Synthesis and nonlinear optical properties of aromatic esters with an electron donor and an electron acceptor end group

We synthesized a series of aromatic esters having an electron donating and an electron accepting end group as a new class of nonlinear optical (NLO) a ctive chromophores (ArESn D-A, n = 2,3, D = MeO (as reference), MeS and Me2 N, A = CN). Second-order NLO properties for poled polymer films consisting of poly(methyl methacrylate) (PMMA) doped with 10 wt.-le ArESn D-A (ArESn D -A/PMMA) were investigated. The UV/vis spectra of these polymer films have cutoff wavelengths (lambda(co)) of about 350 similar to 370 nm, which are m uch shorter than in the case of p-nitroaniline (pNA) (lambda(co) = 473 nm) which is a typical strong donor-acceptor (D-pi-A) molecule. In addition, so me of these polymer films exhibit higher second-order nonlinear coefficient s (d(33)) than a PMMA film doped with 10 wt.-% PNA (pNA/PMMA) (2.8 x 10(-9) esu). Namely, ArES3 Me2N-CN (d(33) = 5.6 x 10(-9) esu, 10 wt.-% in PMMA) a nd ArES2 Me2N-CN (3.8 x 10(-9) esu, 10 wt.-% in PMMA) showed excellent seco nd-order NLO activity as well as transparency in the visible region (lambda (co): 363 nm for ArES3 Me2N-CN and 366 nm for ArES2 Me2N-CN, respectively).