Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• UV irradiation without a photoinitiator [176][177]. Grafted polymers and untethered polymers are generated simultaneously in the presence of a monomer. Ionizing radiation including high-energy photons (X-rays and γ-rays) and charged α- or β-particles generate charged particles, especially electrons

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• [40]. BPNs were tested as NIR photoinitiator for the CuAAC reactions of low molar mass compounds and polymers possessing antagonist azide and alkyne functionalities (Figure 1). The optical absorption spectra of BPNs, copper(I) chloride (CuICl, 0.05 mmol) and copper(II) chloride (CuIICl2, 0.05 mmol

• , and elemental mapping images (Supporting Information File 1, Figures S5 and S6). This behavior is expected since BPNs are immobilized between the interconnected chains in the cross-linked structure. Conclusion In conclusion, we have demonstrated the use of BPNs as an efficient photoinitiator for the

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• , g-CN as an organic semiconductor is utilized in polymerization processes as a photoinitiator by generation of reactive radical species (O2−•, HO•, HO2•) under convenient light illumination. The ability of g-CN to initiate polymerization and act as a polymerization locus for a covalent polymer growth

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• , McGinniss and co-workers reported the polymerization of methyl methacrylate (26, MMA) by employing 4,4’-bis(N,N-diethylamino)benzophenone (27, DEABP) as the photoinitiator (Scheme 7) [35]. It was already well-accepted that aminoaromatic compounds, such as Michler’s ketone (28) and DEABP (27), present large

• aldehydes and ketones were studied in the photografting of acrylic acids. In 1988, Allméar and co-workers, while studying the grafting of acrylic acid (34) onto high- or low-density polyethylene and polystyrene using benzophenone as the photoinitiator and acetone (4) as the solvent, observed that the

• grafting was possible even in the absence of benzophenone due to acetone (4), but at a slower rate [39]. Later, Kubota and co-workers found that acetone (4) could act as an efficient photoinitiator for photografting, in contrast to other aliphatic ketones [40]. In 2004, Wang and co-workers also observed

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DPAP). The lipophilic scaffold hepta-1,6-dien-4-yl tetradecanotate (6, Scheme 2) was obtained from hepta-1,6-dien-4-ol and served for the preparation of compounds 7 and 8. Hepta-1,6-dien-4-ol was prepared according to experimental procedures previously reported

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

• networks. Keywords: photoinitiator; photopolymerization; photoredox catalysis; photoredox catalyst; Introduction Photopolymerization reactions are now widely used both in industry and in academic laboratories. These processes usually lead to the transformation of a liquid resin in a 3D solid polymer upon

• interest in the past few decades. The development of photoredox catalysts is one of the major advances. 1.1 Photoinitiating system (PIs) Photoinitiated polymerization processes are polymerizations initiated by light irradiation. For that, a photoinitiator (PI) or a photoinitiating system (PIs) is mixed

• or visible range with high molar extinction coefficients are actively researched. As far as the extractability of the photoinitiators and the side-products that can be formed during the polymerization process is concerned, a good strategy is to reduce the amount of photoinitiator. Thus, inspired by

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• catalyst-free thiol–yne coupling (TYC) reaction. TYC has gained large attention as a representative of the click chemistry concept [17]. In the TYC reaction, usually a photoinitiator creates thiyl radicals [18][19][20], which react with nearby alkyne moieties to form covalent sulfur–carbon bonds and vinyl

• )methane, TPM-SH) and a small amount of photoinitiator (2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropan-1-one) [26]. Afterwards we irradiated the substrate using a standard UV lamp at a wavelength of 365 nm for 3 minutes. We then rinsed the substrate thoroughly with absolute THF and immersed the

• substrate in a solution of the tetra-topic alkyne building block (tetrakis(4-ethynylphenyl)methane, TPM-alkyne), again with a small amount of photoinitiator. Then we irradiated the substrate for 3 minutes and rinsed the substrate thoroughly with absolute THF. Figure 1 shows the LbL synthesis procedure as

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• conditions for enzyme catalysis afforded nice polymers. The obtained polymers could be cross-linked by UV light in the presence of the solid photoinitiator Iracure 270 to form hard films [69]. Several poly(amine-co-ester)s were synthesized directly from dicarboxylic acid diesters and N-alkyl- or N

