1,1'-Binaphtho(aza)crowns Carrying Photochromic Signalling Unit, I: Synthesis, Characterization and Cation Recognition Properties

Abstract

S)-1,1'-Binaphtho(monoaza)crown-5,-6 and-7 ionophores carrying photochromic indolospirobenzopyran (SP), naphthoxazine (NO) and naphthopyran (NP) signalling groups were synthesized and their cationinduced isomerisation to the colored merocyanine or quinone forms was studied by UV/Vis spectroscopy in the presence of alkali and alkaline earth metal ions. Under dark conditions the equilibrium of SP and NO dyes were remarkably shifted to the colored form by cations of high positive charge density (Li 1 and alkaline earth metal ions). The same effects were observed with crowned NPs after UV irradiation. The stability of some merocyanine-cation complexes were evaluated by calculating the kinetic parameters of the coloration process.

Metal complexes of the merocyanine form of nitrobenzospyran: Structure, optical spectra, stability

“…SP-1 is an important model of spiropyran type photochromic compounds [10][11][12][13][14][15][16][17]. Various derivatives of SP-1 have been synthesized that form complexes of high stability with metal ions, like the 'bidentate' ligands (they bridge the metal ion by the phenolic oxygen of their MC form and an additional receptive site) [18,19], the multidentate ligands [20,21] and the spiropyrans with attached macrocyclic coordination spheres [22][23][24][25][26]. Görner and Chibisov studying the coordination of metal ions by 'bidentate' spiropyrans in solution, found that the parent compound MC-1 behaves as a 'monodentate' ligand and -like its bidentate derivatives -forms also 1:1 complexes with transition metals [27,28].…”

BINOL-based azacrown ether catalyzed enantioselective Michael addition: asymmetric synthesis of α-aminophosphonates

“…Beside the parent 1,1 0 -bi-2-naphtho(17-monoazacrown-5)ether, 7 only a few N-substituted fluorescent and photochromic derivatives have been described and their optical responses toward metal ions studied. 7b, 8 It should be noted that none of these molecules have been used as chiral catalysts for asymmetric reactions promoted by alkali bases.…”