Brookers merocyanine

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Structural formula
Structural formula of Brookers Merocyanine
General
Surname Brookers merocyanine
other names
  • 1-methyl-4 - [(oxocyclohexadienylidene) ethylidene] -1,4-dihydropyridine
  • 23302-83-2
  • NSC87344
  • AC1Q6AZR
  • AC1L5YY0
Molecular formula C 14 H 13 NO
Brief description

red solid

External identifiers / databases
CAS number 23302-83-2
EC number 821-112-3
ECHA InfoCard 100.255.640
PubChem 258436
Wikidata Q4974520
properties
Molar mass 211.26 g mol −1
Physical state

firmly

Melting point

> 220 ° C (decomposition)

safety instructions
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Brooker's merocyanine ( MOED , from the abbreviation of the IUPAC name) is a dye whose color in solution depends on the solvent .

properties

MOED in various solvents.

Brooker's merocyanine was developed by Leslie GS Brooker in 1951. MOED has solvatochromic properties; h, it changes depending on the surrounding solvent or pH to be. absorption spectrum and its fluorescence - emission spectrum .

MOED can exist in two resonance structures , as a neutral molecule and as a zwitterion . In a polar environment the yellow zwitterionic form dominates, while in chloroform or acetone the blue neutral molecule predominates. The more polar the solvent, the lower the frequency or the greater the wavelength .

synthesis

Synthesis scheme of MOED.

The methylation of 4-methylpyridine with methyl iodide produces 1,4-dimethylpyridinium iodide . Its reaction with 4-hydroxybenzaldehyde and subsequent addition of aqueous base generates MOED.

Applications

Because of its solvatochromic properties, MOED, like Reichardt's dye , is used as an indicator of the polarity of a solution. Furthermore, defined colors can be set for solutions by changing the solvent concentration. Other uses are being investigated. MOED changes color and fluorescence when bound to DNA and can be used to determine the concentration of purified DNA solutions.

literature

  • MJ Minch and S Sadiq Shah: "Spectroscopic studies of hydrophobic association. Merocyanine dyes in cationic and anionic micelles". Journal of Organic Chemistry , 44: 3252, 1979.
  • Amaresh Mishra, et al .: "Cyanines during the 1990s: A Review", Chemical Reviews , 2000, 100 (6), 1973-2012 • doi: 10.1021 / cr990402t
  • Christian Reichardt: "Solvatochromic Dyes as Solvent Polarity Indicators", Chem. Rev. , 1994, 94 (8), 2319-2358 • doi: 10.1021 / cr00032a005
  • SJ Davidson2 and WP Jencks: "The Effect of Concentrated Salt Solutions on a Merocyanine Dye, a Vinylogous Amide", Journal of the American Chemical Society , 1969, 91 (2), 225-234 • doi: 10.1021 / ja01030a001
  • Brooker, Keyes, et al .: Studies in the Cyanine Dye Series. XI. The Merocyanines, J. Am. Chem. Soc. , 1951, 73 (11), 5326-5332 • doi: 10.1021 / ja01155a095
  • Brooker, Keyes, et al .: "Color and Constitution. XI.1 Anhydronium Bases of p-Hydroxystyryl Dyes as Solvent Polarity Indicators", J. Am. Chem. Soc. , 1951, 73 (11), 5350-5356 • doi: 10.1021 / ja01155a097
  • Mohamed K. Awad and Shakir T. Abdel-Halim: "Mechanism of Water Attacking on Brooker's Merocyanine Dye and Its Effect on the Molecular and Electronic Structures: Theoretical Study", Bull. Chem. Soc. Jpn. Vol. 79, No. 6, 838-844 (2006)
  • HS Freeman and SA McIntosh, "Some Interesting Substituent Effects in Merocyanine Dyes," Educ. in Chem., 27 (3) 79 (1990).

Individual evidence

  1. ^ Siegfried Hünig, Othmar Rosenthal: Color and Constitution II: Phenolbetainfarbstoffe . In: Justus Liebig's Annals of Chemistry . tape 592 , no. 3 , April 19, 1955, ISSN  0075-4617 , p. 161-179 , doi : 10.1002 / jlac.19555920302 .
  2. ^ Samuel James Davidson, William P. Jencks: Effect of concentrated salt solutions on a merocyanine dye, a vinylogous amide . In: Journal of the American Chemical Society . tape 91 , no. January 2 , 1969, ISSN  0002-7863 , pp. 225–234 , doi : 10.1021 / ja01030a001 .
  3. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
  4. ^ LGS Brooker, GH Keyes, RH Sprague, RH VanDyke, E. VanLare, G. VanZandt, FL White: Studies in the Cyanine Dye Series. XI. The Merocyanines. In: Journal of the American Chemical Society. 73, 1951, pp. 5326-5332, doi: 10.1021 / ja01155a095 .
  5. ^ V. Cavalli, DC da Silva, C. Machado, VG Machado, V. Soldi: The fluorosolvatochromism of Brooker's merocyanine in pure and in mixed solvents. In: Journal of Fluorescence . Volume 16, Number 1, January 2006, pp. 77-86, ISSN  1053-0509 . doi: 10.1007 / s10895-005-0053-9 . PMID 16496216 .
  6. ↑ a b H. Kashida, K. Sano, Y. Hara, H. Asanuma: Modulation of pK (a) of Brooker's merocyanine by DNA hybridization. In: Bioconjugate Chemistry . Volume 20, Number 2, February 2009, pp. 258-265, ISSN  1520-4812 . doi: 10.1021 / bc800335h . PMID 19170520 .
  7. ↑ "Fundamental Studies on Brooker's Merocyanines", Morley et al., J. Am. Chem. Soc. , 1997, 119 (42), 10192-10202 • doi: 10.1021 / ja971477m
  8. ^ NA Murugan, J. Kongsted, Z. Rinkevicius, H. Agren: Demystifying the solvatochromic reversal in Brooker's merocyanine dye. In: Physical chemistry chemical physics: PCCP. Volume 13, Number 4, January 2011, pp. 1290-1292, ISSN  1463-9084 . doi: 10.1039 / c0cp01014f . PMID 21132167 .
  9. ↑ Valerii Z. Shirinian and Alexey A. Shimkin "Merocyanines: Synthesis and Application", in Topics in Heterocyclic Chemistry , Springer, of 2008.