Fluorescent indicators for cytosolic sodium.

The photophysical behavior of a newly synthesized aza crown-substituted boron−dipyrromethene (BDP) dye and its dimethylamino analogue were investigated with steady-state and time-resolved fluorometry and compared to a reference compound. In solvents more polar than hexane, excitation of the dyes leads to a fast charge transfer from the locally excited (LE) state to a weakly emissive charge-transfer (CT) state. The donor-substituted compounds show dual emission from the LE and CT state, both fluorescence quantum yields being low. The rate constant of excited-state charge separation, calculated from the global analysis of time-resolved emission data, was determined to 1.6 × 1011 s-1 in 1,4-dioxane. The crowned compound forms 1:1-complexes with various alkali and alkaline-earth metal ions, which exist as two conformers in solution. In these complexes, coordination of the cation to the nitrogen donor atom of the crown inhibits the charge-transfer process, leading to a cation-dependent enhancement of the LE em...

Ultrafast Charge Transfer in Amino-Substituted Boron Dipyrromethene Dyes and Its Inhibition by Cation Complexation: A New Design Concept for Highly Sensitive Fluorescent Probes

Chromo- and fluoroionophores. A new class of dye reagents

Multidentate Acyclic Neutral Ligands and Their Complexation

Pyridinium N-phenolate betaine dyes.

Neue Farbstoffe wurden synthetisiert, die ein ionenselektives Kronenethersystem enthalten, bei dessen Komplexierung mit Kationen der Chromophor im Grund- und angeregten Zustand elektronisch unterschiedlich beeinflust wird. Verschiedene Ionentypen rufen verschiedene Farbanderungen hervor. Auser cyclischen Kronenethern mit Chromophoren vom Typ der Azofarbstoffe (1 – 3, 8a, b, 22, 24), des Naphtholblaus (10), des Phenolblaus (11), der Stilbenfarbstoffe (14a, b), der (Mero-)Cyanine (16, 17a, b) und des Konigschen Salzes (19, 20) werden auch an offenkettige Oligoethylenglycolether-Ketten gebundene Chromophore (9, 18) beschrieben. Die teilweise betrachtlichen Anderungen der UV/vis-Absorption einiger Farbstoffe mit Komplexbeteiligung des Auxochroms wie des Antiauxochroms werden erortert.



Ligand Structure and Complexation, L. Ion-selective Crown Ether Dyes



New dyes with an ion-selective crown ether system, the complexation of which with cations influences the ground and excited states of the chromophore to a different extent, have been synthesized. Different types of alkali/alkaline earth metal ions cause different colour changes, significant effects being normally observed with cations fitting selectively into the crown ether units with chromophores of azo dyes (1 – 3, 8a, b, 22, 24), naphthol blue (10), phenol blue (11), stilbene dyes (14a, b), der (mero-)cyanines (16, 17a, b), and of Konig's salt (19, 20). Chromophores bound to open chain oligoethylene glycol ethers are also described. The remarkable changes of light absorption in the course of complexation of some of the dyes are discussed in terms of donor participation of the auxochrome or antiauxochrome.

Johannes Peter Dix

Papers

Ligandstruktur und Komplexierung, L. Ionenselektive Farbstoffkronenether

Ligandstruktur und Komplexierung, XXXIV. Nichtcyclische Neutralliganden mit Phenol‐Endgruppen