Photochemistry. In their Communication (e202303435), Tsuyoshi Mita et al. report a method for the diphosphination of 1.1.1propellane using visible light.
The history of the IUPAC Photochemistry Committee since its creation in 1976 and its transition in 2001 to the IUPAC Photochemistry Sub-Committee are reviewed as well as the connections of Committee ...and Sub-Committee to the various photochemical associations (
uropean
hotochemical
ssociation,
,
nter-
merican
hotochemical
ociety,
and
sian and Oceanian
hotochemistry
ssociation,
). The participants in both the Commission and the Sub-Committee over the years are listed as well as the Recommendations and Technical Reports produced since the creation of the Committee until the present days.
We present and analyze the results of a pharmaceutical industry-wide survey of the strategies and approaches that companies have for implementing photochemical reactions in discovery chemistry, ...process development, and commercial manufacturing. The survey questions encompass the types of photochemical reactions that pharmaceutical companies pursue and why, the types of reactors (batch and flow) used, how they are characterized for photochemistry, scale-up of photochemical reactions, and how companies prioritize resources for developing photochemical reactions, among other topics. The survey focuses on many of these topics from the perspectives of discovery chemists and process scientists to highlight similarities and differences between their approaches on the specific photochemical transformations and materials of construction used in photochemical reactors. The survey results clearly demonstrate that photochemistry is a viable synthetic strategy for producing active pharmaceutical ingredients (APIs), from discovery all the way to commercialization. While photochemistry is more prevalent for discovery and early stage process development, the survey results indicate that more companies are leveraging photochemistry in successful scale-ups in later stages of process development, often using flow chemistry, and have significant knowledge resulting from these experiences. Nevertheless, there still are gaps to adopting photochemical reactions across stages of development and companies have very limited experience discussing photochemistry with regulatory agencies. Overall, the survey results demonstrate that photochemistry offers considerable benefits for synthesizing APIs and developing API processes, such as greenness and sustainability, shortening synthetic routes, and potential for improved product quality.
Presents the state of the technology, from fundamentals to new materials and applications Today's electronic devices, computers, solar cells, printing, imaging, copying, and recording technology, to ...name a few, all owe a debt to our growing understanding of the photophysics and photochemistry of polymeric materials. This book draws together, analyzes, and presents our current understanding of polymer photochemistry and photophysics. In addition to exploring materials, mechanisms, processes, and properties, the handbook also highlights the latest applications in the field and points to new developments on the horizon. Photochemistry and Photophysics of Polymer Materials is divided into seventeen chapters, including: Optical and luminescent properties and applications of metal complex-based polymers Photoinitiators for free radical polymerization reactions Photovoltaic polymer materials Photoimaging and lithographic processes in polymers Photostabilization of polymer materials Photodegradation processes in polymeric materials Each chapter, written by one or more leading experts and pioneers in the field, incorporates all the latest findings and developments as well as the authors' own personal insights and perspectives. References guide readers to the literature for further investigation of individual topics. Together, the contributions represent a series of major developments in the polymer world in which light and its energy have been put to valuable use. Not only does this reference capture our current state of knowledge, but it also provides the foundation for new research and the development of new materials and new applications.
Photoelectrochemical Hydrogen Production Krol, Roel van de; Grätzel, Michael
Kluwer international series in electronic materials: science and technology,
2011, 2011-11-08, Letnik:
102
eBook
Odprti dostop
Photoelectrochemical Hydrogen Production describes the principles and materials challenges for the conversion of sunlight into hydrogen through water splitting at a semiconducting electrode. Readers ...will find an analysis of the solid state properties and materials requirements for semiconducting photo-electrodes, a detailed description of the semiconductor/electrolyte interface, in addition to the photo-electrochemical (PEC) cell. Experimental techniques to investigate both materials and PEC device performance are outlined, followed by an overview of the current state-of-the-art in PEC materials and devices, and combinatorial approaches towards the development of new materials. Finally, the economic and business perspectives of PEC devices are discussed, and promising future directions indicated. Photoelectrochemical Hydrogen Production is a one-stop resource for scientists, students and RD practitioners starting in this field, providing both the theoretical background as well as useful practical information on photoelectrochemical measurement techniques. Experts in the field benefit from the chapters on current state-of-the-art materials/devices and future directions.
The use of flow photochemistry and its apparent superiority over batch has been reported by a number of groups in recent years. To rigorously determine whether flow does indeed have an advantage over ...batch, a broad range of synthetic photochemical transformations were optimized in both reactor modes and their yields and productivities compared. Surprisingly, yields were essentially identical in all comparative cases. Even more revealing was the observation that the productivity of flow reactors varied very little to that of their batch counterparts when the key reaction parameters were matched. Those with a single layer of fluorinated ethylene propylene (FEP) had an average productivity 20 % lower than that of batch, whereas three‐layer reactors were 20 % more productive. Finally, the utility of flow chemistry was demonstrated in the scale‐up of the ring‐opening reaction of a potentially explosive 1.1.1 propellane with butane‐2,3‐dione.
Spot the difference! By careful matching of reaction parameters, the performance of 13 different photochemical reactions were compared in both batch and flow reactors. Surprisingly, the yields obtained in the different reactor modes were essentially identical. Similarly, the productivity differences between the two reactor modes, under the same time scales, were relatively small (see figure).
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