Anil‐Synthese 22. Mitteilung über die Herstellung von Styryl‐und Distyryl‐Derivaten des Pyridins

Abstract

2,4-, 2,5-and 2,6-Dimethylpyridines react with anils of aromatic aldehydes in the presence of dimethylformamide and potassium hydroxide to yield the corresponding distyrylpyridines ('anil synthesis'). Under the same reaction conditions (4-methylstyry1)pyridines are converted to (stilbenylviny1)pyridines. Similarly, the Schiff's base derived from pyridine-3-carbaldehyde and p-chloroaniline on treatment with methyl-and p-tolyl-substituted aromatic heterocycles gives the corresponding (heteroaryl-styryl)pyridines, whereas with the Schiff's bases derived from pyridine-2-and -4-carbaldehyde side reactions, such as dimerization followed by disproportionation predominate.Problemstellung. -Styryl-, Distyryl-und (4-Heteroarylstyry1)pyridine sind schon verschiedentlich als optische Aufheller vorgeschlagen worden [2-51. In der vorliegenden Arbeit sol1 untersucht werden, ob Verbindungen dieser Art mit Hilfe der ctAnil-Synthese)) [6] zuganglich sind und welche spektralen Eigenschaften die Zielverbindungen aufweisen.

Redox Control of Stilbylvinylpyridine Chormophore Pairwise Orientations: Towards Solid State Materials for Molecular Electronics

“…Substitution of the stilbene moiety should yield more soluble complexes as well as even longer wavelength absorption. [13] CONCLUSIONS We have developed a successful route for the synthesis of two tripodal ligands containing the stylbylvinylpyridine chromophore. Copper(II) complexes of the ligands display intense circular dichroism spectral amplitudes in the visible wavelength regionthat arise from exciton coupling, allowing for modulation of the amplitude by redox control.…”

“…[11,16] However, addition of one equivalent of NH 4 NCS (yielding 5, [Cu II (1)(NCS)](ClO 4 )) resulted in two d-d bands, 740 nm (ε 178) and 890 nm (ε 220), indicative of predominate trigonal bipyramidal geometry. [13] Visually, the color of 5 changed from green/yellow to yellow revealing the presence of a LMCT band at 405 nm (ε 530). [17] Acquired CD spectra of 3 (A = 90) and 5 (A = 115) displayed bisignate curves with large amplitudes in the visible region as shown in Figure 1a.…”

“…[12] Indeed, it would be worthwhile to try to modify the chromophore so that cheaper, less energetic light would be necessitated for reading the chiroptical signal. Perusal of the literature [13] revealed a chromophore, 6-[2-(stilbene-2-yl)vinyl]pyridine, that should meet the geometric and chromophoric requirements for the next generation design The key questions addressed in this paper are whether ligands for copper complexes can be prepared containing this chromophore, and whether the complexes will show the exciton-coupled circular dichroism spectra required for operation of the switching mechanism. .…”

Bis(pyridylvinyl)diaminobenzenes: synthesis, acidochromism and solvatochromism of the fluorescence

“…The C 2 -symmetrical aza-analogous distyrylbenzenes 7-11 were prepared via Horner olefination from a central bisphosphonate substituted with propyloxy (1) or dipropylamino groups (2) in the 2,5-positions and the pydridinaldehydes (3)(4)(5) Table 1).…”

“…Fundamental systems are polyarylenes, poly(arylenevinylene)s, and poly(aryleneethynylene)s. Besides polymers, oligomers received attention as model systems, as optical brigtheners [3] electronic [4] or scintillating [5] materials. The 1,4-phenylene unit is the prototype for the arylene segment, often substituted with side chains to improve solubility, electrical, and optical properties.…”