Liposomal membranes. 13. Transport of an amino acid across liposomal bilayers as mediated by a photoresponsive carrier

Photocontrollable Cation Extraction with Crowned Oligo(spirobenzopyran)s

“…[1][2][3][4] Spirobenzopyrans, typical photochromic compounds, isomerize from their electrically neutral spirobenzopyran forms to the corresponding zwitterionic merocyanine form, which has a maximum absorption wavelength around 550 nm, by UV-light irradiation, and vice versa by visible-light irradiation and/or heat. [5][6][7][8][9] Since spirobenzopyrans change not only their conformation but also their electrical properties by photoirradiation, the interaction between the photoionized molecule and a cation may be affected considerably.We had already synthesized spirobenzopyran derivatives bearing a crown ether moiety, which we call crowned spirobenzopyrans [crowned mono(spirobenzopyran)].We studied their metal-ion complexing abilities, photochromism, and applications to photocontrollable devices. [10][11][12][13][14][15] Crowned spirobenzopyrans form complexes with metal ions and simultaneously isomerize from their spirobenzopyran form to the corresponding merocyanine form under dark condition, due to the ionic interaction between the phenolate anion of the merocyanine form and a metal ion complexed by their crown ether moiety (Scheme 1).…”

“…[1][2][3][4] Spirobenzopyrans, typical photochromic compounds, isomerize from their electrically neutral spirobenzopyran forms to the corresponding zwitterionic merocyanine form, which has a maximum absorption wavelength around 550 nm, by UV-light irradiation, and vice versa by visible-light irradiation and/or heat. [5][6][7][8][9] Since spirobenzopyrans change not only their conformation but also their electrical properties by photoirradiation, the interaction between the photoionized molecule and a cation may be affected considerably.…”

Evaluation of photoinduced changes in stability constants for metal-ion complexes of crowned spirobenzopyran derivatives by electrospray ionization mass spectrometry

“…Previously, we synthesized spirobenzopyran derivatives bearing a crown ether moiety, which we called crowned spirobenzopyran, and studied their metal-ion complexing abilities, photochromism, and applications for devices [13][14][15][16][17][18][19][20][21][22]. Spirobenzopyran derivatives, which are typical photochromic compounds, are isomerized from their spirobenzopyran forms to their corresponding colored merocyanine forms by UV irradiation and vice versa by visible irradiation or heating [23][24][25]. The detailed investigation of crowned spirobenzopyrans has proved that the photochromic crown compounds, when isomerized from the spiropyran form to the merocyanine form under dark and UV irradiation conditions, can bind metal ions strongly due to the ionic interaction between phenolate anion(s) of the merocyanine form and a metal ion complexed by the crown ether moiety.…”

Switching Properties of a Spiropyran–Cucurbit[7]uril Supramolecular Assembly: Usefulness of the Anchor Approach

“…[33] However, the required conditions (pH 2.3) were far from physiological conditions encountered in bio-relevant contexts. Indeed, the photochromic properties of spiropyrans are of elevated interest for the photocontrol of biological functions, [34][35][36][37][38][39][40] bioimaging, [41][42][43][44][45] optical signal processing and photoswitching in general, [46][47][48][49][50][51][52][53][54][55] as well as chemosensing. [56][57][58][59][60][61] In order to overcome the handicap of a limited photochromic performance of spiropyrans upon direct encapsulation in cucurbiturils we devised herein a novel strategy based on the use of anchor-substituted spiropyrans as guests of cucurbit [7]uril (CB7).…”