Synthesis, Solution and Solid‐State Fluorescence of 2‐(N‐cycloamino)cinchomeronic Dinitrile Derivatives

Abstract

A facile approach to the synthesis of novel 2‐(N‐cycloamino)cinchomeronic dinitriles showing intense photoluminescence both in solution and solid state was developed. Absorption, fluorescence and solvatochromic properties were investigated. It was found that the 2‐(N‐cycloamino)cinchomeronic dinitrile derivatives containing conjugated aryl moiety show intense emission in nonpolar solvents with fluorescence quantum yield up to 0.8.

Tunable full-color emission of stilbazoles containing a 2-halo-3,4-dicyanopyridine acceptor

“…The mobile halogen atom and two reactive cyano groups will allow a facile modification of the acceptor unit of chromophores by the introduction of the desired moieties. [51][52][53][54][55][56][57][58][59]…”

Dual-State Emission of 2-(Butylamino)Cinchomeronic Dinitrile Derivatives

“…Over the past decade, there has been an exponential increase in the number of publications about the synthetic approaches to compounds showing dual-state emission (DSE) [ 1 , 2 , 3 , 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. This is due to the fact that DSE molecules are more versatile and are therefore intended for a wider range of applications.…”

“…Previously, we reported that compounds with cinchomeronic dinitrile fragments exhibited fluorescence both in solutions and in solid state [ 39 , 40 , 41 , 42 , 43 ]. For example, sulfur-containing cinchomeronic dinitrile derivatives (ethyl 2-((3,4-dicyanopyridine-2-yl)thio)acetates) showed blue fluorescence in organic solvents and a green emission in powders [ 39 ].…”

“…Compounds such as 2-diethylaminocinchomeronic dinitriles were strongly emissive in the solid state and in nonpolar solvents, with fluorescence quantum yields up to 59% [ 40 ]. Compounds such as 2-(pyrrolidin-1-yl)-, 2-(piperidin-1-yl)-, and 2-(azepan-1-yl)-pyridine-3,4-dicarbonitrile derivatives showed even higher emission efficiencies both in solvents and in crystals up to 80% [ 41 ]. In addition, 2-(dicyanomethylene)-1,2-dihydropyridine-3,4-dicarbonitrile derivatives (4-CN-TCPy) possessed solid-state emissions in the red and NIR regions, while their solutions were characterized with strong solvatochromic effects and blue fluorescence [ 42 ].…”