D. Cambié, C. Bottecchia, N. J. Straathof, V. Hessel, and T. Noël, Chem. Rev, vol.116, pp.10276-10341, 2016.

S. Shi, C. Croutxé-barghorn, and X. Allonas, Prog. Polym. Sci, vol.65, pp.1-41, 2017.

J. Lalevée and J. Fouassier, Dyes and Chomophores in Polymer Science, 2015.

K. Ueno, T. Oshikiri, Q. Sun, X. Shi, and H. Misawa, Chem. Rev, vol.118, pp.2955-2993, 2018.

M. H. Shaw, J. Twilton, and D. W. Macmillan, J. Org. Chem, vol.81, pp.6898-6926, 2016.

N. Corrigan, S. Shanmugam, J. Xu, and C. Boyer, Chem. Soc. Rev, vol.45, pp.6165-6212, 2016.

S. Dadashi-silab, S. Doran, and Y. Yagci, Chem. Rev, vol.116, pp.10212-10275, 2016.

N. Zivic, M. Bouzrati-zerelli, A. Kermagoret, F. Dumur, J. Fouassier et al., ChemCatChem, vol.8, pp.1617-1631, 2016.

J. Chen and W. R. Browne, Coord. Chem. Rev, vol.374, pp.15-35, 2018.

J. Lalevee and J. Fouassier, Photopolymerisation Initiating Systems, 2018.

T. Brömme, D. Oprych, J. Horst, P. S. Pinto, B. Strehmel et al., , vol.5, pp.69915-69924, 2015.

C. Schmitz, A. Halbhuber, D. Keil, and B. Strehmel, Prog. Org. Coat, vol.100, pp.32-46, 2016.

B. Strehmel, S. Ernst, K. Reiner, D. Keil, H. Lindauer et al., Z. Für Phys. Chem, vol.228, pp.129-153, 2014.

C. Kütahya, C. Schmitz, V. Strehmel, Y. Yagci, and B. Strehmel, Angew. Chem. Int. Ed, vol.57, pp.7898-7902, 2018.

S. Shanmugam, J. Xu, and C. Boyer, Angew. Chem. Int. Ed, vol.55, pp.1036-1040, 2016.

N. Corrigan, J. Xu, and C. Boyer, Macromolecules, vol.49, pp.3274-3285, 2016.

I. Janowska, J. Zakrzewski, K. Nakatani, J. A. Delaire, M. Palusiak et al., J. Organomet. Chem, vol.675, pp.35-41, 2003.

I. Janowska, J. Zakrzewski, K. Nakatani, M. Palusiak, M. Walak et al., J. Organomet. Chem, vol.691, pp.323-330, 2006.

G. Qian and Z. Y. Wang, Chem. Asian J, vol.5, pp.1006-1029, 2010.

E. Stankovic, S. Toma, R. Van-boxel, I. Asselberghs, and A. Persoons, J. Organomet. Chem, pp.426-434, 2001.

J. Fouassier and J. F. Rabek, Radiation Curing in Polymer Science and Technology, 1993.

S. C. Ligon, B. Husár, H. Wutzel, R. Holman, and R. Liska, Chem. Rev, vol.114, pp.557-589, 2014.

D. C. Neckers, W. Jager, . Sita-technology, and . Limited, Chemistry & Technology for UV & EB Formulation for Coatings, Inks & Paints, Photoinitiation for Polymerization: UV & EB at the Millenium, 1999.

R. S. Davidson, Exploring the Science, Technology and Applications of U.V. and E.B. Curing, Sita Tecnology Limited, 1999.

B. Wenn, M. Conradi, A. Carreiras, D. M. Haddleton, and T. Junkers, Polym. Chem, vol.5, pp.3053-3060, 2014.

P. Wu, A. K. Feldman, A. K. Nugent, C. J. Hawker, A. Scheel et al., Angew. Chem, vol.116, pp.4018-4022, 2004.

N. J. Treat, B. P. Fors, J. W. Kramer, M. Christianson, C. Chiu et al., ACS Macro Lett, vol.3, pp.580-584, 2014.

P. Garra, F. Dumur, D. Gigmes, A. Mousawi, F. Morlet-savary et al., Macromolecules, vol.50, pp.3761-3771, 2017.

P. Garra, C. Dietlin, F. Morlet-savary, F. Dumur, D. Gigmes et al., Polym. Chem, vol.8, pp.7088-7101, 2017.

P. Garra, F. Dumur, F. Morlet-savary, C. Dietlin, D. Gigmes et al., J. Polym. Sci. Part Polym. Chem, vol.55, pp.3646-3655, 2017.

