nature and will likely intensify as these systems face rapid change. However, it is highly uncertain whether the costs (unintended consequences, including negative side effects) of management but also social dynamics can eventually outweigh benefits in the long term.