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An Ionically Driven Molecular IMPLICATION Gate Operating in Fluorescence Mode
Author(s) -
Rurack Knut,
Trieflinger Christian,
Koval'chuck Anton,
Daub Jörg
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200700858
Subject(s) - chromophore , bifunctional , fluorescence , intramolecular force , crown ether , photochemistry , chemistry , quenching (fluorescence) , molecule , relaxation (psychology) , absorption (acoustics) , ion , stereochemistry , materials science , physics , organic chemistry , catalysis , optics , social psychology , psychology , composite material
An asymmetrically core‐extended boron–dipyrromethene (BDP) dye was equipped with two electron‐donating macrocyclic binding units with different metal ion preferences to operate as an ionically driven molecular IMPLICATION gate. A Na + ‐responsive tetraoxa‐aza crown ether (R 2 ) was integrated into the extended π system of the BDP chromophore to trigger strong intramolecular charge transfer (ICT 2 ) fluorescence and guarantee cation‐induced spectral shifts in absorption. A dithia‐oxa‐aza crown (R 1 ) that responds to Ag + was attached to the meso position of BDP in an electronically decoupled fashion to independently control a second ICT 1 process of a quenching nature. The bifunctional molecule is designed in such a way that in the absence of both inputs, ICT 1 does not compete with ICT 2 and a high fluorescence output is obtained (In A =In B =0→Out=1). Accordingly, binding of only Ag + at R 1 (In A =1, In B =0) as well as complexation of both receptors (In A =In B =1) also yields Out=1. Only for the case in which Na + is bound at R 2 and R 1 is in its free state does quenching occur, which is the distinguishing characteristic for the In A =0 and In B =1→Out=0 state that is required for a logic IMPLICATION gate and Boolean operations such as IF‐THEN or NOT.