Pyrene Based NLOphoric D‐π‐A‐π‐D Coumarin‐Chalcone and Their Red Emitting OBO Difluoride Complex: Synthesis, Solvatochromism, Z‐scan, and Detailed TD‐DFT Studies

Abstract

NLOphoric D-π-A-π-D coumarin chalcone 5 and their BF 2 complex 6 were designed, synthesized and characterized through Mass, 13 C-NMR, and 1 H-NMR analysis. Their Photophysical properties are extensively studied in solvents of different polarity. On BF 2 complexation of coumarin chalcone shows highly red shift in absorption and emission spectra compared to uncomplexed coumarin chalcone. Positive solvatochromism observed which is well supported by linear and multilinear regression analysis. For BF 2 complexed coumarinchalcone 6 the solvent dipolarity (C SdP ) is the main factor responsible for slightly red shift in absorption spectra, and also for the highly red-shift in emission spectra. Frontier molecular orbital, molecular electrostatic potential and Generalized Mulliken-Hush analysis revealed intramolecular charge transfer in these compounds. Nonlinear optical (NLO) properties for compounds 5 and 6 were studied by solvatochromic and computational method. The linear polarizability (α), first-order hyperpolarizability (β) and second-order hyperpolarizability (γ) of compounds were studied by the time dependent density functional theory using three different functionals namely B3LYP, BHHLYP and CAMÀ B3LYP with the 6-31 G (d) basis set. BF 2 complexed compound 6, show higher values for α e + α v as well as β e + β v compared to compound 5. Third order nonlinear optical susceptibility (χ (3) ) of these compounds obtained by Zscan analysis. Third-order (χ (3) ) non-linear optical properties of BF 2 complexed coumarin-chalcone 6 were observed to be several times higher than those of the uncomplexed coumarinchalcone 5 these justify the design approach.[a] S.

NLO Properties of 2‐Napthol Monoazo Disperse Dyes by DFT and Z‐Scan Technique – A Detailed Study

“…The theoretically observed values of first‐order hyperpolarizability (β) and second‐order hyperpolarizability (γ) for 2‐napthol azo dyes 1–4 are larger than the values for hyperpolarizability of urea . Moreover, the β and γ values of these dyes were compared with the reported donor‐π‐acceptor dyes . We found that β and γ values of these dyes are competes with the reported donor‐π‐acceptor dyes supplementary information (Table S30).…”

Exploring Structural–Photophysical Property Relationships in Mitochondria-Targeted Deep-Red/NIR-Emitting Coumarins

“…In this regard, several coumarin-based dyes have been reported over the last decades (Figure 1), and significant efforts have been devoted to the analysis, understanding, and optimization of their photophysical properties [3,11,12]. [13], ii [14], iii [15], iv [16], v [17], vi [18], vii [19], viii [20], ix [21].…”

“…The rule of thumb in the molecular design of coumarin-based dyes is that the introduction of electron-donating groups (EDG) at positions 6 or 7 (e.g., -OH, -NRR') and electron-withdrawing groups (EWG) at positions 3 or 4 (e.g., -CF3, -COOR, -CN) results in a redshift of the absorption and the emission maxima, due to the existence of a strong intramolecular charge transfer (ICT) process along the coumarin backbone [3]. Extending the π-conjugation system via the fusion of polymethine groups [17] or bulky aromatic scaffolds (e.g., pyrene [18,22], hemicyanine [21,[23][24][25], or BODIPY [20,26,27]) through position 3 is another common strategy to redshift the absorption and [13], ii [14], iii [15], iv [16], v [17], vi [18], vii [19], viii [20], ix [21].…”

“…Examples of coumarin-based fluorophores with increasingly redshifted absorption and emission. Refs: coumarin i [13], ii[14], iii[15], iv[16], v[17], vi[18], vii[19], viii[20], ix[21].…”