P. Garra, A. Kermagoret, A. Mousawi, F. Dumur, D. Gigmes et al., Polym. Chem, vol.8, pp.4088-4097, 2017.

P. Garra, F. Dumur, F. Morlet-savary, C. Dietlin, J. P. Fouassier et al., Macromolecules, vol.49, pp.6296-6309, 2016.

P. Garra, F. Morlet-savary, C. Dietlin, J. P. Fouassier, and J. Lalevée, Macromolecules, vol.49, pp.9371-9381, 2016.

M. Bielawski, D. Aili, and B. Olofsson, J. Org. Chem, vol.73, pp.4602-4607, 2008.

J. Chen and H. Chu, J. Chem. Eng. Data, vol.52, pp.650-654, 2007.

P. Garra, M. Carré, F. Dumur, F. Morlet-savary, C. Dietlin et al., Macromolecules, vol.51, pp.679-688, 2018.

C. Dietlin, S. Schweizer, P. Xiao, J. Zhang, F. Morlet-savary et al., Polym. Chem, vol.6, pp.3895-3912, 2015.

B. Falk, S. M. Vallinas, and J. V. Crivello, J. Polym. Sci. Part Polym. Chem, vol.41, pp.579-596, 2003.

J. V. Crivello and J. H. Lam, J. Polym. Sci. Polym. Chem. Ed, vol.19, pp.539-548, 1981.

P. Garra, A. Bonardi, A. Baralle, A. Mousawi, F. Bonardi et al., J. Polym. Sci. Part Polym. Chem, vol.56, pp.889-899, 2018.

J. Foresman and E. Frish,

P. Xiao, F. Dumur, J. Zhang, J. P. Fouassier, D. Gigmes et al., Macromolecules, vol.47, pp.3837-3844, 2014.

E. F. Belogolova, T. I. , and V. F. Sidorkin, Phys. Chem. Chem. Phys, vol.17, pp.12735-12746, 2015.

R. Dieter and W. Albert, Isr. J. Chem, vol.8, pp.259-271, 1970.

A. A. Mousawi, A. Kermagoret, D. Versace, J. Toufaily, T. Hamieh et al., Polym. Chem, vol.8, pp.568-580, 2016.

S. Fery-forgues, B. Delavaux-nicot, D. Lavabre, and K. Rurack, J. Photochem. Photobiol. Chem, vol.155, pp.107-114, 2003.

M. Bouzrati-zerelli, M. Maier, C. P. Fik, C. Dietlin, F. Morlet-savary et al., Polym. Int, vol.66, pp.504-511, 2017.

B. Steyrer, B. Busetti, G. Harakály, R. Liska, and J. Stampfl, Addit. Manuf, vol.21, pp.209-214, 2018.

A. S. Sarac, Prog. Polym. Sci, vol.24, pp.1149-1204, 1999.

P. Kalenda, Eur. Polym. J, vol.31, pp.1099-1102, 1995.

P. Garra, F. Dumur, A. A. Mousawi, B. Graff, D. Gigmes et al., Polym. Chem, vol.8, pp.5884-5896, 2017.

Q. Li, C. Wang, and S. Chen, Ind. Eng. Chem. Res, vol.57, pp.3083-3090, 2018.

A. Mousawi, F. Dumur, P. Garra, J. Toufaily, T. Hamieh et al., J. Polym. Sci. Part Polym. Chem, vol.55, pp.1189-1199, 2017.

P. Garra, B. Graff, F. Morlet-savary, C. Dietlin, J. Becht et al., Macromolecules, vol.51, pp.57-70, 2018.

D. Cambié, C. Bottecchia, N. J. Straathof, V. Hessel, and T. Noël, Chem. Rev, vol.116, pp.10276-10341, 2016.

S. Shi, C. Croutxé-barghorn, and X. Allonas, Prog. Polym. Sci, vol.65, pp.1-41, 2017.

J. Lalevée and J. Fouassier, Dyes and Chomophores in Polymer Science, 2015.

K. Ueno, T. Oshikiri, Q. Sun, X. Shi, and H. Misawa, Chem. Rev, vol.118, pp.2955-2993, 2018.

M. H. Shaw, J. Twilton, and D. W. Macmillan, J. Org. Chem, vol.81, pp.6898-6926, 2016.

N. Corrigan, S. Shanmugam, J. Xu, and C. Boyer, Chem. Soc. Rev, vol.45, pp.6165-6212, 2016.

S. Dadashi-silab, S. Doran, and Y. Yagci, Chem. Rev, vol.116, pp.10212-10275, 2016.

N. Zivic, M. Bouzrati-zerelli, A. Kermagoret, F. Dumur, J. Fouassier et al., ChemCatChem, vol.8, pp.1617-1631, 2016.

J. Chen and W. R. Browne, Coord. Chem. Rev, vol.374, pp.15-35, 2018.

J. Lalevee and J. Fouassier, Photopolymerisation Initiating Systems, 2018.

T. Brömme, D. Oprych, J. Horst, P. S. Pinto, B. Strehmel et al., , vol.5, pp.69915-69924, 2015.

C. Schmitz, A. Halbhuber, D. Keil, and B. Strehmel, Prog. Org. Coat, vol.100, pp.32-46, 2016.

B. Strehmel, S. Ernst, K. Reiner, D. Keil, H. Lindauer et al., Z. Für Phys. Chem, vol.228, pp.129-153, 2014.

C. Kütahya, C. Schmitz, V. Strehmel, Y. Yagci, and B. Strehmel, Angew. Chem. Int. Ed, vol.57, pp.7898-7902, 2018.

S. Shanmugam, J. Xu, and C. Boyer, Angew. Chem. Int. Ed, vol.55, pp.1036-1040, 2016.

N. Corrigan, J. Xu, and C. Boyer, Macromolecules, vol.49, pp.3274-3285, 2016.

I. Janowska, J. Zakrzewski, K. Nakatani, J. A. Delaire, M. Palusiak et al., J. Organomet. Chem, vol.675, pp.35-41, 2003.

I. Janowska, J. Zakrzewski, K. Nakatani, M. Palusiak, M. Walak et al., J. Organomet. Chem, vol.691, pp.323-330, 2006.

G. Qian and Z. Y. Wang, Chem. Asian J, vol.5, pp.1006-1029, 2010.

E. Stankovic, S. Toma, R. Van-boxel, I. Asselberghs, and A. Persoons, J. Organomet. Chem, pp.426-434, 2001.

J. Fouassier and J. F. Rabek, Radiation Curing in Polymer Science and Technology, 1993.

S. C. Ligon, B. Husár, H. Wutzel, R. Holman, and R. Liska, Chem. Rev, vol.114, pp.557-589, 2014.

D. C. Neckers, W. Jager, . Sita-technology, and . Limited, Chemistry & Technology for UV & EB Formulation for Coatings, Inks & Paints, Photoinitiation for Polymerization: UV & EB at the Millenium, 1999.

R. S. Davidson, Exploring the Science, Technology and Applications of U.V. and E.B. Curing, Sita Tecnology Limited, 1999.

B. Wenn, M. Conradi, A. Carreiras, D. M. Haddleton, and T. Junkers, Polym. Chem, vol.5, pp.3053-3060, 2014.

P. Wu, A. K. Feldman, A. K. Nugent, C. J. Hawker, A. Scheel et al., Angew. Chem, vol.116, pp.4018-4022, 2004.

N. J. Treat, B. P. Fors, J. W. Kramer, M. Christianson, C. Chiu et al., ACS Macro Lett, vol.3, pp.580-584, 2014.

P. Garra, F. Dumur, D. Gigmes, A. Mousawi, F. Morlet-savary et al., Macromolecules, vol.50, pp.3761-3771, 2017.

P. Garra, C. Dietlin, F. Morlet-savary, F. Dumur, D. Gigmes et al., Polym. Chem, vol.8, pp.7088-7101, 2017.

P. Garra, F. Dumur, F. Morlet-savary, C. Dietlin, D. Gigmes et al., J. Polym. Sci. Part Polym. Chem, vol.55, pp.3646-3655, 2017.

