Synthesis of Some New Substituted Photochromic N,N′‐Bis(spiro[1‐benzopyran‐2,2′‐indolyl])diazacrown Systems with Substituent Control over Ion Chelation

Abstract

The reversible photochemical ion chelation of the newly synthesised substituted N, )diazacrown systems 15a-c and the subsequent molecular electronic control of this process using appropriately placed substituent groups on the spiro-benzopyran skeleton is reported. The principle of molecular electronic control of ion chelation is demonstrated by comparing the behaviour of the newly synthesised nitro-substituted and pyrido-annulated spiro-benzopyran system 9b with that of the unsubstituted

Three-component spiropyran synthesis via tandem alkylation-condensation

“…Firstly, we have focussed on incorporating substituents in positions that are known to influence spiro-mero equilibration, hence giving control and tunability to spiropyran products in this fundamental property. This is achieved either electronically, through stabilisation/destabilisation of the merocyanine phenoxide and iminium moieties 34,35 -hence we have demonstrated control over all benzenoid chromene positions (i.e. 6q-6y) and the indole 5-position (6e,f) respectively ‡ -or by exerting steric control through incorporation of large substituents in the indole 3-position (e.g.…”

Photoreversible Zn2+ Ion Transportation Across an Interface Using Ion‐Chelating Substituted Photochromic 3,3′‐Indolospirobenzopyrans: Steric and Electronic Controlling Effects

“…We previously reported that the spirobenzopyran↔merocyanine equilibrium position in crown‐containing systems, under photolysis, could be influenced by the use of appropriately placed “electronically‐controlling” substituents; specifically in the 5‐position of the indole ring 8a,8b…”

Photochromic Cotton Fabric Prepared by Spiropyran-ternimated Water Polyurethane Coating

“…The spiropyrans is generally prepared by a condensation reaction between indolone derivative and nitroso salicylaldehyde. 5nitrosalicylaldehyde (1) was synthesis via the reaction between 4-nitrophenol and formaldehyde [25]. 2,3,3trimethyl-3-indole and 3-bromoethanol are subjected to an alkylation reaction to obtain porphyrin (2) finally, which is then treated with potassium hydroxide.…”