Lokale Agenda 21 Anforderungen und Problemlagen fuer eine Evaluation Nachhaltiger Entwicklung in Kommunen

Lokale Agenda 21-Prozesse sind in oesterreichischen und deutschen Kommunen in den vergangenen Jahren zu einer verbreiteten kommunalen Handlungsstrategie fuer eine Nachhaltige Entwicklung geworden. Damit einhergehend ist der Bedarf an einer wissenschaftlich fundierten Begleitung und Beurteilung dieser Prozesse gestiegen. Die Evaluation Nachhaltiger Entwicklung und Lokaler Agenda 21 ist jedoch mit einer Vielzahl theoretischer, konzeptioneller, methodischer und forschungspraktischer Problemlagen und Fragestellungen verbunden. Der vorliegende Beitrag stellt den Versuch dar, die Spannweite der Fragen und Probleme im Zusammenhang mit der Evaluation Lokaler Agenda 21-Prozesse aufzuzeigen und zu systematisieren. Im Vordergrund stehen die Analyse von Leitfaeden als Unterstuetzung, die Theorie der Evaluation von Lokalen Agenda 21-Prozessen sowie die konkrete Evaluationspraxis, welche exemplarisch fuer das Berliner Koordinatorenmodell beschrieben wird. (ICI2)Available from Bibl. des HWWA Hamburg(H3)-A01-2653 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

An Interdisciplinary Approach to Understanding the Open City

Cities worldwide are being confronted with perpetual economic challenges, flows of migration, and increasing vulnerability to the consequences of global changes. Within contemporary urban lines of conflict, the ‘open city’ has resurfaced in urban scholarship as a potential guiding principle to the contradictory tendencies and calamities of cities. Despite the often approving and positivist take on the concept, the open city is not a homogeneous concept, and a variety of understandings – that are mostly limited to a specific discipline – are in circulation. These different understandings evoke a range of associations, leading to different interpretations of the concept and potentially conflicting properties associated with the term. Within the Open City: Theories, Perspectives, Instruments research project, we propose an interdisciplinary framework, which derives insights of openness from spatial, socio-economic and temporal dimensions, to systemise different understandings of openness and relate them to each other. To do so, we use a research design based on the method of assemblage that allows a variety of perspectives on the same research object. This paper presents how the outcomes of different disciplinary perspectives and research methodologies have been assembled to reach conclusions on the theoretical debate regarding the concept of openness and to further develop tools for the practical use of the open city concepts

Hydroalumination of 1,8-Diethynylanthracenes–Al-based Bis-Lewis-Acids and their Isomerization and Complexation Behavior

Aders N, Trapp P, Lamm J-H, et al. Hydroalumination of 1,8-Diethynylanthracenes–Al-based Bis-Lewis-Acids and their Isomerization and Complexation Behavior. Organometallics. 2022

Gas-phase equilibrium molecular structures and ab initio thermochemistry of anthracene and rubrene

Otlyotov A, Kurochkin IY, Minenkov Y, et al. Gas-phase equilibrium molecular structures and ab initio thermochemistry of anthracene and rubrene. Physical Chemistry Chemical Physics. 2022.Semi-experimental gas-phase structures of anthracene and rubrene (5,6,11,12-tetraphenyltetracene) were determined by means of gas electron diffraction (GED). The use of the flexible restraints in the refinement of the GED data successfully resolves non-equivalent C–C bond lengths. The tetracene core of an isolated rubrene molecule was found to exhibit twist distortion of about 18°; this is less than DFT calculations predict (30–40°). The modified Feller-Peterson-Dixon method in conjunction with high-level DLPNO-CCSD(T) calculations was employed to resolve the discrepancy between the available experimental gas-phase enthalpies of formation for rubrene. The theoretical value of ΔfHmo(g, 298 K) = 759.4 ± 5.9 kJ mol−1 meets its recent experimental counterpart (765.6 ± 8.4 kJ mol−1) and is in strong disagreement with the previous estimation (882 kJ mol−1)

Halogen Bonds of Halotetrafluoropyridines in Crystals and Co-crystals with Benzene and Pyridine.

Mitzel NW, Trapp P, Stammler H-G, et al. Halogen Bonds of Halotetrafluoropyridines in Crystals and Co-crystals with Benzene and Pyridine. Chemistry . 2019;25(30):7339-7350.The structures of the three para-substituted halotetrafluoropyridines with chlorine, bromine and iodine have been determined in the solid state (X-ray diffraction). The structures of these compounds and that of pentafluoropyridine were also determined in the gas phase (electron diffraction). Structures in the solid state of the bromine and iodine derivative exhibit halogen bonding as a structure deter-mining motif. On the way to an investigation on the formation of the halogen bond of halotetrafluoropyridines in the solid state with the stronger Lewis base, e.g. a better halogen-bond acceptor, pyridine, co-crystals of benzene adducts were investigated. These co-crystals show halogen bonding only for the two heavier halotetrafluoropyridi-nes. In the pyridine co-crystals halogen bonding was observed for all three para-halotetrafluoropyridines. The formation of homodimers and heterodimers with pyridine is also supported by quantum-chemical calculations of electron-density topologies and natural-bond orbitals. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim