Research AK Bunz: Cruciform Fluorophores

Distyrylbenzenes: Fluorescence Properties and Applications
 
Strukturzeichnung Synthese Distyrylbenzol-Derivat
 
Oligo (ethylene glycol)-substituted, water-soluble distyrylbenzene dialdehydes are versatile amine sensors in water or aqueous buffered solutions. Due to the formation of imines, aminals and hemiaminals, amines can be distinguished by the different fluorescence responses.
 
Fotoreihe Fluoreszenzreaktion auf verschiedene Aminoderivate
 
Strip assays can be constructed by immobilization of DSB derivatives or their hexamethylene-linked polymers on TLC plates. Amines can be easily discriminated via MANOVA analysis of photographic RAW data. Variation of the substrate adds another dimension to this “chemical nose”. Linear discriminant analysis of the fluorescence responses even allows for the discrimination of different albumines in buffered systems.
 
3D-Diagramm Fluoreszenzreaktion von DSB auf verschiedene Albumine
 
By fourfold phenyl substitution of the central core, even aggregation-induced emission characteristics can be bestowed upon DSB derivatives. Drastic phototransformation of these sterically overcrowded molecules results in highly selective formation of benzotetraphene derivatives.
 
Strukturzeichnung Bildung von Benzotetraphen-Derivativen aus DSB
 
Selected References
 
J. Kumpf, U. H. F. Bunz:
"Aldehyde-Appended Distyrylbenzenes: Amine Recognition in Water".
Chem. Eur. J. 2012, 18, 8921-8924.
 
J. Freudenberg, J. Kumpf, V. Schäfer, E. Sauter, S. J. Wörner, K. Brödner, A. Dreuw, U. H. F. Bunz:
"Water-Soluble Cruciforms and Distyrylbenzenes: Synthesis, Characterization, and pH-Dependent Amine-Sensing Properties".
J. Org. Chem. 2013, 78, 4949-4959.
 
J. Kumpf, J. Freudenberg, S. T. Schwaebel, U. H. F. Bunz:
"Amine Sensing with Distyrylbenzenes and Their Hexamethylene-Linked Polymers: Spraying Them On".
Macromolecules 2014, 47, 2569-2573.
 
J. Kumpf, J. Freudenberg, U. H. F. Bunz:
"Distyrylbenzene-aldehydes: identification of proteins in water".
Analyst 2015, 140, 3136-3142.
 
J. Freudenberg, F. Rominger, U. H. F. Bunz:
"New Aggregation-Induced Emitters: Tetraphenyldistyrylbenzenes".
Chem. Eur. J. 2015, 21, 16749-16753.
 
Cruciform Fluorophores
 
Strukturzeichnung Synthese von Cruciform Fluorophores
 
Fotoreihe Fluoreszenz verschiedener Cruciforms
 
Cruciforms change their emission color depending upon their substituent pattern. The effects are dramatic.
 
Bild Orbitalstrukturen verschiedener Cruciforms
 
The orbital structure of cruciforms (XF) is highly variable. In the case of hydrocarbon-based XFs (Top) HOMO and LUMO are congruent, i.e. spatially overlapping, while in the case of the donor-acceptor substituted XFs the HOMO and the LUMO only overlap in the central benzene ring. As a consequence, HOMO and LUMO are independently addressable by different analytes.
 
Foto Fluoreszenz-Aenderung von Cruciforms/Dibutylamino-pyridin-Loesungen auf Zink-triflat
Exposure of the dibutylamino-pyridine XF (see circled structure) to increasing amounts of zinc triflate reveals a rare two stage sensory response that originates from the successive stabilization of the HOMO and the LUMO.
 
2D-Fluoreszenzdiagramm von Cruciforms in Gegenwart verschiedener Metall-Kationen in DCM
 
Exposure of 9 XFs to 20 metal cations in DCM; alkali metals do not show chromic responses; metal triflates give the best results. In this array MnCl2 and CaCl2 were used and these do not show binding. CaOTf2 and MnOTf2 do give color reactions. The colors are obtained by subtraction of the reference from the test samples using ImageJ.
 
Selected References
 
Zucchero, Anthony J.; McGrier, Psaras L.; Bunz, Uwe H. F.:
"Cross-Conjugated Cruciform Fluorophores".
Acc. Chem. Res. 2010, 43(3), 397-408.
 
Wilson, James N.; Bunz, Uwe H. F.:
"Switching of Intramolecular Charge Transfer in Cruciforms: Metal Ion Sensing".
J. Am. Chem. Soc. 2005, 127(12), 4124-4125.
 
Zucchero, Anthony J.; Wilson, James N.; Bunz, Uwe H. F.:
"Cruciforms as functional fluorophores: Response to protons and selected metal ions".
J. Am. Chem. Soc. 2006, 128(36), 11872-11881.
 
Tolosa, Juan; Zucchero, Anthony J.; Bunz, Uwe H. F.:
"Water-soluble cruciforms: response to protons and selected metal ions".
J. Am. Chem. Soc. 2008, 130(20), 6498-6506.
 
Wilson, James N.; Smith, Mark D.; Enkelmann, Volker; Bunz, Uwe H. F.:
"Cruciform pi-systems: effect of aggregation on emission".
Chem. Comm. 2004, (15), 1700-1701.
 
Hauck, Martina; Schoenhaber, Jan; Zucchero, Anthony J.; Hardcastle, Kenneth I.; Mueller, Thomas J. J.; Bunz, Uwe H. F.:
"Phenothiazine Cruciforms: Synthesis and Metallochromic Properties".
J. Org. Chem. 2007, 72(18), 6714-6725.
 
McGrier, Psaras L.; Solntsev, Kyril M.; Schoenhaber, Jan; Brombosz, Scott M.; Tolbert, Laren M.; Bunz, Uwe H. F.:
"Hydroxy-cruciforms".
Chem. Comm. 2007, (21), 2127-2129.
 
McGrier, Psaras L.; Solntsev, Kyril M.; Miao, Shaobin; Tolbert, Laren M.; Miranda, Oscar R.; Rotello, Vincent M.; Bunz, Uwe H. F.:
"Hydroxycruciforms: amine-responsive fluorophores".
Chem. Eur. J. 2008, 14(15), 4503-4510.
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Letzte Änderung: 29.08.2017
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