P. Garra, A. Kermagoret, A. Mousawi, F. Dumur, D. Gigmes et al., Polym. Chem, vol.8, pp.4088-4097, 2017.

P. Garra, F. Dumur, F. Morlet-savary, C. Dietlin, J. P. Fouassier et al., Macromolecules, vol.49, pp.6296-6309, 2016.

P. Garra, F. Morlet-savary, C. Dietlin, J. P. Fouassier, and J. Lalevée, Macromolecules, vol.49, pp.9371-9381, 2016.

M. Bielawski, D. Aili, and B. Olofsson, J. Org. Chem, vol.73, pp.4602-4607, 2008.

J. Chen and H. Chu, J. Chem. Eng. Data, vol.52, pp.650-654, 2007.

P. Garra, M. Carré, F. Dumur, F. Morlet-savary, C. Dietlin et al., Macromolecules, vol.51, pp.679-688, 2018.

C. Dietlin, S. Schweizer, P. Xiao, J. Zhang, F. Morlet-savary et al., Polym. Chem, vol.6, pp.3895-3912, 2015.

B. Falk, S. M. Vallinas, and J. V. Crivello, J. Polym. Sci. Part Polym. Chem, vol.41, pp.579-596, 2003.

J. V. Crivello and J. H. Lam, J. Polym. Sci. Polym. Chem. Ed, vol.19, pp.539-548, 1981.

P. Garra, A. Bonardi, A. Baralle, A. Mousawi, F. Bonardi et al., J. Polym. Sci. Part Polym. Chem, vol.56, pp.889-899, 2018.

J. Foresman and E. Frish,

P. Xiao, F. Dumur, J. Zhang, J. P. Fouassier, D. Gigmes et al., Macromolecules, vol.47, pp.3837-3844, 2014.

E. F. Belogolova, T. I. , and V. F. Sidorkin, Phys. Chem. Chem. Phys, vol.17, pp.12735-12746, 2015.

R. Dieter and W. Albert, Isr. J. Chem, vol.8, pp.259-271, 1970.

A. A. Mousawi, A. Kermagoret, D. Versace, J. Toufaily, T. Hamieh et al., Polym. Chem, vol.8, pp.568-580, 2016.

S. Fery-forgues, B. Delavaux-nicot, D. Lavabre, and K. Rurack, J. Photochem. Photobiol. Chem, vol.155, pp.107-114, 2003.

M. Bouzrati-zerelli, M. Maier, C. P. Fik, C. Dietlin, F. Morlet-savary et al., Polym. Int, vol.66, pp.504-511, 2017.

B. Steyrer, B. Busetti, G. Harakály, R. Liska, and J. Stampfl, Addit. Manuf, vol.21, pp.209-214, 2018.

A. S. Sarac, Prog. Polym. Sci, vol.24, pp.1149-1204, 1999.

P. Kalenda, Eur. Polym. J, vol.31, pp.1099-1102, 1995.

P. Garra, F. Dumur, A. A. Mousawi, B. Graff, D. Gigmes et al., Polym. Chem, vol.8, pp.5884-5896, 2017.

Q. Li, C. Wang, and S. Chen, Ind. Eng. Chem. Res, vol.57, pp.3083-3090, 2018.

A. Mousawi, F. Dumur, P. Garra, J. Toufaily, T. Hamieh et al., J. Polym. Sci. Part Polym. Chem, vol.55, pp.1189-1199, 2017.

