Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• that inhibits cationic polymerization of epoxides [5]. Though conjugate acids are formed according to the routes shown in Scheme 6, cationic photopolymerization only succeeded with aziridines [5]. The different reaction mechanism occurring with such monomers explains these different observations [92

• photoproducts were formed and cationic photopolymerization even of epoxides succeeded with good conversions vide infra. Additional absorbers fitting in this scheme comprise at the meso-position alternative substituents such as Phenyl or Chlorine (see Table 1 for comparison). Surprisingly, this reaction has not

• provides some reviews and original articles discussing mechanistic details [5][6][11][12][13][14][54][63][64][67][85]. NIR sensitized cationic photopolymerization Equations 1–7 responsibly affect the efficiency of cationic photopolymerization. This was first demonstrated in 2016 [5] taking a combination of

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• of C2 from [80]. Characteristics of A3 [81]. Characteristics of 4CzIPN [69][82][83]. Free radical polymerization performances with metal-based and metal-free photocatalysts [46][53][58][63][80][81][99]. Cationic photopolymerization performance with metal-based and metal-free photoredox catalysts [46

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

• Jacques Lalevée,
• Sofia Telitel,
• Pu Xiao,
• Marc Lepeltier,
• Frédéric Dumur,
• Fabrice Morlet-Savary,
• Didier Gigmes and
• Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

• introduced into the polymer photochemistry field (area) in the very past years (see a review in [15][16][17][18][19][20][21][22]). Indeed, in this area, free-radical photopolymerization (FRP, Scheme 1, reactions 1 and 2), cationic photopolymerization (CP, Scheme 1, reactions 3 and 4), free-radical promoted

• cationic photopolymerization (FRPCP, Scheme 1, reactions 5–7) or acid and base-catalyzed photocrosslinking (reactions 8 and 9) are initiated using photoinitiators (PI) which generate reactive species (radicals, cations, anions, radical cations, acids, bases). These PIs are often incorporated into

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• experiments. The mechanisms involved in the initiation step are discussed, and relationships between the core structure, the Co_Py absorption property, and the polymerization ability are tentatively proposed. Keywords: cationic photopolymerization; free-radical-promoted cationic photopolymerization

• Eox(Py_9) > Ered(Iod) (Table 1). The formation of radical cations can be worthwhile to initiate cationic polymerization at room temperature (see below). Ability of the different pyrene structures in photopolymerization reactions Cationic photopolymerization (CP) The ring-opening polymerization

• r5 and r6 and (iv) the ability of Co_Py•+ to initiate a ring-opening polymerization process. Structure–reactivity relationships for the different derivatives can hardly be extracted. This is probably ascribed to a strong interplay between (i) to (iv). A cationic photopolymerization profile of EPOX