Synthesis of Optically and Redox Active Polyenaminones from Diamines and α,α’-Bis[(dimethylamino)methylidene]cyclohexanediones

New oligo- and polyenaminones with Mw ~ 7–50 KDa were prepared in high yields by transaminative amino-enaminone polymerization of regioisomeric bis[(dimethylamino)methylidene]cyclohexanediones with alkylene and phenylenediamines. The polymers obtained are practically insoluble in aqueous and organic solvents and exhibit film-forming properties, UV light absorption at wavelengths below 500 nm, and redox activity. These properties indicate a promising application potential of these polymers, which could find use in optical and optoelectronic applications and in energy storage devices.


Preparation of polyenaminones 4 by acid-catalysed polymerisation of diamines 3a-f with α,α-bis[(dimethylamino)methylidene]cyclohexanediones
n the present study, we tested quinone precursors 4 that are not conjugated (lacking a double bond). However, because of their close s to ortho-and para-benzoquinones, we tested polyenaminones 4 as cathode materials in Li batteries for possible redox activity. We report sults of this study, which confirmed the feasibility of the synthesis method and showed promising redox activity of polyenaminones 4.
General Methods elting points (mp) were determined on a Kofler micro hot stage (Leica Galen III) (Leica Camera AG, Wetzlar, Germany). he NMR spectra were recorded in DMSO-d6 as deuterated solvent using Me4Si as the internal standard on a Bruker Avance III UltraSh us instrument (Bruker, Billerica, MA, USA) at 500 MHz for 1 H and at 126 MHz for 13 C nucleus, respectively. Chemical shifts (δ) are give elative to Me4Si as internal standard (δ = 0 ppm) and vicinal coupling constants (J) are given in Hertz (Hz). The following common abbr are used for description of signals in 1 H NMR spectra: singlet (s), broad singlet, (br s), and doublet (d). V spectra were recorded in MeOH using a Varian Cary Bio50 UV-Visible Spectrophotometer (Varian, Palo Alto, CA, USA). The wavelen absorption maxima (λmax) are given in nanometers (nm) and the extinction coefficients (ε) in dm 3 ·mol -1 ·cm -1 . In the present study, we tested quinone precursors 4 that are not conjugated (lacking a double bond). However, because of their close similarity to orthoand para-benzoquinones, we tested polyenaminones 4 as cathode materials in Li batteries for possible redox activity. We report here the results of this study, which confirmed the feasibility of the synthesis method and showed promising redox activity of polyenaminones 4.

General Methods
Melting points (mp) were determined on a Kofler micro hot stage (Leica Galen III) (Leica Camera AG, Wetzlar, Germany).
The NMR spectra were recorded in DMSO-d 6 as deuterated solvent using Me 4 Si as the internal standard on a Bruker Avance III UltraShield 500 plus instrument (Bruker, Billerica, MA, USA) at 500 MHz for 1 H and at 126 MHz for 13 C nucleus, respectively. Chemical shifts (δ) are given in ppm relative to Me 4 Si as internal standard (δ = 0 ppm) and vicinal coupling constants (J) are given in Hertz (Hz). The following common abbreviations are used for description of signals in 1 H NMR spectra: singlet (s), broad singlet, (br s), and doublet (d).
UV spectra were recorded in MeOH using a Varian Cary Bio50 UV-Visible Spectrophotometer (Varian, Palo Alto, CA, USA). The wavelengths of the absorption maxima (λ max ) are given in nanometers (nm) and the extinction coefficients (ε) in dm 3 ·mol −1 ·cm −1 .
Fourier-transform infrared (FT-IR) spectra were obtained on a Bruker FTIR Alpha Platinum spectrophotometer (Bruker, Billerica, MA, USA) using attenuated total reflection (ATR) sampling technique. The absorption frequencies (ν max ) in the IR spectra are given in cm −1 .
High resolution mass spectrometry (HRMS) analyses were obtained using time-offlight liquid chromatography/mass spectrometry (TOF LC/MS). An Agilent 6224 time-offlight (TOF) mass spectrometer equipped with a double orthogonal electrospray source at atmospheric pressure ionization (ESI) coupled to an Agilent 1260 high-performance liquid chromatograph (HPLC) (Agilent Technologies, Santa Clara, CA, USA) was used for recording HRMS spectra. Mobile phase composed of two solvents: A was 0.1% formic acid in Milli-Q water (Sigma-Aldrich, St. Louis, MO, USA), and B was 0.1% formic acid in acetonitrile mixed in the ratio of 1:1. Compounds were prepared by dissolving the samples in acetonitrile and 0.1-10 µL of each sample (c~1 mg mL −1 ) was injected into the liquid chromatograph-mass spectrometer (LC-MS). Flow rate was 0.4 mL/min, fragmentor voltage was 150 V, capillary voltage 4000 V, and mass range was 100-1700. The following common abbreviations are used for description of HRMS data: mass-to-charge ratio (m/z) and protonated molecular ion (MH + ).
Thermogravimetric (TG) measurements were performed on a Netzsch 449 F3 Jupiter instrument (Netzch, Selb, Germany) under a dynamic Ar (5.0) flow with a flow rate of 60 mL/min in a temperature range from 30 • C to 1200 • C. A heating rate of 10 K/min was used. About 10 mg of sample was placed in alumina (Al 2 O 3 ) crucible. Simultaneously mass spectrometry was performed on MS 403C Aëolos mass spectrometer (Netzch, Selb, Germany) with a SEM Chenneltron detector (Photonis, Paris, France) and system pressure of 2 × 10 -5 mbar. Gasses that evolved under TG heat treatment were transferred to the mass spectrometer through transfer capillary, quartz ID 75 µm (Sigma-Aldrich, St. Louis, MO, USA), which was heated up to 220 • C. The upper limit of the mass spectrometer detector was 100 AMU.
Polyenaminones microstructure characterization was performed by scanning field emission electron microscope Zeiss ULTRA plus (SEM) (Zeiss, Jena, Germany). Polyenaminones were adhered to the conductive carbon tape placed on aluminum SEM holder. Platinum-palladium, nominally 20 nm thick was evaporated on to the sample using Qurum Q150T ES turbomolecular pumped coater (AGC, Chraleroi, Belgium). SEM images were taken at 2 kV using SE2 detector at WD 4.5 mm.
Electrodes were prepared by mixing 60 mg of tested polymer material, 30 mg of carbon black (Printex XE2), and 10 mg of polytetrafluoroethylene (PTFE) (60 wt.% water dispersion) and 0.5 mL of isopropyl alcohol (IPA) (Sigma-Aldrich, St. Louis, MO, USA). All these ingredients were ball milled in 12 mL stainless steel grinding jars (10 mm Ø balls) with a planetary ball mill (Retsch PM100) at 300 rpm for 30 min in an air atmosphere (Retsch, Haan, Germany). The obtained slurry was kneaded with a mortar and pestle to obtain a compact black gum. The gum was rolled between two pieces of a nonadhesive paper with a roller to obtain an electrode film of approximately 5 cm × 5 cm size. An aluminum mesh (100 mesh size) was deposited on top of this film and the film was rolled again to glue the electrode composite and the mesh together and then dried in an air atmosphere. Afterward, electrode discs with a diameter of 1.2 cm were cut and pressed with a load of 1 ton and further dried at 60 • C in a vacuum for 1 day. The average loading on the electrode was around 2.5 mg of active material per cm 2 . Battery cells were assembled in an argon-filled glovebox (water and oxygen levels <1 ppm). Swagelok-type battery cells were assembled using the above-mentioned electrodes, a 13 mm glass fiber separator (Whatman GF/A) (Whatman plc, Maidstone, Kent, UK), and freshly rolled lithium (12 mm diameter) (Sigma-Aldrich, St. Louis, MO, USA). 1 M Bis(trifluoromethane)sulfonimide lithium salt in a mixture of dry 1,3-dioxolane/dimethoxyethane was used an electrolyte (1 M LiTFSI/DOL+DME) (Sigma-Aldrich, St. Louis, MO, USA). A potentiostat/galvanostat VMP3 (Bio-Logic, Seyssinet-Pariset, France) was used at room temperature (25 • C) to perform the electrochemical measurements. Batteries were galvanostatically cycled between 1.5-3.5 V vs. Li/Li + at a current density of 50 mA/g according to mass of tested polymer.

General Procedure for the Synthesis of Compounds 2a and 2b
A mixture of cyclohexanedione 1a,b (1.121 g, 10 mmol), DMFDMA (3.0 mL, 22 mmol), and anhydrous PhMe (10 mL) was heated under reflux for 5 h. The reaction mixture was cooled to 20 • C, the precipitate was collected by filtration, and washed with toluene (2 × 5 mL) to give 2a,b. The following compounds were prepared in this manner:

General Procedure for the Synthesis of Compounds 4aa-4af and 4ba-4bf
A mixture of compound 2 (222 mg, 1 mmol), diamine dihydrochloride 3 (1 mmol), and methanol (10 mL) was stirred at 20 • C for 72 h. The precipitate was collected by filtration, and washed with MeOH (2 mL) to give 4. The following compounds were prepared in this manner:

Synthesis
The starting bis-enaminones 2a and 2b were prepared in moderate yields of about 50% by heating the corresponding diketones 1a and 1b with 1.2 equiv. DMFDMA in toluene for 5 h. The moderate yields of enaminones 2 were due to partial conversion that could not be improved by longer reaction time and higher reaction temperature (Scheme 1). Bisenaminones 2a and 2b were then treated with equimolar amounts of aliphatic (3a-c) and aromatic diamines (3d-f) dihydrochlorides in methanol at room temperature for 72 h and the precipitated products 4 were obtained by filtration in 10-99% yields (Scheme 1, Table 1).

Synthesis
The starting bis-enaminones 2a and 2b were prepared in moderate yields of about 50% by heating the corresponding diketones 1a with 1.2 equiv. DMFDMA in toluene for 5 h. The moderate yields of enaminones 2 were due to partial conversion that could not be impro longer reaction time and higher reaction temperature (Scheme 1). Bis-enaminones 2a and 2b were then treated with equimolar amounts of a (3a-c) and aromatic diamines (3d-f) dihydrochlorides in methanol at room temperature for 72 h and the precipitated products 4 were o by filtration in 10-99% yields (Scheme 1, Table 1).  According to previously reported closely related transformations, reactions of bisenaminones 2 and diamines 3 most probably proceed as a step-growth polymerisation, where consecutive intermolecular transaminations give polymeric products 4 [19,20,29].  Table 1. Experimental data for compounds 4.
FTIR spectra of compounds 4 show absorption bands at around 1600 cm −1 , which are characteristic for the C=O group of a conjugated ketone. Absorption bands around

Characterisation
The monomers 2a and 2b were characterised by spectroscopic me C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised b matography (SEC), thermogravimetric analysis-mass spectromety (TG FTIR spectra of compounds 4 show absorption bands at around 1 Absorption bands around 2900 cm -1 in the spectra of the enaminones 2 Broad absorption bands around 3000 cm -1 in the spectra of compound in the solid state. For details see the Supplementary Material.
Molar mass characteristics were determined by relative SEC in T Table 2). Sample 4aa (▬) shows molar mass averages typical for oligom 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for hand, compounds 4ba (▬) and 4bc (▬) show much higher molar ma 5.29, respectively (Figure 2, Table 2, entries 3 and 4). These results su bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly analogue 1a (Table 2; entry 1).  UV-vis spectra of compounds 4 were measured in MeOH at 250details see the Supplementary Material), which was consistent with t compounds 4 indicated interesting UV light shielding properties that Compounds 4 did not exhibit melting points between 20 and 300 sition above 200 °C. This was not really surprising, as similar absence The representative polymers 4aa ( Figure 3A) and 4ba ( Figure 3B) were Polyenaminones 4aa and 4ba were pyrolysed in Ar atmosphere in ord applications. Thermogravimetric curves ( Figure 3A,B) revealed that bo start to decompose at temperature above 200 °C, which exhibit high st operating temperature region for Li-ion batteries is between −20 °C a and 72.3 wt.% for 4aa and 4ba, respectively. Further, closer inspectio polyenaminones happens in at least 4 different temperature regions. methyl (CH3 + ), water and CO2 signals. In the first region (temperature as decomposition products. In the second region (temperature range b water are released. Third region (temperature range between 450 °C between 950 °C and 1200 °C) only CO2 is evolving. Regions I and II regions III and IV are related to decomposition of resilient functiona pyrolyzed polyenaminones can have potential use in electrocatalysis s ) was almost insoluble in TEAN/HFIP, therefore the results for this sample are not representative (Figure 2;

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NMR, 13 C NMR, C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscopic methods ( 1 H matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and scanning electr FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , which are characte Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, were in line with t Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in agreement with in the solid state. For details see the Supplementary Material.
Molar mass characteristics were determined by relative SEC in TEAN/HFIP for the represen Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species with the respec 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample are not represe hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages typical for poly 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results support a step-growth polyme bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly higher degree of polymeris analogue 1a (Table 2; entry 1).  UV-vis spectra of compounds 4 were measured in MeOH at 250-800 nm and showed absorpt details see the Supplementary Material), which was consistent with the data for closely related p compounds 4 indicated interesting UV light shielding properties that might find use in various op Compounds 4 did not exhibit melting points between 20 and 300 °C. They were thermally sta sition above 200 °C. This was not really surprising, as similar absence of melting points is also ch The representative polymers 4aa ( Figure 3A) and 4ba ( Figure 3B) were characterised for thermal p Polyenaminones 4aa and 4ba were pyrolysed in Ar atmosphere in order to probe their thermal st applications. Thermogravimetric curves ( Figure 3A,B) revealed that both of polyenaminones beha start to decompose at temperature above 200 °C, which exhibit high stability of polyenaminones fo operating temperature region for Li-ion batteries is between −20 °C and +60 °C. Total weight loss and 72.3 wt.% for 4aa and 4ba, respectively. Further, closer inspection of both thermograms (Fi polyenaminones happens in at least 4 different temperature regions. Regions were defined arbit methyl (CH3 + ), water and CO2 signals. In the first region (temperature range between 200 °C and 30 as decomposition products. In the second region (temperature range between 300 °C and 400 °C), water are released. Third region (temperature range between 450 °C and 700 °C) represents ev between 950 °C and 1200 °C) only CO2 is evolving. Regions I and II are related to thermal deg regions III and IV are related to decomposition of resilient functional groups and graphitization pyrolyzed polyenaminones can have potential use in electrocatalysis since they are expected to ha ) and 4bc (

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NMR, 13 C NMR, C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscopic methods ( 1 H matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and scanning electr FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , which are characte Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, were in line with t Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in agreement with in the solid state. For details see the Supplementary Material.
Molar mass characteristics were determined by relative SEC in TEAN/HFIP for the represen Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species with the respec 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample are not represe hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages typical for poly 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results support a step-growth polym bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly higher degree of polymeris analogue 1a (Table 2; entry 1).  UV-vis spectra of compounds 4 were measured in MeOH at 250-800 nm and showed absorpt details see the Supplementary Material), which was consistent with the data for closely related p compounds 4 indicated interesting UV light shielding properties that might find use in various op Compounds 4 did not exhibit melting points between 20 and 300 °C. They were thermally sta sition above 200 °C. This was not really surprising, as similar absence of melting points is also ch The representative polymers 4aa ( Figure 3A) and 4ba ( Figure 3B) were characterised for thermal p Polyenaminones 4aa and 4ba were pyrolysed in Ar atmosphere in order to probe their thermal st applications. Thermogravimetric curves ( Figure 3A,B) revealed that both of polyenaminones beha start to decompose at temperature above 200 °C, which exhibit high stability of polyenaminones fo operating temperature region for Li-ion batteries is between −20 °C and +60 °C. Total weight loss and 72.3 wt.% for 4aa and 4ba, respectively. Further, closer inspection of both thermograms (Fi polyenaminones happens in at least 4 different temperature regions. Regions were defined arbit methyl (CH3 + ), water and CO2 signals. In the first region (temperature range between 200 °C and 3 as decomposition products. In the second region (temperature range between 300 °C and 400 °C), water are released. Third region (temperature range between 450 °C and 700 °C) represents ev between 950 °C and 1200 °C) only CO2 is evolving. Regions I and II are related to thermal deg regions III and IV are related to decomposition of resilient functional groups and graphitization pyrolyzed polyenaminones can have potential use in electrocatalysis since they are expected to ha ) show much higher molar mass averages typical for polymeric species with dipersity values of 1.91 and 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results support a step-growth polymerization mechanism showing 1,4-disubstituted bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly higher degree of polymerisation than the 1,2-disubstituted bis-enaminone analogue 1a ( Table 2; entry 1).
FTIR spectra of compounds 4 show absorption bands at aro Absorption bands around 2900 cm -1 in the spectra of the enamin Broad absorption bands around 3000 cm -1 in the spectra of com in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SE Table 2). Sample 4aa (▬) shows molar mass averages typical for 4af (▬) was almost insoluble in TEAN/HFIP, therefore the resu hand, compounds 4ba (▬) and 4bc (▬) show much higher mo 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These resu bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes signific analogue 1a (Table 2; entry 1).  UV-vis spectra of compounds 4 were measured in MeOH a details see the Supplementary Material), which was consistent compounds 4 indicated interesting UV light shielding propertie  UV-vis spectra of compounds 4 were measured in MeOH at 250-800 nm and showed absorption maxima at around 300, 350, and 450 nm (for details see the Supplementary Material), which was consistent with the data for closely related polymers [19,20]. These UV-vis spectral data of compounds 4 indicated interesting UV light shielding properties that might find use in various optical applications.
Compounds 4 did not exhibit melting points between 20 and 300 • C. They were thermally stable up to 200 • C and then underwent decomposition above 200 • C. This was not really surprising, as similar absence of melting points is also characteristic for related polyenaminones [19,20]. The representative polymers 4aa ( Figure 3A) and 4ba ( Figure 3B) were characterised for thermal properties using thermogravimetric analysis [35]. Polyenaminones 4aa and 4ba were pyrolysed in Ar atmosphere in order to probe their thermal stability in inert environments relevant to battery applications. Thermogravimetric curves ( Figure 3A,B) revealed that both of polyenaminones behave similarly under elevated temperatures. They start to decompose at temperature above 200 • C, which exhibit high stability of polyenaminones for potential battery applications. The acceptable operating temperature region for Li-ion batteries is between −20 • C and +60 • C. Total weight loss over the entire temperature range is 68.2 wt.% and 72.3 wt.% for 4aa and 4ba, respectively. Further, closer inspection of both thermograms ( Figure 3A,B) revealed that the decomposition of polyenaminones happens in at least 4 different temperature regions. Regions were defined arbitrary according to m/z fragments that represent methyl (CH 3 + ), water and CO 2 signals. In the first region (temperature range between 200 • C and 300 • C), evolution of all three species are released as decomposition products. In the second region (temperature range between 300 • C and 400 • C), where the highest weight loss occurs, CH 3 + and water are released. Third region (temperature range between 450 • C and 700 • C) represents evolution of CH 3 + and fourth (temperature range between 950 • C and 1200 • C) only CO 2 is evolving. Regions I and II are related to thermal degradation (pyrolysis) of polyenaminones, while regions III and IV are related to decomposition of resilient functional groups and graphitization of the carbon residue. We also speculate that pyrolyzed polyenaminones can have potential use in electrocatalysis since they are expected to have nitrogen doped in graphitized structure.
Polymers 4aa and 4ba were morphologically analysed using SEM (Figure 4) [1][2][3][4]36,37]. For both polymers, SEM images were taken at the same magnification (2 × 10 4 ) and compared. The morphological analysis revealed that both polymers are agglomerates consisting of smaller particles with irregular shapes and a broad particle size distribution. Polymer 4aa ( Figure 4A) consists of agglomerated particles with a diameter up to 3 µm, while the particles of polymer 4ba ( Figure 4B) are smaller and have a diameter up to 0.5 µm. Moreover, the morphology of the particles of both polymers exhibits a porous structure, which is of great importance if these materials are to be used in energy storage devices such as batteries. High porosity and the associated high specific surface area are important for the accessibility of the battery electrolyte and thus for achieving high current densities. This could have a major impact on the lifetime and operation of the batteries.
Redox activity of compounds 4ae, 4af, and 4be was investigated in Li-battery, where polymers were used as a cathode materials and Li metal as anode. From galvanostatic tests capacity vs. cycle number was extracted, as shown in Figure 5A. The compound 4ae exhibited maximal 98 mAh/g capacity which quickly dropped but then stabilized at 68 mAh/g after 20 cycles. This capacity drop can be attributed to limited solubility of 4ae polymer inside ethereal electrolyte and/or side reactions in initial cycles, which are both known phenomena from the literature [38]. Material 4ae showed low Coulombic efficiency <95% in first 10 cycles, which could further indicate side electrochemical reactions, but then it stabilized at around 97%. On the other hand, compounds 4af and 4be showed low capacity, which is probably connected only to carbon black pseudocapacity and not to real redox activity of the polymers ( Figure 5A). The galvanostatic curves of compounds 4ae, 4af, and 4be are presented in Figure 5B. The curves did not exhibit any discernible plateaus. Nevertheless, the slope of 4ae ( Polymers 2022, 14, x FOR PEER REVIEW

