Mohamad Ali Tehfe

Bio: Mohamad Ali Tehfe is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Photopolymer & Flash photolysis. The author has an hindex of 6, co-authored 7 publications receiving 452 citations.

N‐Heterocyclic Carbene Boranes Accelerate Type I Radical Photopolymerizations and Overcome Oxygen Inhibition

Abstract: To protect and serve: The efficiency of TypeI radical photoinitiators for acrylate polymerization is greatly increased by the presence of NHC-boranes. Conversion of the initially photogenerated radicals, R . (see scheme), into strongly nucleophilic NHC-boryl radicals, through hydrogen-atom transfer, gives a better matched radical for subsequent reaction with monomer, ensuring better initiation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photosensitized Formation of Phosphorus-Centered Radicals: Application to the Design of Photoinitiating Systems

Abstract: The processes involved in the photosensitized decomposition of phosphorus-containing compounds in the presence of a photoinitiator PI were investigated and characterized by laser flash photolysis, electron spin resonance, and molecular modeling (density functional theory calculations). They lie on (i) a photoinitiator/phosphorus-containing compound electron transfer from phosphinites a, b and phosphites c, leading to a phosphoniumyl radical ion R3P•+ or a photoinitiator/phosphorus-containing compound hydrogen abstraction reaction from labile P–H bonds in phosphine oxides d, phosphonates e, and trialkylphosphine salts f, g and (ii) the subsequent production of phosphorus centered radicals P• in a–e and a radical ion P•+ in f, g. The interaction rate constants for the key processes (photoinitiator/phosphorus-containing compound, alkoxyl radical/phosphorus-containing compound, and peroxyl radical/phosphorus-containing compound), the associated transient absorption, and electron spin resonance–spin trapping s...

Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment

Abstract: Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

Light-Controlled Radical Polymerization: Mechanisms, Methods, and Applications

Abstract: The use of light to mediate controlled radical polymerization has emerged as a powerful strategy for rational polymer synthesis and advanced materials fabrication. This review provides a comprehensive survey of photocontrolled, living radical polymerizations (photo-CRPs). From the perspective of mechanism, all known photo-CRPs are divided into either (1) intramolecular photochemical processes or (2) photoredox processes. Within these mechanistic regimes, a large number of methods are summarized and further classified into subcategories based on the specific reagents, catalysts, etc., involved. To provide a clear understanding of each subcategory, reaction mechanisms are discussed. In addition, applications of photo-CRP reported so far, which include surface fabrication, particle preparation, photoresponsive gel design, and continuous flow technology, are summarized. We hope this review will not only provide informative knowledge to researchers in this field but also stimulate new ideas and applications to further advance photocontrolled reactions.

Photoinduced Electron Transfer Reactions for Macromolecular Syntheses

Abstract: Photochemical reactions, particularly those involving photoinduced electron transfer processes, establish a substantial contribution to the modern synthetic chemistry, and the polymer community has been increasingly interested in exploiting and developing novel photochemical strategies. These reactions are efficiently utilized in almost every aspect of macromolecular architecture synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Merging with polymerization techniques, photochemistry has opened up new intriguing and powerful avenues for macromolecular synthesis. Construction of various polymers with incredibly complex structures and specific control over the chain topology, as well as providing the opportunity to manipulate the reaction course through spatiotemporal control, are one of the unique abilities of such photochemical reactions. This review paper provides a comprehensive account of the fundamentals and applications ...

Light-Controlled Radical Polymerization: Mechanisms, Methods, and Applications

Abstract: The use of light to mediate controlled radical polymerization has emerged as a powerful strategy for rational polymer synthesis and advanced materials fabrication. This review provides a comprehensive survey of photocontrolled, living radical polymerizations (photo-CRPs). From the perspective of mechanism, all known photo-CRPs are divided into either (1) intramolecular photochemical processes or (2) photoredox processes. Within these mechanistic regimes, a large number of methods are summarized and further classified into subcategories based on the specific reagents, catalysts, etc., involved. To provide a clear understanding of each subcategory, reaction mechanisms are discussed. In addition, applications of photo-CRP reported so far, which include surface fabrication, particle preparation, photoresponsive gel design, and continuous flow technology, are summarized. We hope this review will not only provide informative knowledge to researchers in this field but also stimulate new ideas and applications to further advance photocontrolled reactions.

Photocatalysis in organic and polymer synthesis

Abstract: This review, with over 600 references, summarizes the recent applications of photoredox catalysis for organic transformation and polymer synthesis. Photoredox catalysts are metallo- or organo-compounds capable of absorbing visible light, resulting in an excited state species. This excited state species can donate or accept an electron from other substrates to mediate redox reactions at ambient temperature with high atom efficiency. These catalysts have been successfully implemented for the discovery of novel organic reactions and synthesis of added-value chemicals with an excellent control of selectivity and stereo-regularity. More recently, such catalysts have been implemented by polymer chemists to post-modify polymers in high yields, as well as to effectively catalyze reversible deactivation radical polymerizations and living polymerizations. These catalysts create new approaches for advanced organic transformation and polymer synthesis. The objective of this review is to give an overview of this emerging field to organic and polymer chemists as well as materials scientists.