Spectroscopic and photophysical properties of salicylaldehyde azine (SAA) as a photochromic Schiff base suitable for heterogeneous studies

Photochromic cycle of 2′-hydroxyacetophenone azine studied by absorption and emission spectroscopy in different solvents

“…The absorption band was assigned to the ground state of enol form (conformer I) and the trends in the band position in different solvents are similar to those observed previously for SAA. 22 The absorption maximum in hydrocarbons (HEX, HEXD, and SQ) is slightly shifted to a longer wavelength (few nm) with an increasing refractive index of the solvents (370 nm in HEX and 373 nm in HEXD) This agrees with the polarizability effect observed in calculations. In polar solvents (those with significant reorientational part and, thus, Lippert-Mataga polarity function f(ε,n 2 ) = (ε -1)/(2ε + 1) -(n 2 -1)/(2n 2 + 1)) the maximum is shifted to a shorter wavelength (by about 10 nm in ACN with respect to that in HEX), and the blue shift is further increased in polar solvents of high hydrogen bond donation ability (351 nm in TFE and 349 nm in HFIP) described by parameter α (Table S1 40 ).…”

“…[15][16][17][18][19][20][21] It should be stressed that one of the main aims of the present study is to investigate the effect of the strength of intramolecular hydrogen bond on the photochromic cycle of azine derivatives of Schiff bases by comparison of the results for 2 -hydroxyacetophenone azine (APA) with those previously obtained for salicyaldehyde azine (SAA). 22 …”

p-Carboxyl-N-salicylideneanilines: Simple but efficient chromophores for one-dimensional microrods with aggregation-induced emission enhancement (AIEE) characteristics

“…It is known that salicylideneaniline derivatives show the characteristics of solid state photochromism or thermochromism [44][45][46][47][48][49]. In this study, the solid of 1-3 as powder form emitted stable fluorescence under UV 365 nm for at least 6 h, whereas they exhibited temperature-induced emission changes as shown in Fig.…”

“…In this work, we further improved salicylaldehyde azine structure and synthesized a series of p-carboxyl-N-salicylideneaniline (pCSA, compound 1-3 in Scheme 1 and Table 1) derivatives in one step, which could be easily recrystallized in organic solvent to form 1D microrods and are with AIEE characteristics. Salicyldeneanline derivatives have been extensively studied on their photochromism/thermochromism properties in solution/solid state [44][45][46][47][48][49]; however, their AIEE characteristics have not been reported. Linked by rotatable C-N single bond, pCSA exhibited typical AIEE properties with non-or weak-fluorescence in solution state but intensive emission in aggregate/solid state.…”

A photochromic thin film based on salicylideneaniline derivatives intercalated layered double hydroxide

“…Maciejewski and co-workers studied the photochromic cycle of salicylaldehyde azine in a number of different solvents and micellar systems [7], and the results showed that the lifetime of cis-keto and trans-keto tautomer was drastically affected by polarizability, viscosity and protonation of the solvents. From the viewpoint of manipulation and application of Schiff bases however, the modulation of photochromism cycle based on different solvents is not suitable and feasible.…”