Characterisation
The monomers 2a and 2b were characterised by spectroscopic met C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by matography (SEC), thermogravimetric analysis-mass spectromety (TGA FTIR spectra of compounds 4 show absorption bands at around 16 Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a Broad absorption bands around 3000 cm -1 in the spectra of compounds in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TE Table 2). Sample 4aa (▬) shows molar mass averages typical for oligom 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for t hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mas 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results sup bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly h analogue 1a (Table 2; entry 1).
) changes, which can indicate redox activity. Polymers 4aa and 4ba were morphologically analysed using SEM (Figure 4) [1][2][3][4]36,37]. For both polymers, SEM same magnification (2 × 10 4 ) and compared. The morphological analysis revealed that both polymers are agglomerates ticles with irregular shapes and a broad particle size distribution. Polymer 4aa ( Figure 4A) consists of agglomerated pa to 3 μm, while the particles of polymer 4ba ( Figure 4B) are smaller and have a diameter up to 0.5 μm. Moreover, the m of both polymers exhibits a porous structure, which is of great importance if these materials are to be used in energ batteries. High porosity and the associated high specific surface area are important for the accessibility of the batter Polymers 4aa and 4ba were morphologically analysed using SEM (Figure 4) [1][2][3][4]36,37]. For both polymers, SEM image same magnification (2 × 10 4 ) and compared. The morphological analysis revealed that both polymers are agglomerates consis ticles with irregular shapes and a broad particle size distribution. Polymer 4aa ( Figure 4A) consists of agglomerated particles to 3 μm, while the particles of polymer 4ba ( Figure 4B) are smaller and have a diameter up to 0.5 μm. Moreover, the morphol of both polymers exhibits a porous structure, which is of great importance if these materials are to be used in energy stora batteries. High porosity and the associated high specific surface area are important for the accessibility of the battery elect achieving high current densities. This could have a major impact on the lifetime and operation of the batteries. Redox activity of compounds 4ae, 4af, and 4be was investigated in Li-battery, where polymers were used as a cathode ma as anode. From galvanostatic tests capacity vs. cycle number was extracted, as shown in Figure 5A. The compound 4ae ex mAh/g capacity which quickly dropped but then stabilized at 68 mAh/g after 20 cycles. This capacity drop can be attributed t of 4ae polymer inside ethereal electrolyte and/or side reactions in initial cycles, which are both known phenomena from the liter 4ae showed low Coulombic efficiency <95% in first 10 cycles, which could further indicate side electrochemical reactions, but around 97%. On the other hand, compounds 4af and 4be showed low capacity, which is probably connected only to carbon bl and not to real redox activity of the polymers ( Figure 5A). The galvanostatic curves of compounds 4ae, 4af, and 4be are pres The curves did not exhibit any discernible plateaus. Nevertheless, the slope of 4ae (▬) changes, which can indicate redox acti To study electroactivity more in detail, dQ/dE vs. potential E is presented in Figure 6A. In the curve of co Oxidation) and 1.8 V vs. Li/Li + (Reduction) diminish after few cycles and are probably linked to irreversible reacti he other two compounds exhibited almost flat curves (▬, ▬), indicating pseudocapacity without redox activity ocapacity is high surface area of electron-conductive carbon black additive, which is needed for electrode prepara urve of compound 4ae (▬) exhibited two oxidation peaks at 2.32 V and 2.58 V vs. Li and one reduction peak at otentials are in agreement with other carbonyl materials [39], which generally show voltages of 2.0-3.0 V vs. Li/L

Characterisation
The monomers 2a and 2b w C, H, and N. The products 4aamatography (SEC), thermogravi FTIR spectra of compounds Absorption bands around 2900 c Broad absorption bands around in the solid state. For details see Molar mass characteristics Table 2). Sample 4aa (▬) shows 4af (▬) was almost insoluble in hand, compounds 4ba (▬) and 5.29, respectively (Figure 2, Tab bis-enaminone 1b (

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NMR, 13 C NMR, FTIR, and HRMS) an C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscopic methods ( 1 H NMR, FTIR, and UV matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and scanning electron microscopy (SEM FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , which are characteristic for the C=O gro Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, were in line with typical C-H and N-H Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in agreement with N-H···O=C hydrogen in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEAN/HFIP for the representative samples 4aa, 4 Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species with the respective dispersity of 1.4 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample are not representative (Figure 2; Tab hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages typical for polymeric species with d 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results support a step-growth polymerization mechanism bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly higher degree of polymerisation than the 1,2-di analogue 1a (Table 2; entry 1).
To study electroactivity more in detail, dQ/dE vs. potential E is presented in Figure 6A. In the curve of compound 4ae ( Polymers 2022, 14, x FOR PEER REVIEW

