scholarly journals Recent Advances on Copper Complexes as Visible Light Photoinitiators and (Photo) Redox Initiators of Polymerization

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 953 ◽  
Author(s):  
Guillaume Noirbent ◽  
Frédéric Dumur
Keyword(s):  
Organic Chemistry ◽  
Excited State ◽  
Visible Light ◽  
Metal Complexes ◽  
Copper Complexes ◽  
Low Cost ◽  
Iridium Complexes ◽  
Solid Materials ◽  
Photo Polymerization ◽  
Synthetic Approaches

Metal complexes are used in numerous chemical and photochemical processes in organic chemistry. Metal complexes have not been excluded from the interest of polymerists to convert liquid resins into solid materials. If iridium complexes have demonstrated their remarkable photochemical reactivity in polymerization, their high costs and their attested toxicities have rapidly discarded these complexes for further developments. Conversely, copper complexes are a blooming field of research in (photo) polymerization due to their low cost, easy syntheses, long-living excited state lifetimes, and their remarkable chemical and photochemical stabilities. Copper complexes can also be synthesized in solution and by mechanochemistry, paving the way towards the synthesis of photoinitiators by Green synthetic approaches. In this review, an overview of the different copper complexes reported to date is presented. Copper complexes are versatile candidates for polymerization, as these complexes are now widely used not only in photopolymerization, but also in redox and photoassisted redox polymerization processes.

scholarly journals Determination of the Lowest Excited State of Metal Complexes of Dipyrido[3, 2-a:2′,3′-c]Phenazine

1999 ◽  
Vol 19 (1-4) ◽  
pp. 287-289
Author(s):  
Mark R. Waterland ◽  
Keith C. Gordon
Keyword(s):  
Raman Spectroscopy ◽  
Excited State ◽  
Metal Complexes ◽  
Excited States ◽  
Copper Complexes ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Time Resolved ◽  
State Data

The nature of the lowest excited state of rhenium and copper complexes of dipyrido[3,2- a:2′ ,3′-c]phenazine (Dppz) has been determined using Resonance Raman, Time- Resolved Resonance Raman Spectroscopy and Spectroelectrochemistry. Comparison of spectroelectrochemical data and excited state data show that for the complexes studied no reduced ligand bands are observed in the excited state spectra thus the lowest excited states are all Ligand Centred in nature. The use of substituents at the 11 and/or 12 position of the ligand has no effect on the excited state ordering.

Aryl-substituted Triarsiranes: Synthesis and Reactivity

2020 ◽  
Author(s):  
André Schumann ◽  
Jonas Bresien ◽  
Malte Fischer ◽  
Christian Hering-Junghans
Keyword(s):  
Organic Chemistry ◽  
Electronic Structure ◽  
Heterocyclic Carbenes ◽  
Synthetic Approaches ◽  
Inorganic And Organic

Cyclotriarsanes are rare and limited synthetic approaches have hampered reactivity studies on these systems. Described in here is a scalable synthetic protocol towards (AsAr)<sub>3</sub> (Ar = Dip, 2,6-<sup>i</sup>Pr<sub>2</sub>-C<sub>6</sub>H<sub>3</sub>; Tip, 2,4,6-<sup>i</sup>Pr<sub>3</sub>-C<sub>6</sub>H<sub>2</sub>), which allowed to study their reactivity towards [Cp<sub>2</sub>Ti(C<sub>2</sub>(SiMe<sub>3</sub>)<sub>2</sub>], affording titanocene diarsene complexes and towards N-heterocyclic carbenes (NHCs) to give straightforward access to a variety of NHC-arsinidene adducts. The electronic structure of the titanium diarsene complxes has been studied and they are best described as Ti(IV) species with a doubly reduced As<sub>2</sub>Ar<sub>2</sub> ligand. These findings will make (AsAr)<sub>3</sub> valuable precursors in the synthetic inorganic and organic chemistry.

scholarly journals Unprecedented Coordination-Induced Bright Red Emission from Group 12 Metal-Bound Triarylazoimidazoles

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1739
Author(s):  
Artyom A. Astafiev ◽  
Olga V. Repina ◽  
Boris S. Tupertsev ◽  
Alexey A. Nazarov ◽  
Maria R. Gonchar ◽  
...  
Keyword(s):  
Visible Light ◽  
Metal Complexes ◽  
Scientific Literature ◽  
Photo Luminescence ◽  
Red Emission ◽  
The Past ◽  
Highly Efficient ◽  
Luminescence Emission ◽  
New Family ◽  
Group 12

Arylazoimidazoles are important dyes which were intensively studied in the past. In contrast, triarylazoimidazoles (derivatives which carry aryl substituents at the imidazole core) received almost no attention in the scientific literature. Here, we report a new family of simple and easily accessible triarylazoimidazole-group 12 metal complexes, which feature highly efficient photo-luminescence emission (Φ up to  0.44). Novel compounds exhibit bright red emission in solution, which could be excited with a visible light.

