34 research outputs found

    {2-[Bis(2,4-di-tert-butyl­phen­oxy)phosphan­yloxy-κP]-3,5-di-tert-butyl­phenyl-κC 1}[(1,2,5,6-η)-cyclo­octa-1,5-diene]rhodium(I) toluene monosolvate

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    The reaction of (η3-all­yl)[(1,2,5,6-η)-cyclo­octa-1,5-diene]rhodium(I) with tris­(2,4-di-tert-butyl­phen­yl)phosphite in toluene produces the title compound, [Rh(C42H62O3P)(C8H12)]·C7H8, by spontaneous metallation at one of the nonsubstituted phenyl ortho-C atoms of the phosphite mol­ecule. The coordination geometry at the RhI ion is distorted square-planar. The toluene solvent mol­ecule is disordered over two different orientations, with site-occupation factors of 0.810 (2) and 0.190 (2)

    Dicarbonyl­{3,3′-di-tert-butyl-5,5′-di­meth­oxy-2,2′-bis­[(4,4,5,5-tetra­phenyl-1,3,2-dioxa­phospho­lan-2-yl)­oxy-κP]biphen­yl}hydridorhodium(I) diethyl ether monosolvate

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    In the title compound, [Rh(C74H68O8P2)H(CO)2]·C4H10O, the C2HP2 coordination set at the RhI ion is arranged in a distorted trigonal–planar geometry with one P atom of the diphosphite mol­ecule and the H atom adopting the axial coordination sites

    Synthesis of C2-Symmetric Diphosphormonoamidites and Their Use as Ligands in Rh-Catalyzed Hydroformylation: Relationships between Activity and Hydrolysis Stability

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    A series of diphosphoramidites has been synthetized with a piperazine, homopiperazine, and an acyclic 1,2-diamine unit in the backbone. New compounds were tested alongside related N-acyl phosphoramidites as ligands in the Rh-catalyzed hydroformylation of n-octenes to investigate their influence on the activity and regioselectivity. A subsequent study of their hydrolysis stability revealed that the most stable ligands induced the highest activity in the catalytic reaction

    Preliminary Results for the Multi-Robot, Multi-Partner, Multi-Mission, Planetary Exploration Analogue Campaign on Mount Etna

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    This paper was initially intended to report on the outcome of the twice postponed demonstration mission of the ARCHES project. Due to the global COVID pandemic, it has been postponed from 2020, then 2021, to 2022. Nevertheless, the development of our concepts and integration has progressed rapidly, and some of the preliminary results are worthwhile to share with the community to drive the dialog on robotics planetary exploration strategies. This paper includes an overview of the planned 4-week campaign, as well as the vision and relevance of the missiontowards the planned official space missions. Furthermore, the cooperative aspect of the robotic teams, the scientific motivation, the sub task achievements are summarised

    Finally! Insights into the ARCHES Lunar Planetary Exploration Analogue Campaign on Etna in summer 2022

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    This paper summarises the first outcomes of the space demonstration mission of the ARCHES project which could have been performed this year from 13 june until 10 july on Italy’s Mt. Etna in Sicily. After the second postponement related to COVID from the initially for 2020 planed campaign, we are now very happy to report, that the whole campaign with more than 65 participants for four weeks has been successfully conduced. In this short overview paper, we will refer to all other publication here on IAC22. This paper includes an overview of the performed 4-week campaign and the achieved mission goals and first results but also share our findings on the organisational and planning aspects

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    {2-[Bis(2,4-di-tert-butylphenoxy)phosphanyloxy-κP]-3,5-di-tert-butylphenyl-κC1}{3,3′-di-tert-butyl-5,5′-dimethoxy-2,2′-bis[(1,1,2,2-tetraphenylethane-1,2-dioxy)phosphanyloxy-κP]biphenyl}rhodium(I) toluene-d8 2.7-solvate

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    The molecule of the title compound, [Rh(C42H62O3P)(C74H68O4P2]·2.7C7D8, consists of two phospharhodacyclic substructures sharing the Rh atom, which are formed by coordination/ortho-metallation of a triaryl phosphite, and by the coordination of a rigid bisphosphite, respectively. The metal displays a tetrahedrally distorted square-planar coordination geometry. A tert-butyl group shows rotational disorder over two positions with refined site occupancy of 0.561 (3):0.439 (3). Two partial-occupancy toluene solvent molecules are disordered over two orientations with site occupancies of 0.5:0.3 and 0.5:0.4, respectively. Intramolecular C—H...O hydrogen bonds are observed. In the crystal, complex molecules and toluene solvent molecules pack as alternating layers parallel to the ac plane

    Effects of Substitution Pattern in Phosphite Ligands Used in Rhodium-Catalyzed Hydroformylation on Reactivity and Hydrolysis Stability

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    The stability of homogeneous catalytic systems is an industrially crucial topic, which, however, receives comparatively little attention from academic research. Phosphites are among the most frequently used ligands in industrial, rhodium-catalyzed n-regioselective hydroformylation. However, they are particularly vulnerable to hydrolysis. Since the decomposition of ligands should be dependent on the substitution patterns, phenyl, tert-butyl and condensed ring systems of benzopinacolphosphites were evaluated concerning their activity, regioselectivity and hydrolysis stability. A series of twelve strongly related phosphites were synthesized, tested in the hydroformylation of isomeric n-octenes, and studied in hydrolysis experiments using in situ NMR spectroscopy. Our results show that substituents in the ortho-position, especially tert-butyl substituents, enhance hydrolysis stability while maintaining compelling activity and regioselectivity. In contrast, substituents in the para-position may destabilize the phosphite
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