Sustainable Urban Systems: Co-design and Framing for Transformation

Rapid urbanisation generates risks and opportunities for sustainable development. Urban policy and decision makers are challenged by the complexity of cities as social–ecological–technical systems. Consequently there is an increasing need for collaborative knowledge development that supports a whole-of-system view, and transformational change at multiple scales. Such holistic urban approaches are rare in practice. A co-design process involving researchers, practitioners and other stakeholders, has progressed such an approach in the Australian context, aiming to also contribute to international knowledge development and sharing. This process has generated three outputs: (1) a shared framework to support more systematic knowledge development and use, (2) identification of barriers that create a gap between stated urban goals and actual practice, and (3) identification of strategic focal areas to address this gap. Developing integrated strategies at broader urban scales is seen as the most pressing need. The knowledge framework adopts a systems perspective that incorporates the many urban trade-offs and synergies revealed by a systems view. Broader implications are drawn for policy and decision makers, for researchers and for a shared forward agenda

Computational studies of the solid-state molecular organometallic (SMOM) chemistry of Rh σ-alkane complexes

A review of computational studies on the structures, bonding and reactivity of rhodium σ-alkane complexes in the solid state is presented. These complexes of the general form [(R2P(CH2)nPR2)Rh(alkane)][BArF 4] (where ArF = 3,5-(CF3)2C6H3) are formed via solid/gas hydrogenation of alkene precursors, often in single-crystal-to-single-crystal (SC-SC) transformations. Molecular and periodic density functional theory (DFT) calculations complement experimental characterisation techniques (X-ray, solid-state NMR) to provide a detailed picture of the structure and bonding in these species. These σ-alkane complexes exhibit reactivity in the solid state, undergoing fluxional processes, and access different alkane binding modes that link to C-H activation and H/D exchange. The mechanisms of several of these processes have been defined using periodic DFT calculations which provide excellent quantitative agreement with the available experimental activation barriers. A comparison of computed results derived from periodic DFT calculations, where the full solid-state environment is taken into account, with simple model calculations using the isolated molecular cations highlights the importance of modelling the solid state to reproduce the structures of these alkane complexes. The solid-state environment can also have a significant impact on the computed reaction energetics