Solution Processed Sb2S3-based Photocathode with Enhanced Photocatalytic Performance via Constructing Ultrathin TiO2 Overlayer and Noble Metal Modification

2021 ◽  
Author(s):  
Yanwen Wang ◽  
Rong Liang ◽  
Chao Qin ◽  
Lei Ren ◽  
Zhizhen Ye ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
Light Response ◽  
Solution Processed ◽  
Antimony Sulfide ◽  
Visible Light Response ◽  
Absorbing Material

Antimony sulfide (Sb2S3) is a light absorbing material with strong visible light response, which is suitable for efficient and low-cost photoelectrodes. Nano-structured films have unique advantages in constructing photoelectrodes due...

scholarly journals Effect of Photoinitiator on Precursory Stability and Curing Depth of Thiol-Ene Clickable Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1877
Author(s):  
Kai-Hung Yang ◽  
Gabriella Lindberg ◽  
Bram Soliman ◽  
Khoon Lim ◽  
Tim Woodfield ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Rheological Properties ◽  
Swelling Ratio ◽  
Sodium Persulfate ◽  
Photo Polymerization ◽  
Gelation Kinetics ◽  
The Stability ◽  
Over Time

Recent advances highlight the potential of photopolymerizable allylated gelatin (GelAGE) as a versatile hydrogel with highly tailorable properties. It is, however, unknown how different photoinitiating system affects the stability, gelation kinetics and curing depth of GelAGE. In this study, sol fraction, mass swelling ratio, mechanical properties, rheological properties, and curing depth were evaluated as a function of time with three photo-initiating systems: Irgacure 2959 (Ig2959; 320–500 nm), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP; 320–500 nm), and ruthenium/sodium persulfate (Ru/SPS; 400–500 nm). Results demonstrated that GelAGE precursory solutions mixed with either Ig2959 or LAP remained stable over time while the Ru/SPS system enabled the onset of controllable redox polymerization without irradiation during pre-incubation. Photo-polymerization using the Ru/SPS system was significantly faster (<5 s) compared to both Ig2959 (70 s) and LAP (50 s). Plus, The Ru/SPS system was capable of polymerizing a thick construct (8.88 ± 0.94 mm), while Ig2959 (1.62 ± 0.49 mm) initiated hydrogels displayed poor penetration depth with LAP (7.38 ± 2.13 mm) in between. These results thus support the use of the visible light based Ru/SPS photo-initiator for constructs requiring rapid gelation and a good curing depth while Ig2959 or LAP can be applied for photo-polymerization of GelAGE materials requiring long-term incubation prior to application if UV is not a concern.

scholarly journals Panchromatic Copper Complexes for Visible Light Photopolymerization

Photochem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 167-189
Author(s):  
Alexandre Mau ◽  
Guillaume Noirbent ◽  
Céline Dietlin ◽  
Bernadette Graff ◽  
Didier Gigmes ◽  
...  
Keyword(s):  
Free Radical ◽  
Visible Light ◽  
Radical Polymerization ◽  
Copper Complexes ◽  
Free Radical Polymerization ◽  
Photoluminescence Properties ◽  
System Formation ◽  
Iodonium Salt ◽  
Visible Light Photopolymerization ◽  
Cationic Polymerizations

In this work, eleven heteroleptic copper complexes were designed and studied as photoinitiators of polymerization in three-component photoinitiating systems in combination with an iodonium salt and an amine. Notably, ten of them exhibited panchromatic behavior and could be used for long wavelengths. Ferrocene-free copper complexes were capable of efficiently initiating both the radical and cationic polymerizations and exhibited similar performances to that of the benchmark G1 system. Formation of acrylate/epoxy IPNs was also successfully performed even upon irradiation at 455 nm or at 530 nm. Interestingly, all copper complexes containing the 1,1′-bis(diphenylphosphino)ferrocene ligand were not photoluminescent, evidencing that ferrocene could efficiently quench the photoluminescence properties of copper complexes. Besides, these ferrocene-based complexes were capable of efficiently initiating free radical polymerization processes. The ferrocene moiety introduced in the different copper complexes affected neither their panchromatic behaviors nor their abilities to initiate free radical polymerizations.

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