Experimental and Theoretical Study of a New Class of Acceptor Group in Chromophores for Nonlinear Optics:  2-Substituted 4-Methylene-4H-oxazol-5-ones

Abstract

Push−pull organic molecules that combine a polyfunctionalized electron-donating carbazole moiety with a new acceptor group, 4-methylene-4H-oxazol-5-ones, were synthesized and characterized as nonlinear optical chromophores with promising μβ values. First-order hyperpolarizability and dipole moments were calculated by MNDO, AM1 and PM3 methods. Theoretical μβ values were compared to experimental data measured in solution by electric-field-induced second-harmonic generation (EFISH). The different factors that could influence the NLO response, especially the gain or loss of aromatization stabilization during the charge-transfer process, were studied. The thermal stability of these new chromophores is also reported.

7H-1-Benzofuro[2,3-b]carbazole

“…For the biological activity of carbazole derivatives, see: Ramsewak et al (1999); Diaz et al (2002); Zhang et al (2004). For the structures of closely related compounds, see: Chakkaravarthi et al (2008a,b).…”

“…Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97. easily functionalized and covalently linked to other molecules (Diaz et al, 2002). This enables its use as a convenient building block for the design and synthesis of molecular glasses, which are widely studied as components of electroactive and photoactive materials (Zhang et al, 2004).…”

Copper catalyzed synthesis of quinolinopyrano[2,3-b]carbazole derivatives via Povarov reaction

“…The synthesis of O-propargylaldehyde precursor 3 is shown in scheme 1. Demethylation of 2-methoxy-3-formylcarbazole 8 (1) Scheme 1. Synthesis of 9-methyl-2-(prop-2-yn-1-yloxy)-9H -carbazole-3-carbaldehyde (3).…”

Discovery of Novel D‐A and D‐π‐A Structured Carbazole‐Based Formazan Dyes: Synthesis, Characterization, and Spectroscopic Studies

“…Carbazole aldehydes 1 and 2 (5 mmol) synthesized according to literature were dissolved in methanol (50 mL) and acetic acid (1 mL), and then phenylhydrazine (5 mmol) was added with constant stirring at pH 5–6 within 30 min. The reaction mixture was refluxed for 5 h, and resulting carbazole hydrazone compound 9‐methyl‐3‐((2‐phenylhydrazono)methyl)‐9 H ‐carbazole ( 3 ) and 9‐(4‐((2‐phenylhydrazono)methyl)phenyl)‐9 H ‐carbazole ( 4 ) were filtered and recrystallized from methanol .…”