Design, characterization and nonlinear optical properties of coumarin appended chalcones: Use of a dual approach

In present investigation, we present designing and characterization of coumarin appended chalcone hybrids using a dual approach consisting of experimental and computational techniques. For the first time, the parent compound 2 ((E)-2-(3-(2,4-dimethoxyphenyl)acryloyl)-3H-benzo[f]chromen-3-one) is successfully synthesized in our lab. The compound 2 is characterized experimentally as well as quantum computational techniques. The results of absorption and emission spectra are compared with those of computationally calculated spectra. A good agreement is found among the experimental and calculated spectra of compound 2. The experimental absorption spectra show maximum absorption and emission peaks at 392 and 461 nm, which are found to be in agreement with their experimental absorption and emission peaks at 393 and 501 nm, respectively. Additionally, we perform analysis of its nonlinear optical (NLO) properties by calculating its second-(β) and third-order <γ> nonlinear polarizabilities. The compound 2 shows reasonably good NLO response with its β and <γ> amplitudes mounting to 120.23 × 10−30 esu and 677.12 × 10−36 esu, respectively. These β and <γ> amplitudes of compound 2 are ∼6 and ∼20 times larger than those of para-nitroaniline (PNA) at BMK/6-311G** level of theory. Based on above structure-property relationship, we also check the effect of substitution of donor groups in the form of further four derivatives i.e. 2a, 2b, 2c and 2d. Interestingly, among these derivatives, the derivative 2d shows a robust NLO response with its β and <γ> amplitudes as large as 218.84 × 10−30 esu and 1515 × 10−36 esu, respectively. The present investigation not only reports the first synthesis of compound 2 but also explores the potential of compound 2 and its derivatives as efficient NLO-phores.