Characterisation
The monomers 2a and 2b were characterised by spectroscopic meth C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by matography (SEC), thermogravimetric analysis-mass spectromety (TGA FTIR spectra of compounds 4 show absorption bands at around 160 Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEA Table 2). Sample 4aa (▬) shows molar mass averages typical for oligome 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for th hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results supp bis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly hig analogue 1a (Table 2; entry 1).
), indicating pseudocapacity without redox activity ( Figure 6A). The origin of pseudocapacity is high surface area of electron-conductive carbon black additive, which is needed for electrode preparation. After the 10th cycle, dQ/dE curve of compound 4ae ( Polymers 2022, 14, x FOR PEER REVIEW
) exhibited two oxidation peaks at 2.32 V and 2.58 V vs. Li and one reduction peak at 2.32 V vs. Li ( Figure 6B). These potentials are in agreement with other carbonyl materials [39], which generally show voltages of 2.0-3.0 V vs. Li/Li + .
(Oxidation) and 1.8 V vs. Li/Li + (Reduction) diminish after few cycles and are pro The other two compounds exhibited almost flat curves (▬, ▬), indicating pseud docapacity is high surface area of electron-conductive carbon black additive, whi curve of compound 4ae (▬) exhibited two oxidation peaks at 2.32 V and 2.58 V potentials are in agreement with other carbonyl materials [39], which generally  Figure 7. Theoretical capacity of 4ae is 2 Equation (1). The maximum obtainable capacity was 98 mAh/g, which is around tion are common [39,41,42] in Li-organic batteries and are usually due to limited isolators). Capacity could be further improved by preparation of smaller particl electrode and electrolyte engineering [47] but is not main topic of this article. An similar to 4ae with the same 1,2-diketone redox centre, doesn't show any redox a transport of 4af material: bigger particles, lower porosity, more rigid structure o different 1,4-diketone centre is hindered due to the same reason.

Characterisation
The monomers 2a and 2b were characterised by spectros C, H, and N. The products 4aa-4af, and 4ba-4bf were charac matography (SEC), thermogravimetric analysis-mass spectrom FTIR spectra of compounds 4 show absorption bands at a Absorption bands around 2900 cm -1 in the spectra of the enam Broad absorption bands around 3000 cm -1 in the spectra of co in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative Table 2). Sample 4aa (▬) shows molar mass averages typical f 4af (▬) was almost insoluble in TEAN/HFIP, therefore the re hand, compounds 4ba (▬) and 4bc (▬) show much higher m 5.29, respectively (Figure 2, Table 2, entries 3 and 4). These re bis-enaminone 1b (Table 2; entries 3 and 4) undergoes signi analogue 1a (Table 2; entry 1).

Characterisation
The monomers 2a and 2b were characterised by spectroscopic meth C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by s matography (SEC), thermogravimetric analysis-mass spectromety (TGA-FTIR spectra of compounds 4 show absorption bands at around 1600 Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a a Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEA Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomer 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for thi hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass 5.29, respectively ( Figure 2, Table 2, entries 3 and 4). These results supp bis-enaminone 1b (Table 2; entries 3 and 4) undergoes significantly hig analogue 1a (Table 2; entry 1).

Characterisation
The monomers 2a and 2b were characterised by spec C, H, and N. The products 4aa-4af, and 4ba-4bf were cha matography (SEC), thermogravimetric analysis-mass spec FTIR spectra of compounds 4 show absorption bands Absorption bands around 2900 cm -1 in the spectra of the e Broad absorption bands around 3000 cm -1 in the spectra o in the solid state. For details see the Supplementary Mate Molar mass characteristics were determined by relat Table 2). Sample 4aa (▬) shows molar mass averages typi 4af (▬) was almost insoluble in TEAN/HFIP, therefore th hand, compounds 4ba (▬) and 4bc (▬) show much high 5.29, respectively (Figure 2, Table 2, entries 3 and 4). The bis-enaminone 1b (Table 2; entries 3 and 4) undergoes s analogue 1a (Table 2; entry 1).

