N-salicylideneaniline

Higelin D, Sixl H (1983) Spectroscopic studies of the photochromism on N-salicylideneaniline mixed crystals and glasses. Chem Phys 77 391... 

It is interesting to note that the reaction of N-salicylideneaniline, which possesses a free phenolic hydroxyl group at the ortho position in the benzylidene portion, with the acylzirconocene chloride gives the a-amino ketone in 67 % yield in the absence of any additive (Scheme 5.16) [23]. Similarly, N-(p-hydroxybenzylidene)aniline reacts with the acylzirconocene chloride to give the a-amino ketone in 58 % yield. The reaction of N-(m-hydroxyben-zylidene)aniline, however, gives the a-amino ketone in just 12 % yield. Neither N-(o-MeO-benzylidenejaniline nor N-(p-MeO-benzylidene)aniline gives an appreciable amount of product in the absence of additive. 

The majority of electro syntheses have been carried out according to route A, for example, those reported in Refs. 594 to 597. In this respect, the electrochemical syntheses (3.252) with participation of 2-tosylamino-N-salicylideneaniline 640 (X — O, Y — NTS), 1-methyl-2-aminobenzimidazole (L), cobalt, copper, and zinc (M°) were carried out in acetonitrile at room temperature (10 mA, 20 V, 4 hr) in the presence of Et4NC104 [594,595]. The structures of copper [594] and cobalt [595] complexes 804 were proved by x-ray diffraction. 

Stumpe and his co-workers [ 122-124] synthesized several SCLC methaciy-late copolymers containing the photochromic N-salicylideneaniline (NSA) chro-mophore together with several other mesogenic and nonmesogenic groups. Copolymers, 58, had from 0 to 100% of the NSA chromophore. Most of these polymers had an unspecified 5 mesophase. The NSA chromophore undergoes an excited state proton transfer (Fig. 17) to the Z-keto (often called cw-keto form)... 

Figure 17 Enol (phenol)-keto tautomerism of the N-salicylideneaniline chromophore. Photochemical processes are indicated by solid arrows, thermal processes by dotted arrows.

Amimoto, K., Kanatomi, H., Nagakari. A., Fukuda, H., Koyama, H. and Kawato, T. (2003) Deuterium isotope effect on the solid-state thermal isomerization of photo-coloured ds-keto spedes of N-salicylideneaniline. Chem. Commun., 870-871. 

Another mechanism of H-transfer in intramolecular OH- -N bond, without breaking the hydrogen bonds and without conformation change, leading to colour changes was observed in N-salicylideneanilines (4) in the function of temperature [13]. 

Ogawa, K., Kasahara, Y., Ohtani, Y. and Harada, J. (1998). Crystal structure change for the thermochromy of N-salicylideneanilines. The first observation by X-ray diffraction. J. Am. 

Investigation of the kinetics of decomposition of Ga or In azomethine complexes shows that the gallium complexes are the more stable, and that N-salicylideneaniline complexes are more stable hydrolytically than those of A-(2-hydroxy-l-naphthylidene)aniline. ... 

N-salicylideneaniline is photochromic the enol configuration can be converted to the trans-keto conformation by using light of frequency Vj, and converted back by either heat, or by light of frequency V2 here the tautomerism causes an intramolecular rotation [67]. 

Cohen, M. D. and Flavian, S., The luminescence properties of N-salicylideneaniline and related... 

Rosenfeld, T., Ottolenghi, M., and Meyer, A.Y., Photochromic anils. Structure of photoisomers and thermal relaxation process. Mol. Photochem., 5, 39, 1973 Lambi, E., Gegiou, D., and Hadjoudis, E., Thermochromism and photochromism of N-sahcyhdenebenzylamines and N-salicylidene-2-aminomethylpyridine, /. Photochem. Photohiol, A Chem., 86, 241, 1995 Goto, T. and Tashiro, Y, Photochromism of N-salicylideneaniline single crystal, /. Luminescence., 72—74, 921, 1997. 

Chloro-2-[[(2-hydroxyphenyl)methylene]amino]phenol, 9CI. 4-Chloro-2-hydroxy-N-salicylideneaniline. 2-Hydroxybenzaldehyde 4-chloro-2-hydroxy anil [31367-08-5]... 

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