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• for the synthesis of carboxylated PEG SCPs PEG microparticles were synthesized by precipitation polymerization in a similar manner as described in ref. [9]. Briefly, PEG-diacrylamide (Mn = 8000 Da) [26] (50 mg, 6.3 µmol) was dispersed in a 1 M sodium sulfate solution (10 mL). The UV photoinitiator

Investigations of thiol-modified phenol derivatives for the use in thiol–ene photopolymerizations

• Sebastian Reinelt,
• Monir Tabatabai,
• Urs Karl Fischer,
• Norbert Moszner,
• Andreas Utterodt and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 1733–1740, doi:10.3762/bjoc.10.180

• photopolymerizations the widely used monomer PETMP was used as reference monomer [22][23][33]. As the initiating compound, the newly developed photoinitiator di(4-methoxy)benzoyl(diethyl)germane (K69) was utilized since recent studies showed an excellent performance of K69 in dental materials compared to

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

• of the PIs and PISs [45][46][47][48][49][50][51][52][53][54][55]. This approach opened up [45][46][47][48][49][50][51][52][53] a new way for the design of a novel high performance class of PIs for FRP and FRPCP (where the photoinitiator is now referred as a photoinitiator catalyst PIC). It brings

• , among others, the following novel properties [45][46][47][48][49][50][51][52][53][54][55]: Almost no photoinitiator is consumed. Since the spectral photosensitivity extends now from the UV to the visible, laser excitation in the purple, blue, yellow, green or red is feasible. Low light intensities (as

• -butylnitrone (PBN) according to a procedure described in detail in [15]. The ESR spectra simulations were carried out with the PEST WINSIM program. Results and Discussion Possible usable strategies for the design of PICs in the photopolymerization area Oxidizable photoinitiator catalysts Using oxidizable

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

• ). There is also an usual cationic polymerization (CP; r3 in Scheme 1) [1][2]. When the PIs exhibit a catalytic behavior analogous to a photocatalyst (PC) in organic chemistry, they are designed as photoinitiator catalysts (PIC). PIs as well as PICs are based on pure organic, that is, metal free, or

Intramolecular bridges formed by photoswitchable click amino acids

• Christian Hoppmann,
• Ronald Kühne and
• Michael Beyermann

Beilstein J. Org. Chem. 2012, 8, 884–889, doi:10.3762/bjoc.8.100

• peptides were synthesized as described in [6]. Thiol–ene coupling was performed at a peptide concentration of 0.1 mM in the presence of the photoinitiator 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (0.5 equiv) and TCEP·HCl (1.0 equiv) in degassed buffered solution containing 50

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

• Branislav Husár,
• Norbert Moszner and
• Ivan Lukáč

Beilstein J. Org. Chem. 2012, 8, 337–343, doi:10.3762/bjoc.8.37

• (CQ) in the presence of H-atom donors such as ethers (H abstraction), or more efficiently tertiary amines (electron/proton transfer), is known to be an effective photoinitiator for curing methacrylate-based dental restorative resins [1][2][3][4][5][6][7][8][9]. CQ photochemistry in solution in the

Synthesis, characterization and photoinduced curing of polysulfones with (meth)acrylate functionalities

• Cemil Dizman,
• Sahin Ates,
• Lokman Torun and
• Yusuf Yagci

Beilstein J. Org. Chem. 2010, 6, No. 56, doi:10.3762/bjoc.6.56

• -dimethoxy-2-phenylacetophenone (DMPA) as the photoinitiator undergo rapid polymerization upon irradiation forming insoluble networks. The photo-curing behavior was investigated by photo-DSC and the effects of the molecular weight of the polysulfone precursor and type of functionality on the rate of

• )acrylate telechelics with polysulfone backbones. The curing behavior of these telechelics was studied by photo-DSC with 2,2-dimethoxy-2-phenylacetophenone (DMPA) as the photoinitiator. As shown below, the rigid aromatic polysulfones with different molecular weights were deliberately used so as to

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• , and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations. Keywords: adhesives; dental polymers; dimethacrylates; photoinitiator; radical polymerization; Introduction Self