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NMR, C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscopic m matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and scan FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , which a Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, were in Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in agree in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEAN/HFIP for th Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species with 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample are n hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages typi 5.29, respectively (Figure 2, Table 2, entries 3 and 4). These results support a step-grow bis-enaminone 1b (Table 2; entries 3 and 4) undergoes significantly higher degree of analogue 1a (Table 2; entry 1).

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NMR, 13 C NMR, F C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscopic methods ( 1 H matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and scanning electr FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , which are characte Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, were in line with t Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in agreement with in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEAN/HFIP for the represen Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species with the respec 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample are not represen hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages typical for poly 5.29, respectively (Figure 2, Table 2, entries 3 and 4). These results support a step-growth polyme bis-enaminone 1b (Table 2; entries 3 and 4) undergoes significantly higher degree of polymeris analogue 1a (Table 2; entry 1).

Characterisation
The monomers 2a and 2b were characterised by spectroscopic methods ( 1 H NM C, H, and N. The products 4aa-4af, and 4ba-4bf were characterised by spectroscop matography (SEC), thermogravimetric analysis-mass spectromety (TGA-MS), and FTIR spectra of compounds 4 show absorption bands at around 1600 cm -1 , whi Absorption bands around 2900 cm -1 in the spectra of the enaminones 2a and 2b, we Broad absorption bands around 3000 cm -1 in the spectra of compounds 4 were in a in the solid state. For details see the Supplementary Material. Molar mass characteristics were determined by relative SEC in TEAN/HFIP f Table 2). Sample 4aa (▬) shows molar mass averages typical for oligomeric species 4af (▬) was almost insoluble in TEAN/HFIP, therefore the results for this sample a hand, compounds 4ba (▬) and 4bc (▬) show much higher molar mass averages t 5.29, respectively (Figure 2, Table 2, entries 3 and 4). These results support a stepbis-enaminone 1b ( Table 2; entries 3 and 4) undergoes significantly higher degre analogue 1a (Table 2; entry 1).  Although compound 4ae doesn't contain real ortho-quinone group, it can be still regarded as 1,2-diketone and can act as a redox centre [40]. Proposed redox reaction is presented in Figure 7. Theoretical capacity of 4ae is 223 mAh/g, according to proposed two electron redox reaction and Equation (1). The maximum obtainable capacity was 98 mAh/g, which is around 44% of the theoretical value. Such low values of material utilization are common [39,41,42] in Li-organic batteries and are usually due to limited ionic and electronic transport inside organic materials (electrical isolators). Capacity could be further improved by preparation of smaller particles [43,44], composites with electronconductive additives [45,46], electrode and electrolyte engineering [47] but is not main topic of this article. Another interesting observation is that compound 4af, which is very similar to 4ae with the same 1,2-diketone redox centre, doesn't show any redox activity. The reason could be in a much worse ionic and electronic transport of 4af material: bigger particles, lower porosity, more rigid structure of the polymer, etc. It is also possible that redox activity of 4be with different 1,4-diketone centre is hindered due to the same reason. isolators). Capacity could be further improved by preparation of smaller particles [43,44], composites with electron-conducti electrode and electrolyte engineering [47] but is not main topic of this article. Another interesting observation is that compoun similar to 4ae with the same 1,2-diketone redox centre, doesn't show any redox activity. The reason could be in a much worse transport of 4af material: bigger particles, lower porosity, more rigid structure of the polymer, etc. It is also possible that redox different 1,4-diketone centre is hindered due to the same reason.

Conclusions
Acid-catalysed transamination of bis-enamino ketones 2a and 2b with aliphatic (3a-c) and aromatic (3d-f) diamines gave polyenaminones 4aa-4af and 4ba-4bf in 10-100% yields with molar mass averages from around 7 to 50 kg/mol. Polyenaminones 4aa-4af and 4ba-4bf are practically insoluble in conventional organic solvents. Monomer building blocks 2a,b and 3a-f are accessible from biomass-derived precursors, such as cyclohexanone, succinic acid, and alkanediols. Compounds of group 4 strongly absorb UV light at wavelengths below 500 nm, indicating their promising potential in optical and optoelectronic applications. Preliminary experiments showed that some of these polymers are redox active molecules, which could be used in energy storage devices. However, further investigation needs to be done with polyenaminones bearing quinone and hydroquinone redox centers to fully exploit their theoretical capacities.