Nonlinear Optical Chromophores with Pyrrole Moieties as the Conjugated Bridge:  Enhanced NLO Effects and Interesting Optical Behavior

Abstract

A series of nonlinear optical (NLO) chromophores were successfully prepared, in which pyrrole moieties were the conjugated bridge. In comparison with their analogues containing furan or thiophene groups as the bridge, these chromophores demonstrated similar or enhanced NLO effects (up to 3.3 times) and interesting optical behavior. While the acceptor groups were malononitrile (Mal), 3-phenyl-5-isoxazolone (Iso), and 1,3-diethylthiobarbituric acid (Bar), the chromophores exhibited much blue-shifted maximum absorption wavelengths (lambda max) (up to 36 nm); however, the lambda max of the chromophore containing tricyanovinyldihydrofuran (TCF) as acceptor became much longer than that of the analogue (up to 75 nm).

Two-photon absorption in V-type chromophores with electron-rich heterocyclevinylene bridges

“…4-(Diphenylamino)benzaldehyde, diethyl 4-(diphenylamino)benzylphosphonate and N-hexylpyrrole-2-carbaldehyde were prepared following the procedure reported in refs. [19][20]. All other reagents were used as received.…”

Optimization of polycyclic electron-donors based on julolidinyl structure in push–pull chromophores for second order NLO effects

“…It is well known that due to the stability of pyrrol and furan, they can't be used in production of NLO chromophores [57]. The introduction of electron withdrawing group can improve their stability, but the electron mobility would be simultaneously reduced and the b value also would reduced.…”

Using phenoxazine and phenothiazine as electron donors for second-order nonlinear optical chromophore: Enhanced electro-optic activity

“…Compared with inorganic materials, organic EO materials have many advantages over lower cost, ease of processing, larger EO coefficients and so on [4e8]. The second-order nonlinear optical (NLO) chromophores are the key constructing blocks for organic EO materials [9]. To meet the stringent requirements for the using of devices, one of the most critical challenges is to develop NLO chromophores with large hyperpolarizability (b), excellent thermal and chemical stabilities as well as good transparency [10e12].…”