Search results for "showcase"
showing 5 items of 5 documents
Developments in the dehydrogenative electrochemical synthesis of 3,3′,5,5′-tetramethyl-2,2′-biphenol
2021
Abstract The symmetric biphenol 3,3′,5,5′‐tetramethyl‐2,2′‐biphenol is a well‐known ligand building block and is used in transition‐metal catalysis. In the literature, there are several synthetic routes for the preparation of this exceptional molecule. Herein, the focus is on the sustainable electrochemical synthesis of 3,3′,5,5′‐tetramethyl‐2,2′‐biphenol. A brief overview of the developmental history of this inconspicuous molecule, which is of great interest for technical applications, but has many challenges for its synthesis, is provided. The electro‐organic method is a powerful, sustainable, and efficient alternative to conventional synthesis to obtain this symmetric biphenol up to the …
Strain Release Chemistry of Photogenerated Small‐Ring Intermediates
2021
Abstract Photochemical processes, such as isomerizations and cycloadditions, have proven to be very useful in the construction of highly strained molecular frameworks. Photoinduced ring strain enables subsequent exergonic reactions which do not require the input of additional chemical energy and provides a variety of attractive synthetic options leading to complex structures. This review covers the progress achieved in the application of sequences combining excitation by ultraviolet light to form strained intermediates, which are further transformed to lower energy products in strain‐release reactions. As ring strain is considerable in small ring systems, photogenerated three‐ and four‐memb…
Risk indexes evaluation in view of a new showcase designing of “L’Annunciata” by Antonello da Messina
2018
Museums are often hosted by heritage buildings, where the indoor thermal conditions are usually subjected to a free-floating regime, due to the difficulty of equipping them with HVAC systems that, generally, are highly impacting tools from a visual point of view. These technological tools, in fact, could conflict with the established arrangement of the works of art. This would represent a problem, since the indoor physical conditions of these premises must fall within the ranges of values suitable to ensure the safety of the works of art there exhibited. In addition, the increasing time spent by visitors inside museums (now offering various possibilities of leisure, ranging from the book sh…
Delphi: dall'omphalos cosmico al Museo Archeologico
2009
The permanent exhibition in the Archaeological Museum, which focuses on the history of the Delphic temenos and the events related to the famous oracle and omphalos, is analyzed through the complex and delicate relationship which the contemporary museum building has established with his context, as the archaeological site of Delphi can be read as an open-air museum, which was able to accumulate and settle inside its perimeter, in a variety of declinations, the architecture and the art of ancient Hellas.
Structural Motifs of Alkali Metal Superbases in Non‐coordinating Solvents
2020
Abstract Lochmann–Schlosser superbases (LSB) are a standard reagent in synthetic chemistry to achieve an exchange of a proton on an organic framework with an alkali metal cation, which in turn can be replaced by a wide range of electrophilic groups. In standard examples, the deprotonating reagent consists of an equimolar mixture of n‐butyllithium and potassium t‐butoxide. However, the nature of the reactive species could not be pinned down either for this composition or for similar mixtures with comparable high reactivity. Despite the poor solubility and the fierce reactivity, some insights into this mixture were achieved by some indirect results, comparison with chemically related systems,…