P. Garra, B. Graff, F. Morlet-savary, C. Dietlin, J. Becht et al., Macromolecules, vol.51, pp.57-70, 2018.

, To a mixture of malononitrile (0.16 g, 2.34 mmol, M = 66.06 g/mol) and

, 34 mmol, 214.00 g/mol) in absolute ethanol (50 mL) was added a few drops of piperidine

, The solvent was removed under reduced pressure. The residue was purified by column chromatography using DCM as the eluent. The different fractions were combined and the solvent removed under reduced pressure so that approximately 30 mL DCM was remaining, The solution was introduced in an oil bath preheated at 90°C. Within 10 min, the reaction was finished (TLC control)

, ,3-dihydro-1,3-dioxo-2H-inden-2-ylidene)methyl]ferrocene Fe6, Synthesis of

, To a mixture of indane-1,3-dione (0.34 g, 2.34 mmol, M = 146.14 g/mol) and ferrocene-carbaldehyde

, 34 mmol, 214.00 g/mol) in absolute ethanol (50 mL) was added a few drops of piperidine

, The solvent was removed under reduced pressure. The residue was purified by column chromatography using DCM as the eluent. The different fractions were combined and the solvent removed under reduced pressure so that approximately 30 mL DCM was remaining, The solution was introduced in an oil bath preheated at 90°C. Within 10 min, the reaction was finished (TLC control), p.7

, -oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (1.12 g, 5.79 mmol, M = 194, p.19

, 24 g, 5.79 mmol, 214.00 g/mol) in absolute ethanol (50 mL) was added a few drops of piperidine. Immediately, the color changed. The solution was introduced in an oil bath preheated at 90°C. Within 10 min, the reaction was finished (TLC control). , washed several times with pentane and

H. Nmr-;-1h and J. , 46 (s, 1H), 8.66 (d, CDCl3) ?: 4.35 (s, 5H), 5.04 (s, 2H), 5.34 (s, 2H), 7.69-7.78 (m, 2H), 7.86-7.88 (m, 1H), vol.8, p.1

, 24 g/mol, d = 0.87, 1 eq.) in THF (50 mL) at -78°C and the mixture was then warmed and stirred at room temperature for 2 h. Then, this solution was slowly transferred into the FeCl2·THF solution and stirred at room temperature for 1 h. Then, eq.) was added dropwise to pentamethylcyclopentadiene (5 mL, 31.93 mmol, 4.35 g, M = 136

H. Nmr, 69 (s, 5H), CDCl3) ?: 1.93 (s, 15H), vol.3

D. Kang and F. , Analyses were consistent with those previously reported in the literature

R. J. Ricci, K. W. White, and . Plaxco, Anal. Chem, vol.88, pp.10452-10458, 2016.

, Synthesis of 1'-formyl-1,2,3,4,5-pentamethylferrocene Fe9

, 17 g/mol) was dissolved in Nmethylformanilide (20 mL) and phosphorus oxychloride (2.6 g, 1.6 mL, 16.96 mmol, M = 153.33 g/mol, sodium chloride and extracted with ether several times. The residue was filtered on a plug of silicagel, vol.10, p.79

H. Nmr, , p.1

, CHO

C. Nmr,

. Hrms-(esi-ms)-m/z,

L. Moreau, N. Challier, F. Lalaoui, V. Mavré, B. Noël et al., Chem. Eur. J, vol.20, pp.2953-2959, 2014.

, Synthesis of 1-[1-(dicyanomethylene)-1,3-dihydro-3-oxo-2H-inden-2-ylidene]methyl]-1',2',3',4',5'-penta-methylferrocene Fe7Me

, -oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (1.12 g, 5.79 mmol, M = 194, p.19

, 18 g/mol) in absolute ethanol (50 mL) was added a few drops of piperidine. Immediately, the color changed. The solution was introduced in an oil bath preheated at 90°C. Within 10 min, the reaction was finished (TLC solid that was filtered off, washed several times with pentane and dried under reduced pressure (2.37 g, 89% yield). 1 H NMR (CDCl3) ?: 1.72 (s, 15H), 4.70 (t, 2H, J = 1.9 Hz), 5.02 (s, 2H), 7.67-7.75 (m, 2H), 7.83-7.86 (m, 1H), vol.8

. Comments, This is an interesting paper on ferrocene based redox and photoredox catalysis for radical polymerization. I recommend its publication. The authors may consider the following point