High-Performance Electrochromic Devices Based on Poly[Ni(salen)]-Type Polymer Films

Abstract

We report the application of two poly [Ni(salen) was used to fabricate a solid state electrochromic device using lateral configuration with two figures of merit: a simple shape (typology 1) and a butterfly shape (typology 2); typology 1 showed the best performance with optical contrast ∆T = 88.7 % (at λ = 750 nm), colouration efficiency η = 130.4 cm 2 C -1 and charge loss of 37.0 % upon 3000 redox cycles.]

Novel hybrid based on a poly[Ni( salen )] film and WO 3 nanoparticles with electrochromic properties

“…The film O1s spectra after redox switching in LiClO4/CH3CN ( Figure S8 (b) and (b') ) exhibit the same peak at 531.1-531.6 eV (O from salen coordination sphere) [33] and one peak at 532.7-533.1 eV, assigned to occluded ClO4 -, in higher amounts, due to charge compensation processes during the redox cycles [33]. Note that it is also expected the contribution of Li + ion in the oxidation charge compensation of poly[1] [34], but its content was not considered in the XPS analysis due to the low sensitivity of XPS instrument and consequent inaccurate Li %. After redox switching in LiClO4/PC, the spectra of pristine poly [1] ( Figure S8 (c)), besides the two peaks at 531.3 eV and 532.8 eV (similarly to redox switching in CH3CN), also show an additional peak at 533.9 eV, assigned to oxygen-carbon bonds due to occluded PC [59].…”

“…The electronic band profiles with the applied potential are most readily appreciated in the differential spectra, depicted using the responses at selected potentials as reference points ( Figures S12 and S13), and by the representation of the absorbance vs. potential (Abs vs. E) profiles, at the wavelength of the detected bands (Figures 7 and 8 (a'), (b') and (c')). These representations revealed that the potential dependences of the electronic bands of the nanocomposite are similar to those of poly [1]: they show three main band profiles, characteristic of the pristine [34] and other similar poly[M(salen)] films [32,33].…”

“…The EC parameters -switching times (τ), optical contrast (∆T%), change of the optical density (∆OD) and colouration efficiency (η) -of the nanocomposite films were obtained by a double potential step method (chronoamperometry) coupled with UV-Vis spectroscopy (chronoabsorptometry). The studies were performed in 0.1 mol dm -3 LiClO4/CH3CN and LiClO4/PC solutions, focusing on the first oxidation stage (associated with the colour transition yellow ↔ green), which proved to be the most promising for pristine poly [1] [34]. In the double potential step experiment, the potential was set at the initial potential of E = 0.0 V for 50 s, then stepped to a second potential E = 0.7 V for 50 s, and finally switched back to the initial potential.…”

Water-stable [Ni(salen)]-type electrode material based on phenylazosubstituted salicylic aldehyde imine ligand

“…Polymeric nickel complexes, [Ni(Rsalen)] n , with tetradentate ligands based on the organic framework of salicylic aldehyde ethylenediimine, often referred to as salen, are widely explored as prospective materials for energy storage, 1-6 electroanalytical 7-9 and optoelectronic 10 applications. In particular, [Ni(Rsalen)] n materials bearing Br-, Cl-, Me-, 11,12 and MeO- [13][14][15] substituents in the ortho-position and alkyl 6,20,21 and Br- 19 substituents in the para-position of the phenyl ring with respect to the phenolate group have been extensively studied by other researchers. Typically, substituents in the ortho-position do not prevent the formation of polymeric material, while substituents in the para-position have been shown to prevent polymerization.…”

Aryl‐Aryl Coupling of Salicylic Aldehydes through Oxidative CH‐activation in Nickel Salen Derivatives

“…Electrochemical oxidation of nickel complexes of bis‐imines of salicylic aldehyde derivatives, referred to as NiSalens, leads to electroactive polymers which are admired for their energy storage performance, electrochromic and electrocatalytic properties. Except some specific cases, polymerization of NiSalens occurs through the formation of C−C bonds in the para ‐positions to the hydroxyl group of the phenyl rings of the ligand, which provides a new route to biphenyl compounds.…”