Synthesis, crystal structure studies and solvatochromic behaviour of two 2-{5-[4-(dimethylamino)phenyl]penta-2,4-dien-1-ylidene}malononitrile derivatives

Abstract

The synthesis, crystal structure studies and solvatochromic behavior of 2-{(2E,4E)-5-[4-(dimethylamino)phenyl]penta-2,4-dien-1-ylidene}malononitrile, C 16 H 15 N 3 (DCV[3]), and 2-{(2E,4E,6E)-7-[4-(dimethylamino)phenyl]hepta-2,4,6trien-1-ylidene}malononitrile, C 18 H 17 N 3 (DCV[4]), are reported and discussed in comparison with their homologs having a shorter length of the -conjugated bridge. The compounds of this series have potential use as nonlinear materials with second-order effects due to their donor-acceptor structures. However, DCV[3] and DCV[4] crystallized in the centrosymmetric space group P2 1 /c which excludes their application as nonlinear optical materials in the crystalline state. They both crystallize with two independent molecules having the same molecular conformation in the asymmetric unit. The series DCV[1]-DCV[4] demonstrated reversed solvatochromic behavior in toluene, chloroform, and acetonitrile.

Push-pull dyes based on Michler's aldehyde: Design and characterization of the optical and electrochemical properties

“…Malononitrile (EA1) is a weak acceptor [73][74][75][76] whereas EA8 is the strongest one of the series.…”

Crystal structures, syntheses, and spectroscopic and electrochemical measurements of two push–pull chromophores: 2-[4-(dimethylamino)benzylidene]-1H-indene-1,3(2H)-dione and (E)-2-{3-[4-(dimethylamino)phenyl]allylidene}-1H-indene-1,3(2H)-dione

“…For donor-acceptor polyenes, the dominating feature of the absorbance spectrum is the -* transition that results from charge transfer from donor to acceptor. According to recent studies (Bogdanov et al, 2019), it proves that dimethylaminophenyl polyenals have reversed solvatochromism, which is proved by the maxima of the absorption values (…”

DFT and TD-DFT Investigations for the Limitations of Lengthening the Polyene Bridge between N,N-dimethylanilino Donor and Dicyanovinyl Acceptor Molecules as a D-π-A Dye-Sensitized Solar Cell

“…The molecular structure of the polymer, including the DMA and DVC components, is shown in Figure 5 . Bogdanov and his colleagues have recently reported the synthesis of n = 2 and 3, namely 2-{(2E,4E)-5-[4-(dimethyl-amino) phenyl] penta-2,4-dien-1-ylidene} malononitrile and 2-{(2E,4E,6E)-7-[4-(dimethyl-amino) phenyl] hepta-2,4,6-trien-1-ylidene} malononitrile [ 43 ]. The two precursors involved in the synthesis that is being described are an extended aromatic aldehyde and malononitrile.…”