Synthesis of Novel Iono‐ and Photochromic Spiropyrans Derived from 6,7‐Dihydroxy‐8‐Formyl‐4‐Methyl‐2H‐Chromene‐2‐One

Abstract

Novel photochromic spiropyrans (SPPs) containing6′-hydroxy group were synthesized and their spectral properties as well as abilities for complexation with metal ions studied. In solutions they exist as equilibrium mixture of spirocyclic (A) and merocyanine (B) isomers. The largest content of merocyanine form was found for the derivative with an electron-donating methyl group in position 5 of hetaryl fragment. The irradiation of SPPs in acetonitrile shifts the equilibrium to the B form. Similar effect causes the addition of metal cations due to formation of colored complexes with merocyanine isomers.

Molecular switches as photocontrollable “smart” receptors

“…Chelation of Mg 2+ , Zn 2+ , Ni 2+ , Cu 2+ , Hg 2+ , and Pd 2+ by spiropyrans 52-57 (Scheme 31) has been reported. 81 The hydroxy group adjacent to the benzopyran oxygen is a common motif present in all compounds belonging to this series. Once the spiropyrans isomerise to their open form, the hydroxy group is accessible for coordination of a metal along with the vicinal phenolate.…”

Photo- and ionochromic indoline spiropyrans based on 7,8-dihydroxy-4-methyl-2-oxo-2H-chromene-6-carbaldehyde

“…Complexes like IIC were reported by us previously [12]. The presence of OH group therein follows from insignificant change of the corresponding absorption band in the IR spectra.…”

Synthesis, photo- and ionochromic properties of indolyl(thienyl)maleimides with phenanthroline receptor

“…Photochromic compounds that switch between isomeric states under irradiation with light of a certain wavelength are extensively studied. [1][2][3][4][5][6][7] Spirocyclic compounds, [8][9][10] fulgides and fulgimides, [11][12][13] dihetarylethenes, 14,15 photochromic heterocyclic ketoenamines 16,17 and norbornadienes 18,19 are of particular interest due to their potential industrial applications, including design of materials for molecular electronics, rewritable optical memory, photo optical commutation, organic displays, photo-pharmacology, biological data visualization, chemo-and biosensors. Chemical modification of photochromic molecules with ionochromic substituents opens new possibilities to create of photo controllable chemosensors in which the coordination and release of ions is modulated with light of different wavelengths.…”